研究者詳細 - 平木　英治

論文 - 平木　英治

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Effectiveness Study of Streamlined Fin with Low-Pressure Loss to Improve Heat Dissipation Performance of Heat Sink

Hiroki Seto, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

INTELEC, International Telecommunications Energy Conference (Proceedings) 2024年

掲載種別：研究論文（国際会議プロシーディングス）

In recent years, with the advent of next-generation semiconductors, circuit boards have been miniaturized to accommodate higher frequencies. Miniaturization also means increased heat density. Further miniaturization of switching converters and inverters requires heat sinks that provide excellent heat dissipation performance in a limited volume, and the cylindrical fin type has been commonly used as a heat sink structure. However, cylindrical fin type heat sinks have the problem of large pressure loss when refrigerant passes through them. To solve this problem, streamlined fins and elliptical fin have been proposed to replace cylindrical fin type heat sinks. Although many studies have compared the heat dissipation performance of elliptical and cylindrical fin, few studies have compared it with that of streamlined fins. Therefore, in this paper, a heat sink structure with multiple streamlined fins is constructed. The change in pressure loss due to the change in fin shape and the resulting heat dissipation performance were verified by thermo-fluid analysis and actual device verification, and compared with the conventional cylindrical fin type. As a result, it was confirmed that the streamlined fin structure slightly increases thermal resistance and significantly reduces pressure loss. Comparison of the thermal resistance-pressure loss characteristics showed that the streamlined fins can sufficiently reduce the pressure loss for the same thermal resistance value. In the case of forced air cooling, the heat dissipation performance of the streamlined fins could be expected to improve with fan selection.

DOI： 10.1109/INTELEC60315.2024.10679005

Compact Hardware Implementation of Power Factor Control for LLC converter with Event-Driven-Timer Based Digital Controller

Toshiyuki Zaitsu, Yuto Yoshimura, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki, Kazuhiro Horii

Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC 2015 - 2020 2024年

掲載種別：研究論文（国際会議プロシーディングス）

LLC converter is well known as an attractive topology however, it suffers from system stability degradation depending on load conditions, which has limited use for many applications. The previous study addressed this problem by proposing a novel control, called the 'power factor (cosθ) control', which adjusts the phase difference θ between the inverter voltage and primary current of the LLC half-bridge instead of adjusting the operating frequency. However, the previous prototype required a complicated analog circuit for the control, which appeared difficult for practical application. This paper aims at achieving a compact implementation of the control circuit. A special "Event-Driven-Timer Based"digital control is adopted which can automatically track the timing and frequency by detecting the resonant trigger point and turning on the main switch. The prototype board exhibited great size reduction of the control circuit as well as excellent controllability, supporting promising features for practical application.

DOI： 10.1109/APEC48139.2024.10509360

Feasibility of Active Reactance Compensator for Autonomously Maximizing Repeater Coil Current of Wireless Power Transfer System Against Variations in Resonant Frequency and Magnetic Coupling Intensity

Masataka Ishihara, Kazuhiro Umetani, Akihiro Konishi, Eiji Hiraki

IEEE Access 12 98175 - 98188 2024年

掲載種別：研究論文（学術雑誌）

In resonant inductive coupling wireless power transfer systems, a repeater resonator is crucial in expanding the charging area, enabling efficient power supply to receivers, such as small Internet of Things (IoT) devices sparsely distributed in a wide area. However, the repeater current is highly susceptible to deviations in resonance frequency due to manufacturing tolerance and aging, as well as to the magnetic coupling between the transmitter and repeater coils, potentially leading to insufficient amplitude. Consequently, the magnetic field generated by the repeater decreases and the receiver may be difficult to obtain sufficient power from the transmitter via the repeater. To address this problem, this paper proposes a wireless power transfer system with active reactance compensators incorporated in the repeater and the transmitter. The proposed system can equivalently adjust the resonant frequencies of the transmitter and repeater to stably maximize the repeater coil current regardless of the variations in the resonant frequency and the magnetic coupling intensity. Experiments successfully verify that the proposed system can provide a more stable and larger repeater current and output power than the conventional system against the variations in the magnetic field intensity and the resonant frequency of the repeater, validating the feasibility of the proposed system for practical utilization of the repeater in expanding the charging area.

DOI： 10.1109/ACCESS.2024.3428864

Parasitic Inductance Network Modeling Method for Power Module Inner Wirings Based on Inductance Matrix Measurement

Kotaro Kobashi, Kazuhiro Umetani, Masataka Ishihara, Hiroto Sakai, Yuta Okawauchi, Takuto Hayashi, Eiji Hiraki

Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC 2530 - 2536 2024年

掲載種別：研究論文（国際会議プロシーディングス）

In recent years, using SiC devices for fast switching have led to the miniaturization of power modules. However, due to the high di/dt of fast switching, false triggering and parallel oscillation caused by high di/dt have become an issue. A method for extracting equivalent circuits, including parasitic inductance, is essential to solve these issues. In power modules, multiple devices are often connected in parallel to meet the demand for high power density. Therefore, complex mutual coupling between wirings makes it challenging to determine the equivalent circuit, including parasitic inductance. In this paper, we propose an equivalent circuit extraction method for power modules that focuses on current loops instead of focusing on the wiring section as in previous studies. The proposed method can extract the effective inductance considering the mutual coupling between wires with fewer measurements than the conventional method. We first summarize the concept of inductance and explain the advantages of the extraction method, focusi ng on current loops. Next, the equivalent circuit, including the parasitic inductance of a double-pulse test circuit board with SiC-MOSFETs connected in parallel, is extracted using the proposed method. To confirm the validity of the proposed method, a double resonance system was constructed using the test circuit board wiring, and the frequency characteristics of the actual measurement and the simulation based on the extracted parasitic inductance were compared.

DOI： 10.1109/APEC48139.2024.10509099

GaN-HEMT Power Module of Aluminum-Clad Printed Circuit Boards for Small Power Loop Inductance and High Cooling Performance

Kazuhiro Umetani, Yu Takehara, Masataka Ishihara, Eiji Hiraki

IEEE Transactions on Power Electronics 39 ( 10 ) 12047 - 12052 2024年

掲載種別：研究論文（学術雑誌）

Gallium nitride high-electron-mobility transistors (GaN-HEMTs) are promising for high-speed switching capability and small on-resistance. However, large turn-off surge and limited cooling capability due to their small chip size are hindering their application to high power conversion. To solve these problems, this letter proposes a novel power module structure with small power loop inductance and small thermal resistance based on recently proposed power module structures. The proposed structure comprises two aluminum-clad printed circuit boards (PCBs) that sandwich the GaN-HEMT devices. These PCBs generate eddy current inside the aluminum base to reduce power loop inductance and provide an additional thermal path to improve the cooling performance. These features were tested by an experiment that compared 3-kW half-bridge prototype power modules of the proposed and conventional structures. As a result, the proposed structure revealed power loop inductance of 1.4 nH and thermal resistance of 0.72 K/W, which corresponded to a reduction by 53% and 20%, respectively, compared to the conventional structure.

DOI： 10.1109/TPEL.2024.3431615

Non-Isolated Interleaved High Step-Down DC-DC Converter with Reduced Switched Capacitor Stages and Automatic Current Sharing

Kazuhiro Umetani, Fumie Ishitani, Taira Shirahase, Masataka Ishihara, Eiji Hiraki

INTELEC, International Telecommunications Energy Conference (Proceedings) 2024年

掲載種別：研究論文（国際会議プロシーディングス）

A high-voltage dc power supply system is an attractive solution for reducing the system cost and improving efficiency. This system needs compact but high-efficiency high-step-down converters to exploit the benefits. This paper proposes a novel converter for a better candidate than traditional converters. The proposed converter is a non-isolated high step-down converter utilizing the switched capacitor technology. Compared to conventional similar topologies, the number of switched capacitor stages can be reduced, enabling the compact converter design. Furthermore, this converter has interleaved output, which can downsize the magnetic devices. The current of the interleaved output is automatically balanced without special control, enabling simple controller implementation. These features were successfully verified by the experiment.

DOI： 10.1109/INTELEC60315.2024.10678985

Design of Embedded Experiments in Power Electronics Class

Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

2023 IEEE 10th International Conference on E-Learning in Industrial Electronics, ICELIE 2023 2023年

掲載種別：研究論文（国際会議プロシーディングス）

Power electronics is an electric circuit technology for electric power conversion and is taught in many universities due to its importance in modern society. This technology is traditionally taught in lecture courses, which are based on the operation analysis of the power conversion circuits based on the circuit theory. However, unlike other fields regarding the electric circuit, the quality of the power conversion circuits is fundamentally dependent on the non-ideal features of the circuit elements as well as the size including the cooling system. Therefore, the practical design of the power conversion circuit profoundly relies not only on understanding the basic circuit operation but also on the knowledge of the actual circuit elements, including their non-ideal features. The traditional class based on theoretical circuit operation analysis was difficult to cover the latter knowledge, which may have resulted in insufficient educational achievement in power electronics technology. This paper proposes a teaching approach that embeds mini-experiments in the lecture to overcome this difficulty. These mini-experiments are carefully designed to be seamlessly combined with the lecture and shown to the students during the lecture by utilizing IT-based measurement instruments. According to the students' survey, the students felt the improvement of the lecture quality by the embedded experiment, although the difficulty in the time scheduling for the embedded experiment is a remaining problem to be solved in future studies.

DOI： 10.1109/ICELIE58531.2023.10313105

Artificial-Voice-Based Conversational Lecture Video Clips for Flipped Classroom.

Kazuhiro Umetani, Yoshitaka Toyota, Masataka Ishihara, Eiji Hiraki

ISIE 1 - 7 2023年

Power Loop Inductance Optimization Strategy for Eliminating Turn-off Switching Surge for GaN-HEMT Switching Device

Kazuhiro Umetani, Kento Tanohara, Koki Abe, Masataka Ishihara, Eiji Hiraki

2023 25th European Conference on Power Electronics and Applications, EPE 2023 ECCE Europe 2023年

掲載種別：研究論文（国際会議プロシーディングス）

The gallium nitride high electron mobility transistors (GaN-HEMTs) are increasingly applied for high-power switching converters. However, their fast switching in high-power applications tends to generate enormous switching surges at the turn-off, which may destroy the switching device. This problem can be mitigated by optimizing the wire structure to minimize the power loop inductance, although satisfactory reduction of this inductance is difficult in many practical designs. This paper address this issue by optimizing the power loop inductance rather than seeking the entire elimination of this inductance. This paper analytically elucidates the existence of the optimal power loop inductance that ideally generates no turn-off surge with fast-switching GaN-HEMTs. An experiment supported the analytical result, suggesting the optimal design of power loop inductance is promising for the power module design of GaN-HEMTs.

DOI： 10.23919/EPE23ECCEEurope58414.2023.10264302

Autonomous Resonant Frequency Tuner for a 6.78 MHz Inductive Coupling Wireless Power Transfer System to Stably Maximize Repeater Current

Akihiro Konishi, Kazuhiro Umetani, Member Masataka Ishihara, Eiji Hiraki

IEEJ Journal of Industry Applications 12 ( 2 ) 215 - 227 2023年

掲載種別：研究論文（学術雑誌）

Recently, the resonant inductive coupling wireless power transfer (RIC-WPT) technique is being widely used to charge small IoT devices dispersed in a wide area, e.g., an office desk and warehouse rack. In this application, the repeater is utilized to expand the chargeable area without an additional AC power source. The repeater comprises a LC resonator commonly with a high-quality factor to induce large current in the repeater coil. However, this causes the problem that the repeater performance is highly susceptible to the variation in its resonant frequency due to the manufacturing tolerance of coil inductance and resonant capacitance as well as the variation of the magnetic coupling between the transmitter and repeater coils. To solve this problem, a previous study has proposed a concept of the autonomous resonant frequency tuning circuit to stably maximize repeater coil current, although this study implemented a part of this control system as a practical circuit. This paper aims to develop a complete autonomous resonant frequency tuning circuit that implements the aforementioned concept. The proposed circuit adjusts the resonant frequencies of the transmitter and repeater by utilizing the Automatic Tuning Assist Circuits. These frequencies are optimized using the infrared wireless signal communication from the transmitter to the repeater. Along with the operating principle of the proposed circuit, this study presents detailed circuit design as well as the experimental results, which verified the stable autonomous maximization of the repeater coil current against the variation in the resonant frequency of the repeater resonator.

DOI： 10.1541/ieejjia.22010814

Introduction of Circuit Simulator to Power Electronics Education in Interdisciplinary Educational Environment

Eiji Hiraki, Masataka Ishihara, Kazuhiro Umetani

2023 IEEE 10th International Conference on E-Learning in Industrial Electronics, ICELIE 2023 2023年

掲載種別：研究論文（国際会議プロシーディングス）

In recent years, the engineering field is becoming more and more complicated, and collaboration with other disciplines is becoming more critical. As a result, interdisciplinary programs are rising at the graduate level and higher education stages, centered around universities. One drawback of this trend is that students who lack foundational knowledge related to certain lectures may take specialized courses. This can lead to significant differences in the knowledge acquired by the students, depending on how the lecture content is tailored to accommodate their respective levels. To address this issue, various efforts have been made to solve this problem. This paper presents a case study of introducing a circuit simulator to conduct a semiconductor power conversion engineering, in a class with not a few students who do not have circuit theoretical backgrounds.

DOI： 10.1109/ICELIE58531.2023.10313100

Rectifier-Integrated Printed-Circuit-Board Winding Structure of Secondary-Side Center-Tapped Transformer for Suppressing Parasitic Resonance between Decoupling Capacitors

Hiromu Saeki, Kazuhiro Umetani, Tomohide Shirakawa, Masataka Ishihara, Eiji Hiraki

ICPE 2023-ECCE Asia - 11th International Conference on Power Electronics - ECCE Asia: Green World with Power Electronics 1731 - 1737 2023年

掲載種別：研究論文（国際会議プロシーディングス）

In many practical LLC DC-DC converters, the isolation transformer is commonly designed to have a secondary-side center-tapped configuration with one-turn secondary windings. Conventionally, the rectification circuit is installed outside the transformer. However, the recent LLC converters are designed to operate at increasingly high switching frequencies, which indispensably causes the proximity effect in the rectification circuit as well as the wire that connects this circuit to the transformer secondary windings, resulting in large copper loss generation outside the transformer. The previous paper addressed this problem by proposing a secondary winding structure integrating the rectification circuit, although this structure caused the parasitic resonance inside the rectification circuit and reduced the rectification efficiency. To prevent the reduction in the rectification efficiency, this paper proposes an improved winding structure based on the printed-circuit-board technology for suppressing parasitic resonance. The experiment revealed further improvement in the rectification efficiency compared to the previously-proposed structure, suggesting the effectiveness of the proposed winding structure.

DOI： 10.23919/ICPE2023-ECCEAsia54778.2023.10213516

GaN-HEMT Power Module Structure with Single-sided and Double-sided Aluminum-Clad Printed-Circuit Boards for Small Power Loop Inductance and High Cooling Performance

Kazuhiro Umetani, Yu Takehara, Masataka Ishihara, Eiji Hiraki

2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023 5531 - 5537 2023年

掲載種別：研究論文（国際会議プロシーディングス）

Gallium nitride high electron mobility transistor (GaN-HEMT) is attractive for fast switching capability and small on-resistance, which motivates researchers to adopt GaN-HEMT for high-power applications. High-power application of GaN-HEMT requires small power loop inductance to suppress switching surge under fast switching but also requires a large power module size for sufficient cooling performance by heat spreading, which results in large wire length and increases the power loop inductance. This paper addresses this problem by proposing a module structure with small power loop inductance and high cooling capability. The proposed module structure incorporates double-sided and single-sided aluminum-clad printed-circuit boards (PCBs) that sandwich the switching devices. These PCBs offer double-sided cooling and small power loop inductance owing to the eddy current generation inside the aluminum clad. A 3kw half-bridge prototype module was constructed to test the proposed structure in comparison with the preceding module structure, which incorporates the double-sided FR4 PCB for the power circuit and the single-sided aluminum-clad PCB for heat spreading. The result successfully revealed that the proposed structure exhibited a small power loop inductance of 1.4nH and a small thermal resistance of 0.72/W, which indicates the reduction in power loop inductance by 53% and in thermal resistance by 20%.

DOI： 10.1109/ECCE53617.2023.10362213

Origin of Common Source Inductance in Power Device Packages with Kelvin Source Terminal

Kotaro Kobashi, Akihiro Konishi, Kazuhiro Umetani, Masataka Ishihara, Takuto Hayashi, Eiji Hiraki

2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023 5510 - 5516 2023年

掲載種別：研究論文（国際会議プロシーディングス）

The kelvin-source packages are becoming popular for high-power ultrafast switching devices to reduce the common source inductance (CSI), which induces the noise voltage in the gating circuit at the transitional change of the drain current and causes false triggering. Despite its importance, however, the actual measurement of CSI has not been reported for kelvin-source packages due to their small inductance values. This paper measured the CSI of typical kelvin-source package TO-247-4L. The result revealed that the CSI of this kelvin-source package ranged 0.2nH-0.7nH, which cannot be neglected at a switching speed greater than 1A/ns. Furthermore, this variation in CSI was found to arise from the magnetic coupling between the bonding wires of power source and gating source, implying that separating the bonding wires can further reduce the CSI.

DOI： 10.1109/ECCE53617.2023.10362400

Suppression Strategy for Oscillatory False Triggering Between Two paralleled GaN-HEMTs Based on Optimization of Parasitic Inductance

Ryoma Yoshida, Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023 5406 - 5413 2023年

掲載種別：研究論文（国際会議プロシーディングス）

Recently, GaN-HEMTs are expected to be applied to high-power applications because of their high-speed switching and low on-resistance, which enables high-efficiency. In high-power applications, the GaN-HEMT is commonly connected in parallel to reduce the current stress. However, the paralleled GaN-HEMTs often suffer from oscillatory false triggering due to fast switching capability. If oscillatory false triggering is occurred, may damage the circuit so that we must be prevented in industrial products. To solve this problem, the purpose of this study is to elucidate design strategy for the parasitic inductance to prevent the oscillatory false triggering in the paralleled GaN-HEMTs. To achieve the purpose, this paper analyzes an equivalent circuit of the single-pulse test circuit with two paralleled GaN-HEMTs after the turn-off transition. As a result, we derived design strategy for parasitic inductances to prevent the oscillatory false triggering and verified the validity of the design strategy by simulations and experiments.

DOI： 10.1109/ECCE53617.2023.10362878

Differences in Visibility of Students' Proficiency by Grading Methods in Energy Electronics-related Lectures Based on DX Format

Eiji Hiraki, Masataka Ishihara, Kazuhiro Umetani

2022 IEEE 9th International Conference on e-Learning in Industrial Electronics (ICELIE) 2022年10月

Solution-Oriented Teaching Method of Electric Power Circuit Design for Online On-demand Video Streaming Lecture Course

Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

2022 IEEE 9th International Conference on e-Learning in Industrial Electronics (ICELIE) 2022年10月

Frequency Dependence Deterioration of AC Resistance in Large-Diameter Litz Wire for High Power Induction Heating

Shota Kawahara, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

2022 IEEE Energy Conversion Congress and Exposition (ECCE) 2022年10月

Cross-Interference Free 6.78 MHz Multiple-Transmitter Using Power Factor Based Control for Wide-Area Wireless Power Transfer Systems

Masataka Ishihara, Kodai Matsuura, Akihiro Konishi, Kazuhiro Umetani, Eiji Hiraki

2022 IEEE Energy Conversion Congress and Exposition (ECCE) 2022年10月

Analytical Derivation of Phase-Current Waveform for Elimination of Torque and Input-Current Ripples of Switched Reluctance Motor Operating Under Magnetic Saturation

Takayuki Kusumi, Kosuke Kobayashi, Kazuhiro Umetani, Eiji Hiraki

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 58 ( 4 ) 5248 - 5261 2022年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Switched reluctance motors (SRMs) have recently attracted researchers' attention owing to their robust mechanical construction, high thermal tolerance, and strong cost-effectiveness, which are promising for vehicle propulsion. However, they tend to generate large ripples in the torque and input currents to the inverter; this deteriorates the driving comfort, and damages the battery lifetime. Preceding articles have investigated using the phase currents of SRMs to eliminate these ripples. However, these articles had difficulties in sufficiently eliminating these ripples in operations under magnetic saturation. This article further evolves one of these preceding articles, and proposes a derivation method for the phase-current waveform for improving the elimination of the torque and input-current ripples in operation under magnetic saturation. The proposed method analytically determines the phase-current waveform based on a nonlinear behavior model of the SRM while considering the magnetic saturation. A finite-element-method-based simulation and experiment are performed to evaluate the proposed method. These results reveal the successful reduction of the torque and input-current ripples under the magnetic saturation relative to a preceding study, supporting the appropriateness of the proposed method.

DOI： 10.1109/TIA.2022.3172898

High-Efficiency Solenoid Coil Structure for Induction Heating of Cylindrical Heating Object

Daiki Miyake, Kazuhiro Umetani, Shota Kawahara, Masataka Ishihara, Eiji Hiraki

IEEE International Symposium on Industrial Electronics 2022-June 307 - 313 2022年

掲載種別：研究論文（国際会議プロシーディングス）

The solenoid coil is a typical heating coil structure for induction heating of cylindrical heating objects. Conventionally, a bare solenoid coil without any soft-magnetic core has been commonly utilized. However, this conventional structure suffers from worse heating efficiency caused by the large coil copper loss and the low magnetic field induction at the heating object. This paper addresses these difficulties by proposing a novel heating coil structure. In addition to the solenoid coil, the proposed heating coils structure further incorporates the soft-magnetic cores that cover the outer coil periphery and the coil opening edges. These additional cores can reduce the local intense magnetic field around the coil, thus mitigating the eddy current induction inside the wire to reduce the copper loss, and also can increase the magnetic field inside the heating object, thus increasing the heat generation. The simulation was carried out to test the effectiveness of the proposed heating coil structure. The results inferred the reduction of the coil copper loss by 25% and the increase in the heat generation in the heating object by 53%, both of which suggest the promising features of the proposed heating coil structure for heating the cylindrical magnetic material. The heating operation of the proposed heating coil structure was tested by the experiment, although the current prototype was found to have larger power loss than expected from the simulation. The reason may lie in unintended eddy current generation of the metal case of the heating coil, which will be addressed in future work.

DOI： 10.1109/ISIE51582.2022.9831459

Secondary-Side Resonating LLC Converter for Reducing Transformer Voltage in High Power Applications

Hayato Nakamura, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

2022 International Power Electronics Conference, IPEC-Himeji 2022-ECCE Asia 547 - 554 2022年

掲載種別：研究論文（国際会議プロシーディングス）

The data centers of the telecommunication infrastructure are recently consuming more electric power than before. This increasing electrical burden is requiring a small but high-power isolated power converter with a high step-down ratio. Conventionally, the LLC converter is regarded to be a promising candidate, although this converter needs vacant space for galvanic isolation due to extremely high voltage caused by the resonance in the primary side, i.e. high voltage side, of the isolation transformer, which hinders the compact implementation inside the server computers in high power design. The purpose of this paper is to propose a novel LLC converter topology to reduce this extremely high voltage by locating the LC resonator on the secondary side. The performance analysis revealed that the proposed converter exhibits a similar frequency-voltage characteristic enabling the boost and buck operation modes as well as the small rectifier conduction loss similar to the full-wave rectifier with a center-tapped transformer. The simulation confirmed the operating principles and reduction of the resonance voltage amplitude of the proposed LLC converter in comparison with the conventional LLC converter. Furthermore, the experiment also supported the operating principles, which suggests the usefulness of the proposed converter for a high voltage dc power supply system.

DOI： 10.23919/IPEC-Himeji2022-ECCE53331.2022.9806826

Phase-Shift Based on Power Factor Control for LLC Converter with High Output Stability Against Load Fluctuation

Kenta Yamada, Kazuhiro Umetani, Eiji Hiraki, Masataka Ishihara

2022 IEEE 7th Southern Power Electronics Conference, SPEC 2022 2022年

掲載種別：研究論文（国際会議プロシーディングス）

The LLC converter is a very effective topology for miniaturization of power supplies. However, its application is currently limited. That is because of the problem of degraded system stability when the load condition changes. This paper proposed a practical control circuit that controls the power factor cos\theta by adjusting the phase difference \theta between the inverter voltage and primary current of the LLC converter to control the output voltage to address this problem. As a result, experimental result confirm that the proposed control method has robust control characteristics against wide load impedance and shows low output impedance regardless of the output voltage.

DOI： 10.1109/SPEC55080.2022.10058371

A Secondary-Side Resonant LLC converter for Reducing Resonance Voltage with Boost Mode Operation Using Resonance Including Current Doubler Rectifier

Hayato Nakamura, Naoyuki Yokoshima, Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki, Tatsuya Miyazaki, Yuta Okawauchi, Ken Nakahara

2022 IEEE 7th Southern Power Electronics Conference, SPEC 2022 2022年

掲載種別：研究論文（国際会議プロシーディングス）

Isolated DC-DC converter in data centers are now required to have a high step-down ratio and be suitable for high-power applications. As such DC-DC converters, LLC resonant converters have been attracting attention. However, the LLC resonant converter generates a large resonance voltage at the resonator, so the resonance inductor and resonance capacitor must be large in size. Recently, a previous study proposed a secondary-side resonance LLC converter to reduce the resonant voltages of the passive components. Nevertheless, this LLC converter requires a resonant capacitor in parallel with the rectifier to achieve boost mode operation, which complicates the circuit operation and design. Therefore, we have considered the use of the magnetizing inductance of the coupled transformer of the current doubler rectifier as a method to realize the boost mode operation. In this paper, we propose a new method of boost mode operation for LLC resonant converter using secondary-side resonance and the current doubler rectifier.

DOI： 10.1109/SPEC55080.2022.10058227

Sinusoidal-Flux Reluctance Machine Driven with Three-Phase Inverter for Improving Power Density with Reduced Torque and Input Current Ripples

Masaki Iida, Kazuhiro Umetani, Takayuki Kusumi, Masataka Ishihara, Eiji Hiraki

2021 23rd European Conference on Power Electronics and Applications, EPE 2021 ECCE Europe 2021年9月

掲載種別：研究論文（国際会議プロシーディングス）

Reluctance machines such as the switched reluctance machines (SRMs) and the synchronous reluctance machines (SynRMs) are recently investigated for propulsion motors of the electrified vehicles owing to their robust mechanical construction, high thermal tolerance, and cost-competitiveness. However, practical application of the reluctance machines to the vehicle propulsion has been hindered by the fact that the conventional SRMs and SynRMs are difficult to meet all the three preferable features for the vehicular application: 1. High power density, 2. Low torque and input-current ripples, 3. Being drivable by the normal three-phase inverter. This paper addresses this issue by proposing a novel reluctance machine. The prominent features of the proposed reluctance machine are the sinusoidal reluctance profile and the delta-connected phase windings, both of which differ from conventional reluctance machines. Along with the theoretical discussion of the basic operating principles of the proposed reluctance machines, this paper presents a simple performance estimation of the proposed machine, the SRM, and the SynRM, which supported that the proposed machine can meet the three preferable features. Furthermore, the experiment successfully supported the operating principles of the proposed machine, suggesting the feasibility of the proposed machine for vehicle applications.

Autonomous System Concept of Multiple-Receiver Inductive Coupling Wireless Power Transfer for Output Power Stabilization against Cross-Interference among Receivers and Resonance Frequency Tolerance

Masataka Ishihara, Keita Fujiki, Kazuhiro Umetani, Eiiji Hiraki

IEEE Transactions on Industry Applications 57 ( 4 ) 3898 - 3910 2021年7月

掲載種別：研究論文（学術雑誌）

Multiple-receiver resonant inductive coupling wireless power transfer (RIC-WPT) technique is emerging as a promising charging method for multiple household appliances, mobile devices, and wearable devices. However, this technique often suffers from output power fluctuation owing to the cross-interference among receivers as well as the manufacturing and aging tolerance of the resonant frequency (i.e., resonant frequency tolerance). This article proposes an autonomous RIC-WPT system concept to solve this difficulty. The proposed concept addresses the cross-interference and resonant frequency tolerance by incorporating the following two functions. First, the amplitude of the transmitter current is controlled to have a constant amplitude. Second, the phase of each receiver current is controlled to be orthogonal to that of the transmitter current by using an active reactance compensator installed in each receiver. The experiment of a two-receiver RIC-WPT system successfully verified that the two functions of the proposed system concept can stabilize the output voltage against the cross-interference and resonant frequency tolerance.

DOI： 10.1109/TIA.2021.3081071

Analytical Formulation of Copper Loss of Litz Wire With Multiple Levels of Twisting Using Measurable Parameters

Kazuhiro Umetani, Shota Kawahara, Jesus Acero, Hector Sarnago, Oscar Lucia, Eiji Hiraki

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 57 ( 3 ) 2407 - 2420 2021年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Litz wire has been widely utilized in power transformers and inductors as a wire with low copper loss at high-frequency operation. The Litz wire is commonly made of many thin isolated strands twisted in multiple levels. Due to its complicated structure, the copper loss prediction of the Litz wire has been difficult, hindering the design optimization of the Litz wire structure. To overcome this difficulty, preceding studies have investigated the analytical copper loss models of the constituting elements of the Litz wire, i.e., the strands and the bundles of strands. The purpose of this article is to propose an analytical copper loss model of the Litz wire by utilizing these preceding knowledge. The proposed model is formulated only with parameters that can be measured by basic testing instruments. Besides, the proposed model considers the bundle structure of the Litz wire, which affects the local ac current distribution, and the twisting pitch, which causes the inclination of the Litz wire strands. The proposed model was tested by comparing the analytical prediction and experimental measurements of the ac resistance of commercially available Litz wires. As a result, the predicted ac resistance showed good agreement with the measured ac resistance, suggesting the appropriateness of the proposed model.

DOI： 10.1109/TIA.2021.3063993

Industrial Electronics Education: Past, Present, and Future Perspectives

Oscar Lucia, Joao Martins, Yousef Ibrahim, Kazuhiro Umetani, Luis Gomes, Eiji Hiraki, Houcine Zeroug, Milos Manic

IEEE INDUSTRIAL ELECTRONICS MAGAZINE 15 ( 1 ) 140 - 154 2021年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Industrial electronics (IE) covers a wide range of technologies and applications, being a key enabling technology for numerous industrial, domestic, and biomedical uses, among others. In this context, IE education has become a relevant and challenging topic for society and industry. This article covers its evolution and state-of-the-art methodologies and provides an overall view of its status around the world. Finally, future trends and challenges in IE education are discussed.

DOI： 10.1109/MIE.2020.3002488

Feasibility of Sinusoidal Flux Drive Design of Reluctance Motor for Reducing Torque and Input Current Ripples with Three-Leg Inverter

Masaki Iida, Takayuki Kusumi, Kazuhiro Umetani, Eiji Hiraki

2021 IEEE 19TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (PEMC) 439 - 446 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Reluctance motors, represented by the switched reluctance motor (SRM) and the synchronous reluctance motor (SynRM), are attractive for vehicle propulsion owing to their high thermal tolerance and simple mechanical construction. However, the SRM exhibits large torque and large input current ripples, deteriorating driving comfort and battery lifespan. Furthermore, a driving system of the SRM requires the special inverter topology with additional switching or rectifying devices, leading to the cost-up. Meanwhile, the SynRM does not have these drawbacks, although this motor tends to be difficult to cover the wide range of the torque and the rotation speed required for vehicle propulsion because of large phase flux induction. To solve the obstacles of these conventional reluctance motors, this paper proposes a novel reluctance motor. The proposed reluctance motor is based on magnetization by the sinusoidal phase flux waveform, whereby the torque and input current ripples are eliminated using a common three-leg inverter without inducing large phase magnetic flux. This paper presents the operating principles of the proposed reluctance motor as well as analysis and simulation results in comparison with the SRM and the SynRM. As a result, the proposed reluctance motor is elucidated to reduce the torque and input current ripples with the three-leg inverter. Furthermore, the proposed reluctance motor can improve the torque range and rotating speed range compared to the SynRM because of the sinusoidal flux waveform with reduced amplitude. These results imply feasibility of the proposed motor for vehicle propulsion.

DOI： 10.1109/PEMC48073.2021.9432579

Parasitic Inductance Design for Preventing Oscillatory False Triggering of Parallel-Connected GaN-FETs.

Yusuke Hatakenaka, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki, Hiroshi Tadano

IECON 2021 - 47th Annual Conference of the IEEE Industrial Electronics Society(IECON) 1 - 8 2021年

Tiny Approaches to the Interactive Online Lectures Under the COVID-19 Pandemic.

Eiji Hiraki, Masataka Ishihara, Kazuhiro Umetani

IECON 2021 - 47th Annual Conference of the IEEE Industrial Electronics Society(IECON) 1 - 4 2021年

Feasibility of Parasitic Drain Inductance Design for Minimizing Switching Loss in Bridge Circuits Using GaN-FETs.

Koki Abe, Masataka Ishihara, Yusuke Hatakenaka, Kazuhiro Umetani, Eiji Hiraki

30th IEEE International Symposium on Industrial Electronics(ISIE) 1 - 5 2021年

A Control Method Based on Power Factor for Improving Output Voltage Stability and Efficiency of LLC Converter in Wide Range of Output Voltage and Load Impedance

Kazuhiro Umetani, Kota Shimomura, Kenta Yamada, Taichi Kawakami, Masataka Ishihara, Eiji Hiraki

2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 3436 - 3443 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The LLC converter is attractive for its small volume and comparatively high efficiency. However, the application of this converter is limited to the power supply to a static load with almost constant output voltage and current because the LLC design covering a wide range in the output voltage and the load variation can deteriorate the output voltage stability and efficiency. This paper addresses this issue by proposing a novel control method. Unlike the conventional control, which adjusts the operating frequency to stabilize the output voltage, the proposed control adjusts the power factor of the transformer primary-side to achieve the same excellent dynamic performance as the buck chopper. Simulation supported the effectiveness of the proposed control at a wide load variation range.

DOI： 10.1109/ECCE47101.2021.9595420

Multiple-Transmitter with Phase-Shift and Dynamic ZVS Angle Controls at Fixed Operating Frequency for Cross-Interference Free Wireless Power Transfer Systems

Kodai Matsuura, Masataka Ishihara, Akihiro Konishi, Kazuhiro Umetani, Eiji Hiraki

2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 5767 - 5774 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Resonant inductive coupling wireless power transfer (RIC-WPT) systems with multiple transmitters and multiple receivers often suffer from cross-interference among transmitters as well as among receivers. The cross-interference causes the fluctuation of the output power of the receiver and hard switching of the inverter on the transmitter. To avoid the cross-interference, controlling the amplitude and the phase of each transmitter current is an effective method. Therefore, this paper proposes a multiple-transmitter that can compensate for the cross-interference influence by implementing two controls. First, adopting the phase-shift control on the full-bridge inverter, the current amplitude is controlled to be constant. Second, applying the reactance control, each phase of the current is controlled to be in phase. In addition to the above operations, especially under a high-frequency operation, zero-voltage switching (ZVS) at a fixed operating frequency is essential for improving the power efficiency while not exceeding an allowable narrow bandwidth. Thus, the reactance control also works to ensure ZVS in all load conditions without adjusting the frequency. The RIC-WPT prototype with two transmitters and a single receiver is built to verify that the proposed multiple-transmitter can compensate for the cross-interference influence while achieving ZVS in different load conditions at a fixed operating frequency.

DOI： 10.1109/ECCE47101.2021.9595950

Autonomous Resonant Frequency Tuning Controller for Repeater Resonator in Resonant Inductive Coupling Wireless Power Transfer System

Akihiro Konishi, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

PROCEEDINGS OF 2021 IEEE 30TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE) 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The resonant inductive coupling wireless power transfer technique (RIC-WPT) is emerging as a promising wireless power transfer method for small mobile devices with comparatively high-power transfer capability and good efficiency. However, the performance of the RIC-WPT system is severely deteriorated by the resonant frequency detuning of the transmitter, repeater, and receiver resonators, which can be naturally caused by the manufacturing tolerance and the aging effect of these resonators. Particularly, the detuning of the repeater resonator tends to severely affect the performance due to its high-quality factor, which should be solved for practical application of RIC-WPT technology. This paper addresses this difficulty by proposing an autonomous resonant frequency tuning controller circuit for the repeater resonator. The controller tunes the resonant frequency of the repeater resonator to the operating frequency of the inverter, driving the transmitter, without an external power supply and wireless communication with the inverter controller, which restricts the freedom of the installation location and therefore preferably be avoided in the wireless power transfer system. The operating principles of the proposed controller were confirmed by the circuit simulator, supporting the feasibility of the proposed controller.

DOI： 10.1109/ISIE45552.2021.9576268

AC resistance Prediction of Litz Wire Planer Spiral Coil Based on Litz wire Loss Model

S. Kawahara, K. Umetani, E. Hiraki

23rd International Conference on Electrical Machines and Systems, ICEMS 2020 1541 - 1546 2020年11月

掲載種別：研究論文（国際会議プロシーディングス）

The Litz wire is utilized to wireless power transfer system and induction heating according to has small AC resistance in high frequency. Prediction of AC resistance of the Litz wire is important for design optimization of the Litz wire, hence the recent study has proposed analytical AC resistance prediction model of the Litz wire. However, verification in practical coils using the Litz wire is still insufficient. The purpose of this paper is to verify the prediction accuracy of AC resistance using a full analytical model in a practical coil. For practical coil, planer spiral coils are selected, and AC resistance of the planer spiral coil is calculated by combining with the loss model and the FEM analysis. As a result, the Litz wire loss model is found to well predict the measured AC resistance of the Litz wire planer spiral coil, supporting the appropriateness of the Litz wire loss model.

DOI： 10.23919/ICEMS50442.2020.9290802

Phase-current waveform for switched reluctance motors to eliminate input-current ripple and torque ripple in low-power propulsion below magnetic saturation

Takayuki Kusumi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

IET POWER ELECTRONICS 13 ( 15 ) 3351 - 3359 2020年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ENGINEERING TECHNOLOGY-IET

In recent decades, switched reluctance motors (SRMs) have been attracting increasing attention as a promising type of traction motors for electric vehicle propulsion, owing to their robust construction, elimination of permanent magnets. However, their phase inductance profile contains significant high-order harmonics, which generates input-current and torque ripples under SRM drive with the conventional square phase-current waveform. This study solves this problem by proposing a novel phase-current waveform in replacement of this square waveform. The proposed waveform is a predetermined waveform that can be stored as a look-up table in the inverter controller and can be magnified or attenuated to adjust the output torque, similarly as the conventional square waveform. Certainly, SRMs generally exhibit magnetic non-linearity due to magnetic saturation, which complicates the analysis. Therefore, the proposed waveform is analytically derived under the assumption that the magnetisation of the motor remains below the saturation level because vehicle propulsion tends to require a torque output far smaller than the maximum rating of the motor in normal vehicle travel. The proposed phase-current waveform is experimentally tested in comparison with the conventional square phase-current waveform. Consequently, the proposed waveform revealed smaller ripples in both the input-current and torque, supporting the effectiveness of the proposed phase-current waveform.

DOI： 10.1049/iet-pel.2019.1207

Simultaneous Tuning of Rotor Shape and Phase Current of Switched Reluctance Motors for Eliminating Input Current and Torque Ripples With Reduced Copper Loss

Takayuki Kusumi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 56 ( 6 ) 6384 - 6398 2020年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Switched reluctance motor (SRM) is recently emerging as a cost-effective but mechanically and thermally robust motor for vehicle propulsion. However, the conventional driving method of the SRM causes a large input current and torque ripples, both of which are scarcely acceptable for vehicle application. Recently, a promising driving method has been proposed that tunes the phase current to eliminate the input current and torque ripples simultaneously, although this method suffers from large copper loss when applied to the normal SRMs. To solve this problem, this article proposes simultaneous tuning of the rotor shape in combination with the recently proposed driving method, which includes only tuning of the phase current. Tuning of the rotor shape is targeted at minimizing the copper loss. Meanwhile, the stator structure is the same as the normal SRM design. The proposed approach was revealed to reduce the effective value of the phase current by 18% in simulation and by 23% in experiment compared with the recently proposed driving method, without increasing the input current and torque ripples. This result suggests the effectiveness of tuning both the rotor shape and the phase current for applying SRMs to vehicle propulsion.

DOI： 10.1109/TIA.2020.3015446

Strategy of Topology Selection Based on Quasi-Duality Between Series-Series and Series-Parallel Topologies of Resonant Inductive Coupling Wireless Power Transfer Systems

Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

IEEE TRANSACTIONS ON POWER ELECTRONICS 35 ( 7 ) 6785 - 6798 2020年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Series-series (SS) and series-parallel (SP) topologies are widely used in resonant inductive coupling wireless power transfer systems for various applications. However, the selection of an appropriate topology to achieve higher output power or higher efficiency is typically difficult because design optimization of the circuit parameters (e.g., characteristic impedance, load resistance, and mutual inductance) for each topology is generally separately discussed using different equivalent circuits with multiple resonance modes. Therefore, the purpose of this study involves proposing a simple strategy to select an appropriate topology. The proposed strategy is based on quasi-duality between the SS and SP topologies that are elucidated from the novel equivalent circuits derived using Lagrangian dynamics. Based on the quasi-duality, the output power and efficiency of the SP topology are calculated via the equivalent circuit of SS topology. Thus, the quasi-duality offers a simple comparison between the SS and SP topologies. The proposed strategy selects an appropriate topology by comparing only the equivalent ac load resistance, which is the ac resistance including the rectifying circuit and the load resistance, the characteristic impedance, and the ac load resistance that achieves the maximum efficiency ormaximum output power of the SS topology. Experiments verify the appropriateness and effectiveness of the proposed strategy.

DOI： 10.1109/TPEL.2019.2956732

Effects of Secondary Leakage Inductance on the LLC Resonant Converter

Mostafa Noah, Tomohide Shirakawa, Kazuhiro Umetani, Jun Imaoka, Masayoshi Yamamoto, Eiji Hiraki

IEEE TRANSACTIONS ON POWER ELECTRONICS 35 ( 1 ) 835 - 852 2020年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

It is quite often to utilize the transformer leakage inductance in the resonant tank of the LLC resonant converter to allow for a drastic reduction in the converter cost, weight, size, and volume. The effects of the secondary leakage inductance on the operation of the LLC resonant converter are not well discussed in the relevant literature, and it is the purpose of this paper to give an insight into these effects. The contribution of this paper lies in the following: first, highlighting that it is not always an accurate assumption to consider that the values of the primary and secondary leakage inductance are identical, specifically in asymmetric magnetic core structures. Second, it has been disclosed that the well-known coupling factor (k(12)) cannot properly express the unequalized leakage inductance distribution in the proposed asymmetric transformer. Therefore, the authors bring the primary coupling factor (k(1)) and secondary coupling factor (k(2)) into practice to appropriately express the unequalized leakage distribution on the primary and secondary windings, which can be controlled by the allocation of the relevant winding with respect to the air gap, utilizing the noise absorber, and changing the distance between the winding. Several transformer prototypes had been built and experimentally tested to validate these hypotheses. Third, it has been observed that the transformer voltage gain and efficiency can be improved when the transformer leakage inductance is concentrated on the secondary side to avoid the voltage drop inflicted by the relatively large value of the magnetizing current (i(m)), especially at the light load condition. Fourth, it has been reported that in a transformer structure with a concentrated value of leakage on the secondary side would decrease the resonant tank input impedance, vertically widen the voltage-gain curve of the converter, and eventually increase the frequency control bandwidth with respect to the load variation. Transformer prototypes had been constructed and tested in a 390 V/12 V-220 W LLC resonant converter to evaluate the proposed analysis.

DOI： 10.1109/TPEL.2019.2911093

Secondary-Side Center-Tapped Transformer Structure with One-Turn Secondary Coils Integrating Rectifier for Reducing Copper Loss of Forward Converter

Tomohide Shirakawa, Kazuhiro Umetani, Eiji Hiraki, Wilmar Martinez

2020 IEEE 29TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE) 1459 - 1465 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Secondary-side center-tapped transformer is a common transformer design of the high step-down forward converters owing to its effective reduction of the copper loss. Particularly, the extremely high step-down converters tend to have one-turn secondary coils to increase the winding turn ratio. However, due to the proximity effect in the terminal and the wire connecting the secondary coils and the rectifier, this design tends to suffer from significant deterioration of the copper loss reduction effect. To mitigate this problem, this paper proposes a novel transformer's secondary-side structure that integrates the one-turn secondary coils and the rectifier. The proposed transformer structure can mitigate the proximity effect in the secondary coils and the rectifier, thus suppressing the local concentration of the current distribution. Experiments revealed effective reduction of the copper loss, supporting the effectiveness of the proposed structure.

Competition-Based Learning of Power Converter Design Emulating Product Development Activity

Kazuhiro Umetani, Eiji Hiraki

IECON 2020: THE 46TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 3339 - 3344 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Power conversion technology is characterized by the comparatively small variation of circuit topologies. Because product competitiveness mainly lies in the performance quality as efficiency and low noise emission, the professional skills of this technology commonly require the ability to improve the quality under the restriction of the space, the material resource, and the cost. The conventional teaching method of the power conversion technology is mainly based on the lecture classes and the hands-on classes, which teach the fixed knowledge of the circuit operation. Therefore, this conventional method tends to be insufficient to cover the various practical strategies to improve the quality. To overcome this difficulty, this paper proposes application of the competition-based learning (CBL), in which teams of the students design their power converters and compete on the efficiency. For many professional engineers, competition among companies is the basic motivation to think of strategies to improve product competitiveness. Therefore, the CBL may be effective for teaching design strategies. For promotion of sharing the know-how, the proposed teaching method introduces the events, in which each team share its design strategies with other teams and improve its design based on the know-hows of other teams These events emulate the economic activity, in which a company investigates its competitors' products to extract the know-how. Along with the basic methodology of the proposed teaching method, this paper also reports the experience of a teaching course.

Optimization of Common Source Inductance and Gate-Drain Capacitance for Reducing Gate Voltage Fluctuation after Turn-off Transition

Yusuke Hatakenaka, Kazuhiro Umetani, Masataka Ishihara, Eiji Hiraki

2020 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 3155 - 3162 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Next-generation switching devices as GaN-FETs are recently emerging as promising switching devices capable of extremely high-speed switching. High-speed switching enables the high-frequency operation of the power converters, which can reduce the size of the passive components. However, highspeed switching can induce the resonance between the parasitic capacitance of the switching device and the parasitic inductance of the circuit board wiring, which appears as the gate voltage fluctuation at the switching. Particularly, GaN-FETs tend to have comparatively low gate threshold voltage and therefore are susceptible to the false turn-on, which is caused by the gate voltage fluctuation in the switching device just after the turn-off transition. For preventing this phenomenon, this paper analytically investigates the design requirement of these parasitic parameters to reduce the gate voltage fluctuation after the turn-off transition. As a result, the optimal ratio of the gate-drain capacitance and the common source inductance is elucidated to be the key to minimize the gate voltage fluctuation. The simulation and the experiment supported that the optimal design of this ratio can reduce the gate voltage fluctuation, supporting the usefulness of this novel insight for preventing the false turn-on.

Analysis and Prediction of AC Resistance of Litz Wire with Rectangular Cross-Section

Shota Kawahara, Kazuhiro Umetani, Eiji Hiraki

2020 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 3273 - 3279 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The Litz wire is widely utilized in recent high frequency switching regulators as a magnetic wire with small AC resistance. The AC resistance of the Litz wire is dependent on the twisting structure of the strands as well as the resultant cross-section geometry of the Litz wire. Therefore, optimization of the Litz wire is becoming important, although the numerical prediction of the AC resistance is difficult due to the complicated structure of the Litz wire. Certainly, a recent study has proposed an analytical AC resistance prediction method. However, this method cannot be applied to Litz wires with the rectangular cross-section, which is recently developed to improve the packing factor of the winding. This paper aims at extending this previous method to cover these Litz wires by partly utilizing a simple static magnetic field FEM analysis. The experiment revealed successful AC resistance prediction of the Litz wire with the rectangular cross-section.

Multiple-Transmitter Achieving Load-Independent Transmitter Current and Compensation of Cross-Interference Among Transmitters for Wide Charging Area Wireless Power Transfer Systems

Kodai Matsuura, Masataka Ishihara, Akihiro Konishi, Kazuhiro Umetani, Eiji Hiraki

2020 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 5474 - 5481 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Recently, a resonant inductive coupling wireless power transfer (RIC-WPT) system with multiple transmitters is emerging as a promising power supply method for household appliances, mobile devices, and wearable devices dispersedly placed in a wide area. However, the multiple-transmitter often suffers from an unstable operation of an inverter, feeding AC current to the transmitter coil, due to the cross-interference (i.e., cross-coupling) among the transmitters. When the cross-interference occurs, the inverter may not achieve high power factor and soft switching, which damages the power density and reliability of the multiple-transmitter. Therefore, this paper proposes a multiple-transmitter, including its controller, that can compensate for the effect of the cross-interference. In the proposed multiple-transmitter, each transmitter has a simple switching circuit that can automatically cancel the induced voltage due to the cross-interference with only simple control. Furthermore, the proposed multiple-transmitter also achieves a load-independent transmitter current by the control of the input voltage of the inverter, which results in a stable magnetic field regardless of load variation. Experiments verify the effectiveness and appropriateness of the proposed multiple-transmitter.

Homogenization of Current Distribution in Parallel Connection of Interleaved Winding Layers of High-Frequency Transformers by Optimizing Distance between Winding Layers

Ryo Murata, Tomohide Shirakawa, Kazuhiro Umetani, Eiji Hiraki, Hiroto Mizutani, Takaaki Takahara, Osamu Mori

2020 22ND EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'20 ECCE EUROPE) 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The windings of high-frequency high-current transformers are required to reduce the proximity effect loss. Therefore, the Litz wire in parallel connection of interleaved winding layers is usually used as the winding of transformers. However, this can cause unbalanced AC current distribution, hindering effective reduction of the copper loss. This paper solves this problem by optimizing the distance between the winding layers based on the analytical principle called the extremum co-energy principle. The transformers used in the experiment to verify this method consists of three parallel-connected primary winding and two parallel-connected secondary winding, PQ core, thin polypropylene sheets for adjusting the distance between the winding layers. As a result, the copper loss can be recused by homogenizing the AC current distribution, and the effectiveness of this method has been clarified by experiments.

Receiving-coil structure reducing stray AC resistance for resonant coupling wireless power transfer

Kazuhiro Umetani, Toru Honjo, Takahiro Koyama, Masataka Ishihara, Eiji Hiraki

IET POWER ELECTRONICS 12 ( 9 ) 2338 - 2344 2019年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ENGINEERING TECHNOLOGY-IET

Resonant inductive coupling wireless power transfer is widely known to be a possible convenient power supply method for the small mobile apparatus. However, the limited receiving-coil size tends to lower the efficiency and limit the output power owing to the small mutual inductance and comparatively large stray alternating current (AC) resistance of the receiving-coil. This study mitigates this issue by proposing a novel receiving-coil structure. This proposed structure comprises a coil and a drum core with a thin axis. The coil is wound on the axis to form a single winding layer. The proposed structure can reduce stray AC resistance by suppressing the proximity effect and reducing the wire length without deteriorating the mutual inductance significantly. Therefore, better efficiency and larger output power can be achieved. Simulations and experiments were performed to verify the proposed structure. Consequently, both simulations and experiments supported the reduction in AC resistance compared to the conventional structure. Furthermore, the experiment revealed improvements by the proposed structure in both efficiency and output power. These results support the effectiveness of the proposed structure for wireless power transfer to small mobile apparatus.

DOI： 10.1049/iet-pel.2018.5358

Volume Reduction Effect of Thinly Extended Core Structure for Transformer in Isolated DC-DC Converter 査読

R. Murata, T. Shirakawa, K. Umetani, E. Hiraki

ICPE 2019 - ECCE Asia - 10th International Conference on Power Electronics - ECCE Asia 2132 - 2138 2019年5月

掲載種別：研究論文（国際会議プロシーディングス）

© 2019 The Korean Institute of Power Electronics (KIPE). The high-frequency transformers used for isolated DC-DC converters tend to have large volume compared with the other components. Therefore, increasing the power density of the transformer is indispensable for increasing the power density of the DC-DC converter. Reducing the dead space of the transformer is one of the effective solutions. It is well-known that the thinly extended core structure reduces the dead space around the transformer formed by the windings protruding to the outside of the core. However, it has not been clarified how much the thinly extended core structure affects the reducing power loss of the transformer. In this paper, the effect of introducing the thinly extended core structure into the transformer is quantified by the optimization of the convertible design parameters of the transformer with systematic round-robin calculation. The result revealed the volume reduction effect by the thinly extended core was greater than the simply dead space reduction effect.

Prevention of Oscillatory False Triggering of GaN-FETs by Balancing Gate-Drain Capacitance and Common-Source Inductance

Kazuhiro Umetani, Ryunosuke Matsumoto, Eiji Hiraki

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 55 ( 1 ) 610 - 619 2019年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Gallium-nitride-field-effect transistors (GaN-FETs) are promising switching devices with fast switching capability. However, they commonly have low gate threshold voltage, suffering from susceptibility to the false triggering. Particularly, the oscillatory false triggering, i.e., a self-sustaining repetitive false triggering, can occur after a fast switching, which is a severe obstacle for industrial applications. The purpose of this paper is to elucidate the design instruction for preventing this phenomenon. The oscillatory false triggering is known to be caused by the parasitic oscillator circuit formed of a GaN-FET, its parasitic capacitance and the parasitic inductance of the wiring. This paper analyzed the nonoscillatory condition of this oscillator. The result revealed an appropriate ratio between the gate-drain capacitance and the common-source inductance is a key to prevent the oscillatory false triggering. Experiment successfully verified this analysis result, supporting the effectiveness of the appropriate design of this ratio for preventing the oscillatory false triggering.

DOI： 10.1109/TIA.2018.2868272

Automatic Active Compensation Method of Cross-Coupling in Multiple-receiver Resonant Inductive Coupling Wireless Power Transfer Systems

Masataka Ishihara, Keita Fujiki, Kazuhiro Umetani, Eiji Hiraki

2019 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 4584 - 4591 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The ability to charge to multiple receivers simultaneously with a single transmitter is one of the advantages of resonant inductive coupling wireless power transfer (RICWPT) technologies. However, in multiple-receiver RIC-WPT systems, each receiver often suffers from the magnetic coupling among receivers, i.e., cross-coupling. The cross-coupling not only complicates the control of the receivers but also significantly decreases the output power of each receiver. Hence, the purpose of this paper is to propose a compensation method of the influence due to the cross-coupling. To achieve this purpose, we first analyze the requirement to compensate for the influence of the cross-coupling. As a result, we reveal that it is necessary to control the phase of the current in all the receiver to be orthogonal to the phase of the transmitter current. Then, we propose the method to adjust the current phase of each receiver automatically to the desired phase by using only the phase information of the transmitter current, which results in the full compensation of the influence due to the cross-coupling. Furthermore, the proposed method also compensates for the influence of a detuning of the resonant frequency of each receiver due to the natural tolerance. Experiments of a two-receiver RIC-WPT system successfully verify the effectiveness of the proposed method.

Resonant Frequency Tuning System for Repeater Resonator of Resonant Inductive Coupling Wireless Power Transfer

Akihiro Konishi, Keita Fujiki, Kazuhiro Umetani, Eiji Hiraki

2019 21ST EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE '19 ECCE EUROPE) 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The resonant inductive coupling wireless power transfer (RTC-WPT) is a promising technique of the wireless power transfer with comparatively large power and high efficiency. However, the performance of RTC-WPT system is generally highly dependent on the fine adjustment of the resonant frequency between the transmitter, receiver, and repeater resonators, although the natural tolerance of the capacitor and inductance of the coil may easily lead to the significant detuning of the resonant frequency. Particularly, the repeater resonator is the key item that can improve the power transfer to a distantly located receiver resonator. However, the repeater resonator tends to have a high quality-factor; and therefore, its performance can be easily deteriorated by the detuning of the resonant frequency. The purpose of this paper is to propose a simple automatic resonant frequency tuning system for the repeater resonator as a remedy for the performance deterioration due to the resonant frequency detuning. The operation of the automatic resonant frequency tuning system was experimentally tested using the prototype wireless power transfer system. The result exhibited robust power transfer capability regardless of the natural tolerance of the resonant frequency.

Core Loss Modeling Based on Equivalent Circuit for Switched Reluctance Motors

Takayuki Kusumi, Kosuke Kobayashi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

2019 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL TECHNOLOGY (ICIT) 1743 - 1748 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

To estimate the core loss in SRMs, core loss estimation by equivalent circuit is preferable especially in the EV development because of its simple calculation. However, previously proposed models may limit applicable operating condition. These models refer instantaneous value, whereas hysteresis loop is a key factor to estimate core loss and the hysteresis loop directly associates with the history of magnetic flux. This paper focuses on the relation between the width of hysteresis loop and the peak to peak value of magnetic flux because the relation directly expresses the core loss. Therefore, the purpose of this paper is to propose a novel core loss model for equivalent circuit which estimates core loss in SRMs. This paper refers the peak to peak value of magnetic flux linkage and electrical angle. Along with the theoretical formulation of the model, this paper presents the model construction method. As a result, the proposed model successfully estimated core loss.

DOI： 10.1109/ICIT.2019.8754931

Analytical Derivation of Phase Current Waveform Eliminating Torque Ripple and Input Current Ripple of Switched Reluctance Motors under Magnetically Saturated Operation

Takayuki Kusumi, Kosuke Kobayashi, Kazuhiro Umetani, Eiji Hiraki

2019 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 6540 - 6547 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Switched reluctance motors (SRMs) is beneficial in excellent cost-effectiveness and high thermal tolerance owing to their simple mechanical construction free from permanent magnets. Nevertheless, application of SRMs to vehicular propulsion is often hindered by their comparatively large input current ripple and torque ripple. For mitigating the problem, the previous study has proposed a phase current waveform that eliminates both of these ripples under the magnetization below the magnetic saturation. However, this previous technique still suffers from significant torque and input current ripples at large output torque, which tends to cause the magnetic saturation. This paper proposes an improved phase current waveform that eliminates these ripples even at large output torque. This waveform was derived analytically based on the nonlinear magnetic model of the SRM. The proposed phase current waveform was successfully verified by the experiment, suggesting the usefulness of the proposed technique for applying SRMs to vehicular propulsion.

Experimental Verification of Impedance Matching Method for Repeater to Improve Spatial Freedom of 6.78 MHz Resonant Inductive Coupling Wireless Power Transfer Systems

Keita Fujiki, Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

2019 21ST EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE '19 ECCE EUROPE) 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Placing a repeater, which relays the magnetic field from the transmitter to the receiver, is promising as a method to increase the spatial freedom of resonant inductive coupling wireless power transfer systems (RTC-WPT) working at 6.78MHz. However, the capability of the repeater is often affected by a frequency splitting phenomenon. When this phenomenon occurs, the resonance in the repeater becomes sufficiently small at a fixed operating frequency and make it difficult to improve the spatial freedom. To solve this problem, we apply an impedance matching method using simple switching circuits to the 6.78 RTC-WPT system with the repeater. Then we carry out experiments to verify the effectiveness of the impedance matching method. The experimental results show that the repeater improves the spatial freedom of the 6.78 MHz RTC-WPT regardless of the frequency splitting phenomenon.

Simple Fully Analytical Copper Loss Model of Litz Wire Made of Strands Twisted in Multiple Levels

Kazuhiro Umetani, Jesus Acero, Hector Sarnago, Oscar Lucia, Eiji Hiraki

THIRTY-FOURTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2019) 1257 - 1264 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The Litz wire has been widely utilized as a wire with a low copper loss under high-frequency operation. However, design optimization of the Litz wire is difficult because this wire generally has a complicated structure of thin strands twisted in multiple levels, which hinders both of the analytical and numerical prediction of the copper loss. To overcome this issue, recent studies have proposed the analytical models of the copper loss in the bundle of twisted strands, which is the basic components constituting the Litz wire. This paper constructs a simple analytical copper loss model of the Litz wire based on these preceding insights. In addition to these insights, the proposed model further considers the effect of the inclination angle of the strands to the Litz wire on the proximity effect loss. The proposed model was tested in comparison with the experimentally measured AC resistance of commercially available Litz wires. As a result, the predicted AC resistance showed good agreement with the measured ac resistance, suggesting the effectiveness of the proposed model.

Effects of Secondary Leakage Inductance on the LLC Resonant Converter-Part I: Transformer Voltage Gain and Efficiency

Mostafa Noah, Tomohide Shirakawa, Kazuhiro Umetani, Jun Imaoka, Masayoshi Yamamoto, Eiji Hiraki

THIRTY-FOURTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2019) 780 - 786 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Minimizing the transformer magnetizing inductance is essential for the soft switching operation of the LLC resonant converter, despite the fact that it results in higher values of magnetizing current, which deteriorates the converter efficiency. Furthermore, it is a well-known practice to utilize the transformer leakage as an inductive component in the resonant tank to improve the power destiny. This paper reveals that the transformer voltage gain can be improved when the transformer leakage inductance in concentrated on the secondary side to avoid the voltage drop inflicted by the relatively large value of the magnetizing current (i.), especially at light load condition. The theoretical discussion relies on the asymmetry of the EI core by placing the secondary winding in a close contact with the magnetic core and placing the primary winding in the vicinity of the air gap. Moreover, noise absorber had been utilized to control the leakage inductance value. The proposed transformer design maximizes the value of the secondary leakage inductance and minimizes the primary leakage inductance. Alongside with the theoretical discussion, experimental tests had been conducted to evaluate the proposed method using a 390V-12V, 220W LLC resonant converter.

Effects of Secondary Leakage Inductance on the LLC Resonant Converter-Part II: Frequency Control Bandwidth with respect to Load Variation

Mostafa Noah, Tomohide Shirakawa, Kazuhiro Umetani, Jun Imaoka, Masayoshi Yamamoto, Eiji Hiraki

THIRTY-FOURTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2019) 1408 - 1414 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Resonant converters rely on a precise knowledge of leakage inductance of the equipped transformers. Resonant circuit topologies such as LLC usually utilize the transformer leakage as an inductive component in the resonant tank, allowing for a drastic reduction in the converter weight, size and volume. The existence of the secondary leakage inductance affects the whole operation of the LLC resonant converter. This paper reveals that placing the secondary winding near the air gap would increase the resonant tank input impedance, vertically shrink the voltage-gain curve of the converter, and consequently minimize the frequency range (i.e frequency bandwidth with respect to load variation). On contrary, placing the secondary winding in a close contact with the magnetic core would decrease the resonant tank input impedance, vertically stretches the voltage-gain curve of the converter, and widen the frequency variation range. It has been reported that the winding location with respect to the air gap has an impact on the leakage inductance value. In other words, placing the secondary winding in a close contact with the magnetic core (zero mmf position) would maximize the leakage energy storage originated from the secondary winding, and hence maximize the secondary leakage inductance and vice versa. The theoretical discussion is presented which is merely based on Ampere's law and Dowell's model. Furthermore, transformer prototypes had been constructed and tested in a 390V/12V-220W LLC converter prototype to evaluate the proposed analysis.

Optimal Winding Layer Allocation for Minimizing Copper Loss of Secondary-Side Center-Tapped Forward Transformer with Parallel-Connected Secondary Windings

Tomohide Shirakawa, Kazuhiro Umetani, Eiji Hiraki, Yuki Itoh, Takashi Hyodo

2019 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 6206 - 6213 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Secondary-side center-tapped transformers are widely utilized for high step-down forward DC-DC converters. For reducing the copper loss, optimization of the winding layer allocation can be a promising approach. However, the optimal allocation pattern has been difficult to be elucidated, particularly if the winding is formed of parallel-connected winding layers or carries the AC and DC current as in a center-tapped winding. This difficulty is addressed in this paper by proposing a copper loss analysis method applicable to parallel-connected winding layers and a center-tapped winding. The proposed analysis method utilizes the Dowell method in combination with the extremum co-energy principle, which has been recently proposed to analyze the current distribution in parallel-connected winding layers. As an example, this paper analyzes the center-tapped transformer each secondary winding of which is made of two parallel-connected winding layers. The optimal winding layer allocation pattern was elucidated by comparing the copper loss among six possible winding layer allocation patterns. Appropriateness of the analysis was verified by simulation, suggesting the effectiveness of the proposed method and the importance of optimizing winding layer allocation in the forward transformer design.

Axial Heating Coil Structure for Reducing Magnetic Levitation Force of All-Metal Type Induction Cookers

Koki Kamaeguchi, Kazuhiro Umetani, Eiji Hiraki

2019 8TH INTERNATIONAL CONFERENCE ON RENEWABLE ENERGY RESEARCH AND APPLICATIONS (ICRERA 2019) 793 - 798 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

All-metal type induction cookers are utilized to heating up the non-iron pans such as the copper and aluminum pans. These cookers are designed to drive the heating coil with extremely high frequency and large AC current. However, the high-frequency large current drive tends to generate a large electromagnetic force which has the direction levitating the pans to be heated and damages the safeties of the induction cooking by moving the hot pans. The purpose of this study is to propose a novel heating coil structure that can reduce the levitation force. The proposed structure coil is similar to the axial gap induction machine. This coil structure generates the electromagnetic force in parallel to the coil surface rather than perpendicular to the surface, thus mitigating the levitation force. In addition, a novel AC power supply is proposed to drive the proposed structure coil. The experiment revealed a successful reduction of the levitation force by approximately 20% compared to the conventional coil structure, supporting the effectiveness of the proposed coil structure.

Verification of Device Model by Measuring Capacitance and Static Characteristics for Predicting Switching Waveform

Kengo Koki, Masahiko Yoshioka, Kazuhiro Umetani, Eiji Hiraki

2019 8TH INTERNATIONAL CONFERENCE ON RENEWABLE ENERGY RESEARCH AND APPLICATIONS (ICRERA 2019) 786 - 792 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Recently, as the miniaturization and densification of the power conversion circuit, switching frequency has been increased. To accomplish the densification, it is essential to predict the losses that occur in each part for the optimization of electric components. However, switching loss which needs to consider nonlinear characteristics are difficult to predict. As a solution, considering the dependence of the gate-drain capacitance on gate-source voltage may improve the prediction accuracy of switching loss. The purpose of this study is to evaluate the improvement of prediction accuracy by considering it. First, to construct the simulation model, the wiring parameter in the circuit, static characteristics and the parasitic capacitance of the device was measured. Next, the device model provided by the manufacturer to use in the simulation was adjusted. Also, the characteristics of the gate-drain capacitance on the gate-source voltage were obtained from two types of measurement circuits. As a result, it was verified that the difference which occurred at the rise of the drain-source voltage at the turn-off tended to decrease and prediction accuracy of the turn-off loss was improved by considering the characteristics of the gate-drain capacitance on the gate-source voltage. Therefore, we concluded that this consideration has the ability to the improvement of turn-off waveforms.

Impedance Matching to Maximize Induced Current in Repeater of Resonant Inductive Coupling Wireless Power Transfer Systems

Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

2018 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 6194 - 6201 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Intermediate resonators (repeaters) of resonant inductive coupling wireless power transfer systems can improve the transmission distance as well as the output power. However, frequency bandwidths in which the repeater can operate effectively are very narrow because the repeater usually has a high quality-factor. Furthermore, these frequency bandwidths shift for the following two factors. The first factor is the intensity of the magnetic coupling between the repeater and the other resonator. The second factor is the variation in the natural resonance frequency of the resonators due to a production error, temperature characteristic, and aging degradation. Therefore, the repeater is not practical because the repeater requires accurate adjusting of the circuit parameters every time according to the various conditions. To address this problem, we propose an impedance matching method for the repeater. The proposed method can maximize the induced current in the repeater in wide frequency bandwidth regardless of the variations in the intensity of the magnetic coupling and the natural resonance frequency. Therefore, the proposed method can realize the repeater which can stably improve the performance of the wireless power transfer. Experiment and simulation successfully verified the effectiveness of the proposed method as well as the appropriateness of the theoretical analysis.

Application of Automatic Resonant Frequency Tuning Circuit to Induction Heating System

Koki Kamaeguchi, Kazuhiro Umetani, Eiji Hiraki

2018 20TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'18 ECCE EUROPE) 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Induction heating is the technique that heats the conductive material by high frequency large AC magnetic field. For efficient generation of the AC magnetic field, induction heating technique commonly utilizes the resonance between the heating coil and the resonating capacitor. The resonance is generally excited by applying the AC voltage of the resonant frequency. However, the resonant frequency is unstable because this frequency is susceptible to the disposition of the material to be heated. As a result, high efficiency high power induction heating system often suffers from unstable operation. This paper addresses this problem by proposing application of a simple automatic resonant frequency tuning circuit to the induction heating. This circuit can automatically achieve equivalent adjustment of the resonance frequency at the operating frequency without special control or the circuit sensing. In addition, this paper elucidated the control method of this tuning circuit to achieve the soft-switching operation in both of the inverter that drives the heating coil and the tuning circuit itself. The experiment revealed successful stabilization of the resonant frequency as well as satisfaction of the soft-switching condition both of the inverter and the tuning circuit, supporting effectiveness of the tuning circuit for induction heating.

High-frequency Self-Driven Synchronous Rectifier Controller for WPT Systems

Akihiro Konishi, Kazuhiro Umetani, Eiji Hiraki

2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA) 1602 - 1609 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Resonant inductive coupling wireless power transfer (RIC-WPT) is the promising wireless power supply method to mobile applications. It is well-known that the efficiency and the power transfer capability of RIC-WPT systems deeply depend on the quality factor of the receiver-side resonator, which tends to decline by the conduction loss at rectifying diodes. Therefore, the synchronous rectification is one of the effective solutions. However, the unique characteristics of RIC-WPT, that is the weak magnetic coupling between the transmitter-side and the receiver-side resonator, tend to make the introduction of the synchronous rectification difficult. In order to address this issue, this paper newly proposes a self-driven synchronous rectifier controller suitable for RIC-WPT. This synchronous rectifier controller consists of basic analog elements and gate drivers, and no additional power supply is necessary for driving itself. In addition, the controller doesn't require any information from the transmitter-side resonator. Experiments successfully verified the operating principle as well as the efficiency improvement and clarified the usefulness of the synchronous rectifier with proposed controller for practical application of RIC-WPT.

Improving Robustness Against Variation in Resonance Frequency for Repeater of Resonant Inductive Coupling Wireless Power Transfer Systems

Masataka Ishihara, Shoma Ohata, Keita Fujiki, Kazuhiro Umetani, Eiji Hiraki

2018 20TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'18 ECCE EUROPE) 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Intermediate resonators (repeaters) for resonant inductive coupling wireless power transfer have been widely studied as a method of improving not only the transmission distance but also the output power. For the repeater to operate effectively, it is needed to induce a large current in the repeater to enhance the magnetic field far from a transmitting resonator. However, it is often difficult to induce a large current in the repeater due to frequency splitting phenomenon. This phenomenon easily occurs when the resonator having high quality factor such as the repeater is used. The frequency characteristic of the induced current in the repeater has multiple peaks when the frequency splitting phenomenon occurs. In addition, these multiple peaks shift according to slight variation in the parameters of the coil and the capacitor that constitute the resonator. This slight variation is easily caused by production error, temperature characteristic, and aging degradation of the coil and the capacitor. The induced current in the repeater is significantly decreased by the slight variation in the parameters, namely, the slight variation in the resonance frequency. Therefore, the repeater has low robustness against variation in the resonance frequency. To address these difficulties, we apply an auxiliary circuit to the repeater. The auxiliary circuit can dynamically adjust a phase of the induced current in the repeater, namely, the resonance frequency without complicated control. As a result, a large induced current can be maintained even if the frequencies corresponding to the peaks shift. Consequently, we can provide the repeater having a stable characteristic against the variation in the resonance frequency. The effectiveness of the repeater applied the auxiliary circuit and the appropriateness of analysis results are supported with simulation and experimental results.

Soft-Switching Control Circuit Based on Traveling and Reflected Waves for High -Frequency Resonant Inverter Applicable to Capacitive Load Impedance

Aoi Oyane, Koji Itakura, Kazuhiro Umetani, Eiji Hiraki, Tatsuya Ikenari, Shingo Kawano

IECON 2018 - 44TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 3051 - 3056 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Resonant inverters are widely utilized to generate high-frequency high voltage AC power for the power supply to the plasma generator. These inverters commonly require the load impedance to be inductive for achieving soft-switching operation. However, the impedance often fluctuates to be momentarily capacitive due to the unstable state of the plasma, thus causing enormous switching loss and possibly destroying the inverters. This paper addresses this difficulty by using a recently-proposed resonant inverter that can achieve soft-switching operation under the capacitive load impedance. For this purpose, this paper proposes a novel soft-switching controller for applying this inverter for plasma generator application. The proposed controller observes the load impedance and controls the resonant inverter according to the impedance value. Because of the highfrequency AC power supply to the plasma generator, the voltage and current measurement are difficult for estimation of the load impedance. Therefore, the proposed controller estimates the load impedance based on traveling and reflected wave measurement. The experiment revealed successful control of the inverter according to the load impedance, suggesting high feasibility for applying the inverter to the plasma generator.

Extremum Co-Energy Principle for Analyzing AC Current Distribution in Parallel-Connected Wires of High-Frequency Power Inductors

Tomohide Shirakawa, Genki Yamasaki, Kazuhiro Umetani, Eiji Hiraki

IEEJ JOURNAL OF INDUSTRY APPLICATIONS 7 ( 1 ) 35 - 42 2018年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ELECTRICAL ENGINEERS JAPAN

Inductor winding is often comprised of parallel-connected wires to suppress copper loss. However, in high-frequency inductors, the proximity effect can cause concentrated AC current distribution, hindering the suppression of the copper loss. Therefore, optimization of the physical inductor structure requires predicting the AC current distribution caused by the proximity effect. Certainly, simulators have been commonly employed for predicting the AC current distribution. However, simple analytical methods are also required for efficient design or invention of inductor structures that have more uniform AC current distribution among the parallel-connected wires. The paper proposes a novel simple analysis method for AC current distribution in parallel-connected wires of high-frequency inductors. The proposed method is based on a novel insight that AC current is distributed to give an extremum of the magnetic co-energy contributed by the AC flux under the given total AC current. Analysis of basic inductor structures revealed that the proposed method can derive the AC current distribution by straightforward calculation. In addition, experiments supported the analysis results. Consequently, the proposed method is suggested to be promising for developing inductor structures with less copper loss.

DOI： 10.1541/ieejjia.7.35

Improved Thin Heating Coil Structure of Copper Foil Feasible for Induction Cookers

Kazuhiro Umetani, Tomohiro Mishima, Eiji Hiraki, Takayuki Hirokawa, Makoto Imai, Hideki Sadakata

IECON 2018 - 44TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 3503 - 3508 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Litz wire is widely utilized for heating coils of the induction cookers to suppress the proximity effect. However, low space factor of the Litz wire often significantly increases the heating coil height, which may be an obstacle of wide-spread of the induction cookers. In order to overcome this problem, a preceding study has proposed a heating coil structure of the copper foil, which suppresses the proximity effect without using the Litz wire. The preceding study has proven effective suppression of the proximity effect, when the material to be heated is placed to cover the heating coil. However, this heating coil structure still suffers from large AC resistance, when the material to be heated does not exist or partially covers the heating coil. Furthermore, the ferrite walls, installed to suppress the proximity effect, need larger height than the coil, hindering effective reduction of the total heating coil height. The purpose of this paper is to propose an improved heating coil structure. The proposed heating coil structure further incorporates a thin layer of low-permeability soft-magnetic material covering the top of the coil. This layer enables elimination of the proximity effect regardless of the existence or the disposition of the material to be heated. Furthermore, this layer enables the ferrite walls to have the same height as the coil, thus further reducing the total heating coil height. The FEM based simulation was carried out to verify the operating principle of this structure. The result supported reduction of the heating coil height and effective suppression of the AC resistance regardless of the existence and the disposition of the material to be heated.

Design Optimization Method for the Load Impedance to Maximize the Output Power in Dual Transmitting Resonator Wireless Power Transfer System

Takahiro Koyama, Kazuhiro Umetani, Eiji Hiraki

IEEJ JOURNAL OF INDUSTRY APPLICATIONS 7 ( 1 ) 49 - 55 2018年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ELECTRICAL ENGINEERS JAPAN

Recently, the dual transmitting resonator wireless power transfer system (DTR-WPT) has been proposed as a promising technique for the power supply of mobile apparatus. Although this technique has been reported to be effective for increasing the output power as well as for covering a wide area during wireless power transfer, the complicated magnetic coupling among two transmitting resonators and one receiving resonator makes it difficult to develop practical design optimization methods, thus hindering practical applications of this technique. The purpose of this paper is to propose a design optimization method for the load impedance of DTR-WPT. This method is derived based on a novel simple equivalent circuit model of the DTR-WPT. The optimum impedance derived using this method as well as the appropriateness of the equivalent circuit were verified experimentally, thus validating usefulness of the proposed method for the practical application of DTR-WPT.

DOI： 10.1541/ieejjia.7.49

Theoretical Derivation of Phase Current Profile for Switched Reluctance Motors to Suppress Radial Force Ripple and Torque Ripple

Takayuki Kusumi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

2018 IEEE 27TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE) 1037 - 1042 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Switched reluctance motors (SRMs) are promising for propulsion motors of electric vehicles (EVs) because of their robust mechanical construction and cost effectiveness. However, practical application of SRMs to vehicular propulsion is hindered by comparatively large torque ripple and radial force ripple, which cause noise vibration and acoustic noise. Previous studies have proposed phase current profiles which suppress both ripples. However, in the derivation process of phase current, these previous studies need numerical calculation hindering the EV development speed. The purpose of this paper is to propose a novel phase current profile to suppress both the torque ripple and the radial force ripple of SRMs without numerical calculation. The profile can be straightforwardly calculated using a simple analytical model of the SRMs. In addition, the profile can be determined for any reluctance profiles of actual SRMs. Experiment was carried out to verify the proposed method. The result supported suppression of the torque ripple and the acoustic noise by the proposed method.

Rotor Configuration Which Reduces Copper Loss of Switched Reluctance Motors With Suppression of Torque Ripple and Input Current Ripple

Takayuki Kusumi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

2018 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 6097 - 6103 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Switched reluctance motors (SRMs) are attractive motors for electric vehicle propulsion because of their cost-effectiveness or robust structures. However, SRMs suffer from input current ripple and torque ripple. The authors have proposed derivation method of phase current profile which suppresses input current ripple and torque ripple and experimentally verified the suppression of both ripples. However, the rms value of derived phase current was much greater than square wave current, which is implemented widely, and increased copper loss. For the EV application, the rms value should be reduced. To break through the issue, the author addressed the characteristic that phase current profiles are shaped based on each reluctance profile, which is shaped by motor configuration, and noticed that phase current profile with low rms value may be derived by a novel rotor configuration. Therefore, this paper proposes a novel rotor configuration which can reduce the copper loss. The proposed rotor configuration is designed to satisfy the reluctance profile which is derived by previously proposed derivation method of phase current. This paper also presents the experiment for the evaluation of the reduction of copper loss.

Verification of the Reduction of the Copper Loss by the Thin Coil Structure for Induction Cookers

Morimasa Hataya, Koki Kamaeguchi, Eiji Hiraki, Kazuhiro Umetani, Takayuki Hirokawa, Makoto Imai, Hideki Sadakata

2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA) 410 - 415 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Litz wire is commonly employed as the heating coil of induction cookers. In order to realize further low cost and profile, the solid wire with simple construction and high space factor is required. However, the solid wire is may suffer from the large copper loss increased by the skin and proximity effect. Then, the previous study proposed the novel coil structure, which can suppress these effects, only by the FEM simulation. Therefore, the purpose of this paper is to verify this structure experimentally in comparison with the Litz wire coil. The result revealed that the proposed structure can have similar AC resistance and the similar height with the same surface area and the same number of turns. Moreover, the experimental result showed a possibility to further height reduction by optimization of the magnetic and winding isolation design. Consequently, the experiment supported practical effectiveness of the proposed structure for induction heating.

Feasibility Study of Fractal-Fin Heat Sink for Improving Cooling Performance of Switching Power Converters

Shogo Ikegami, Kazuhiro Umetani, Eiji Hiraki, Satoshi Sakai, Satoshi Higashino

2018 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC) 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Recent progress of the semiconductor switching devices enabled the high-frequency design of the switching power converters, which successfully led to the miniaturization of the circuit elements. However, the heat sink has scarcely been miniaturized during past decades. Now, the heat sinks are one of the major obstacles that hinder further size reduction of the switching power converters. Conventionally, the heat sinks are designed to have a number of flat aluminum fins extending from the aluminum base. However, these flat fins tend to make the laminar airflow passing through the fins. This laminar airflow keeps the air contacting the fin surface to remain on the surface. As a result, the fin surface is covered with the air already heated in the upstream and the fresh open air is prevented from contacting with the fin surface, thus deteriorating the cooling performance of the heat sinks. To overcome this issue, this paper proposes a heat sink structure with a novel fin geometry. The proposed fin geometry incorporates two sizes of the louvers, which are disposed to form a fractal-like pattern. These louvers are intended to break the laminar flow on the fin surface, thus promoting the mixing of the air to improve the cooling performance. FEM simulation of the heat transfer was carried out to verify this concept. The result showed improvement in the heat transfer coefficient, implying the effectiveness of the proposed structure for miniaturization of the heat sink.

Automatic Resonance Frequency Tuning Method for Repeater in Resonant Inductive Coupling Wireless Power Transfer Systems

Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA) 1610 - 1616 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Intermediate resonator (repeater) in resonant inductive coupling wireless power transfer (RIC-WPT) systems can increase the transmission distance between the transmitting and receiving coils. The induced current in the repeater is easily affected by the frequency splitting phenomenon because the quality factor (Q-factor) of the repeater is generally as high as several hundreds. If this phenomenon occurs, induction of large current is often difficult in the repeater because the one peak characteristic of the induced current is no longer expected and the single peak of resonance splits into multiple peaks which shift the resonant frequency corresponding to the circuit parameters. In this paper, we approach this difficulty by applying an auxiliary circuit to the RIC-WPT system with the repeater. As a result, under the fixed operating frequency, the induced current in the repeater can be kept large even if the frequency splitting phenomenon occurs. The effectiveness of proposed system was supported by the simulation and experiment.

Straightforward Measurement Method of Common Source Inductance for Fast Switching Semiconductor Devices Mounted on Board

Kazuhiro Umetani, Kyota Aikawa, Eiji Hiraki

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 64 ( 10 ) 8258 - 8267 2017年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Recent progress of widebandgap semiconductor switching devices enabled extremely high-frequency operation of power converters owing to their ultrafast switching capability. Fast switching may cause large switching noise at the common source inductance, which may increase the switching loss and lead to false triggering. Therefore, measurement of the common source inductance is often intensely required in practical design of fast switching power converters. However, measurement of the common source inductance is difficult, because 1) the wiring path hidden beneath the molded package significantly contributes to this inductance, 2) the mutual inductance between the gating circuit and the power circuit also contributes to this inductance, and 3) this inductance cannot be defined as the stray inductance of a loop wiring path. These difficulties are addressed in this paper by proposing a novel measurement method of the common source inductance. The proposed method is applicable to already-mounted power circuits. In addition, the proposed method offers a straightforward measurement procedure with common instruments, such as a signal generator, an oscilloscope, and voltage and current probes. Along with the measurement principle, this paper also presents an experiment to evaluate the proposed method.

DOI： 10.1109/TIE.2017.2694411

Novel receiving coil structure for improving efficiency and power transfer capability of resonant inductive coupling wireless power transfer 査読

T. Honjo, T. Koyama, K. Umetani, E. Hiraki

19th International Conference on Electrical Machines and Systems, ICEMS 2016 2017年1月

掲載種別：研究論文（国際会議プロシーディングス）

© 2016 The Institute of Electrical Engineers of Japan. Resonant inductive coupling wireless power transfer (RIC-WPT) is attractive as a convenient power supply method to small mobile apparatus. However, limited size of the receiving coil can limit the efficiency and the power transfer capability. This paper addresses this difficulty by proposing a novel receiving coil structure. The proposed structure has a coil wound on a drum core with a thin axis. The top and the bottom of the drum core has large surface area to effectively collect the magnetic flux for large mutual inductance. In addition, the thin axis can reduce the wire length, thus reducing the parasitic AC resistance. The AC resistance is further reduced by suppressing the proximity effect. Simulation supported probable improvement in the efficiency as well as the power transfer capability. In addition, experiment verified that the proposed structure improved the efficiency by 66% and the power transfer capability by 109%.

Novel thin heating coil structure with reduced copper loss for high frequency induction cookers 査読

M. Hataya, Y. Oka, K. Umetani, E. Hiraki, T. Hirokawa, M. Imai

19th International Conference on Electrical Machines and Systems, ICEMS 2016 2017年1月

掲載種別：研究論文（国際会議プロシーディングス）

© 2016 The Institute of Electrical Engineers of Japan. Litz wire has been widely utilized for heating coils of high frequency induction cookers. However, these coils often suffer from large winding height due to low space factor of Litz wire. Certainly, rectangular wire may reduce the winding height of the coil owing to its high space factor. However, the rectangular wire tends to suffer from large copper loss caused by the skin effect and the proximity effect. In the conventional coil structure of the rectangular wire, these effects cause concentrated AC current distribution, which leads to excessive copper loss. This paper addresses this issue by proposing a novel heating coil structure of the rectangular wire that can homogenize the AC current distribution. This paper also presents the simulation results that successfully verified the effectiveness of the proposed structure.

Optimization of the Balance between the Gate-Drain Capacitance and the Common Source Inductance for Preventing the Oscillatory False Triggering of Fast Switching GaN-FETs

Rynosuke Matsumoto, Kazuhiro Umetani, Eiji Hiraki

2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 405 - 412 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

GaN-FETs are attractive switching devices for their fast switching capability. However, they often suffer from the oscillatory false triggering, i.e. a series of self-sustaining repetitive false triggering induced after a fast switching. The purpose of this paper is to derive a design instruction to prevent this phenomenon. According to the previous study, the oscillatory false triggering was found to be caused by a parasitic oscillator circuit formed of a GaN-FET, its parasitic capacitance, and the parasitic inductance of the wiring. This paper analyzed the oscillatory condition to elucidate the design requirement to prevent the oscillatory false triggering. As a result, balancing the gate-drain parasitic capacitance and the common source inductance to achieve an appropriate ratio was found to be essential for preventing the oscillatory false triggering. Experiment successfully supported prevention of this phenomenon by balancing these two factors.

An Investigation into a Slight-Variation of the Transformer Effective Permeability in LLC Resonant Converter

Mostafa Noah, Shun Endo, Shota Kimura, Masayoshi Yamamoto, Jun Imaoka, Kazuhiro Umetani, Eiji Hiraki

2017 19TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'17 ECCE EUROPE) 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In the LLC resonant converter, the transformer core is usually gapped to realize the designed value of magnetizing inductance that allows for soft switching. The air gap length which is in a scale of millimeters may be affected by the humidity and long working hours of the ferrite material, resulting into a variation of the core permeability. Moreover, a slight variation of the transformer core permeability may be encountered with any possible change in the core temperature. In a proper transformer design, the transformer shall operate with an optimum value of effective permeability where the sum of both copper and core losses is minimal. In this paper, the transformer optimal design is presented. Moreover, the influence of the permeability on the transformer's copper and core losses is revealed. Furthermore, with the help of newly derived equations, the effect of the transformer's effective permeability on the LLC converter conduction turn-on and turn-off losses is reported. Along with the theoretical discussion, the analysis is supported with simulation and experimental results utilizing a 250W-200kHz prototype.

Compact Three-Phase AC Inductor Network for PFC Converter Using Magnetic Coupled Technique

Takuya Ozaki, Hiroki Nakaido, Kazuhiro Umetani, Eiji Hiraki, Tatsuya Ikenari, Shingo Kawano

IECON 2017 - 43RD ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 958 - 963 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Three-phase power factor correction (PFC) converters have been widely utilized in industrial power applications to improve the power factor and reduce current harmonics in three-phase power grid. The PFC converters commonly incorporate large-sized inductors as a noise filter to suppress the noise emission to the grid. However, as many other power converters, the PFC converters are intensely required to achieve high power density by reducing the size of the inductors. The purpose of this paper is to propose a magnetic structure to miniaturize the inductors. The proposed magnetic structure consists of an integrated magnetic component and a three-phase common-mode choke. By integrating the inductors, the proposed magnetic structure can miniaturize the magnetic core volume, while keeping the saturation current level and the noise filtering capability unchanged. Experiment was carried out to evaluate the appropriateness of the proposed magnetic structure as well as possible volume reduction. As a result, 32.2% volume reduction was found in the proposed magnetic structure without deterioration of the filtering capability.

Application of Extremum Co-Energy Principle for Homogenizing Current Distribution in Parallel-Connected Windings in Transformers: Design Optimization of Winding Turn Allocation among Winding Layers

Tomohide Shirakawa, Kazuhiro Umetani, Eiji Hiraki

2017 19TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'17 ECCE EUROPE) 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Parallel-connected windings are widely utilized for power transformers to reduce the copper loss. However, this reduction effect is often hindered by the proximity effect, which causes concentrated current distribution in parallel-connected windings. This paper addresses this issue by proposing a design optimization method of winding turn allocation among winding layers. This optimization method is based on the recently proposed insight on the proximity effect, referred to as the extremum co-energy principle. Experiment on a planar transformer with four primary winding layers was carried out to verify the proposed method. As a result, the proposed method successfully optimized the allocation of the winding turns to minimize the AC resistance.

Analytical Investigation on Design Instruction to Avoid Oscillatory False Triggering of Fast Switching SiC-MOSFETs

Yusuke Sugihara, Kimihiro Nanamori, Seiya Ishiwaki, Yuma Hayashi, Kyota Aikawa, Kazuhiro Umetani, Eiji Hiraki, Masayoshi Yamamoto

2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 5113 - 5118 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

SiC-MOSFETs have attracting increasing attention because of their outstanding characteristics that contributes to high efficiency and high power density of power converters. However, compared to conventional Si-IGBTs, SiC-MOSFETs are susceptible to false triggering, because they tend to generate large switching noise due to ultrafast switching capability and have a lower threshold voltage in high temperature operation. Particularly, disastrous oscillation of repetitive false triggering can occur after a fast turn-off, which is the severe issue for practical application of SiC-MOSFETs. The purpose of this paper is to give an instruction to avoid this phenomenon. This paper hypothesized that the repetitive false triggering is the parasitic oscillation caused by parasitic capacitance of SiC-MOSFET, and parasitic inductance of wiring. Based on this hypothesis, this paper analyzed the oscillatory condition of the parasitic oscillator to propose a design instruction to avoid the oscillatory false triggering. The result revealed that the parasitic inductance of the gate, drain, and source wiring should be designed so that the resonance frequency of the parasitic LC resonator in the gating circuit is far apart from that of the power circuit. This paper also presents experimental results that support appropriateness of the proposed design instruction.

Evaluation of Impact of Parasitic Magnetic Coupling in PCB Layout on Common Source Inductance of Surface Mounted Package

Ryunosuke Matsumoto, Kyota Aikawa, Akihiro Konishi, Kazuhiro Umetami, Eiji Hiraki

2017 IEEE 12TH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND DRIVE SYSTEMS (PEDS) 559 - 566 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Recently, the common source inductance (CSI) is regarded as one of the most important obstacles for achieving ultrafast switching of switching converters. The CSI is pointed out to be a major cause of deterioration of the switching speed and false triggering. Therefore, many design instructions of next generation switching devices, such as GaN-FETs and SiC-MOSFETs, have pointed out the necessity to reduce the CSI. Certainly, many of the next generation switching devices are provided in surface mount packages in order to enable PCB designers to minimize the CSI by eliminating the common source path. However, the parasitic magnetic coupling between the gating circuit and the power circuit may still add the CSI, although preceding studies have scarcely reported how greatly the PCB layout can affect the CSI and the switching waveforms. This paper experimentally evaluated the impact of the parasitic magnetic coupling of the PCB layout on the CSI of the surface mount package and on the switching waveforms. As a result, the parasitic magnetic coupling was found to cause the major difference in the CSI. In addition, large difference in the turn-off switching waveforms was found to be caused by the difference in the magnetic coupling. The reason is also analyzed and discussed in this paper, suggesting importance of appropriate design of the parasitic magnetic coupling in the PCB layout.

Measurement of the Common Source Inductance of Typical Switching Device Packages

Kyota Aikawa, Tomohumi Shiida, Ryunosuke Matsumoto, Kazuhiro Umetani, Eiji Hiraki

2017 IEEE 3RD INTERNATIONAL FUTURE ENERGY ELECTRONICS CONFERENCE AND ECCE ASIA (IFEEC 2017-ECCE ASIA) 1172 - 1177 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The common source inductance is one of the major causes of deterioration of the switching speed and susceptibility of the false triggering for semiconductor switching devices. Practical design of this inductance requires selection of an appropriate semiconductor package because this inductance is greatly dependent on the physical package structure. However, few studies have reported a list of the common source inductance of commercially available packages. In order to list and compare the common source inductance among typical semiconductor packages, this paper carried out measurement of this inductance of actual switching devices mounted on experimental PCBs. This paper employed a recently proposed straightforward measurement technique directly applicable to switching devices mounted on PCBs. As a result, a basic database of the common source inductance of typical packages was presented. The common source inductance was found to be determined mainly by the package type. However, in TO-247 and TO-220 packages, approximately one-third of the total common source inductance was found to possibly vary among the switching devices of the same package due to the dependence on the current rating. Investigation of the physical package structure implied that this dependence was caused by the stray inductance of the bonding wires connecting the semiconductor chip to the source terminal.

Elucidation of Quasi-Duality between Series-Series and Series-Parallel Topologies of Resonant Inductive Coupling Wireless Power Transfer Systems

Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

2017 IEEE 12TH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND DRIVE SYSTEMS (PEDS) 674 - 679 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Series-Series (SS) and Series-Parallel (SP) topologies are widely utilized in practical resonant inductive coupling wireless power transfer (RIC-WPT) systems owing to their simple circuit configurations. Conventionally, design optimization of the circuit parameters of these topologies were investigated separately, because these topologies are expressed by different equivalent circuits. However, analysis of these equivalent circuits is generally complicated due to the multiple resonant modes contained in the operation, which may cause difficulty in comparing the performance between the SS and SP topologies after design optimization of these topologies. This difficulty may prevent elucidating the methodology to select an appropriate topology that offers better output power or efficiency after design optimization. The purpose of this paper is to suggest a selection methodology of the SS and SP topologies by elucidating a novel insight that these topologies have the quasi-duality relation, in which the SP topology works approximately as the dual of the SS topology. This insight enables to share the analysis results between the topologies. As a result, both of these topologies were found to be expressed by a same novel equivalent circuit. Furthermore, the only difference between the SS and SP topologies were found to be the equivalent load resistance of this equivalent circuit, thus reducing the topology selection into selection of preferable load resistance. The appropriateness of the quasi-duality relation and the resultant equivalent circuit was successfully confirmed by the simulation and the experiment.

Soft-switching Technique Applicable to Capacitive Load for Resonant Inverter of Plasma Generator

Koji Itakura, Hiroaki Kakemizu, Hiroki Nakaido, Kazuhiro Umetani, Eiji Hiraki, Tatsuya Ikenari, Shingo Kawano

IECON 2017 - 43RD ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 1556 - 1562 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Recently, resonant inverters have been employed to generate high voltage high frequency AC power for plasma generator of the semiconductor processing equipment. This inverter is beneficial in low switching loss owing to its natural soft switching capability under inductive load impedance. Generally, the resonant inverter for plasma generator is designed to have inductive load using an impedance matching circuit that interfaces the inverter and the plasma reactor. However, the load impedance often fluctuates according to the state of the plasma, momentarily causing the capacitive load impedance. In this case, the inverter is generally controlled to restrict the output power for circuit protection from excessive switching loss, although this will result in unstable plasma, deteriorating the quality of the semiconductor processing. This paper addressed this difficulty by applying a soft switching technique to the resonant inverter. This soft-switching technique can be utilized regardless to the capacitive or inductive load. Experiment was carried out to evaluate the effectiveness of the proposed technique. As a result, the effective reduction of the switching loss was successfully verified even under the capacitive load impedance.

Simple Self-Driven Synchronous Rectifier for Resonant Inductive Coupling Wireless Power Transfer

Takahiro Koyama, Toru Honjo, Masataka Ishihara, Kazuhiro Umetani, Eiji Hiraki

2017 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC) 363 - 368 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Resonant inductive coupling wireless power transfer (RIC-WPT) is attracting attention as a convenient power supply method to small mobile apparatus. The efficiency and the power transfer capability of RIC-WPT has been known to be profoundly dependent on the quality factor of the receiving resonator. However, the quality factor of the receiving resonator tends to be deteriorated because of the conduction loss at the diode rectifier, particularly for low output voltage applications. In order to improve the efficiency and the power transfer capability, this paper propose a novel simple synchronous rectifier, which can reduce the conduction loss. The proposed rectifier has simple circuit configuration, which contributes to straightforward application to the wireless power transfer to small mobile apparatus with limited installation space. Experiment was carried out to verify the operation principle of the proposed rectifier. As a result, the proposed rectifier revealed successful suppression of the conduction loss. In addition, the experimental wireless power transfer system verified successful improvement in the rectification efficiency, supporting usefulness of the proposed rectifier for practical applications of the RIC-WPT for small mobile apparatus.

Simple Analytical Derivation of Magnetic Flux Profile Eliminating Source Current Ripple and Torque Ripple of Switched Reluctance Motors for Electric Vehicle Propulsion

Takayuki Kusumi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

2017 THIRTY SECOND ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC) 3142 - 3149 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a simple control technique for switched reluctance motors to eliminate both the source current ripple and the torque ripple simultaneously. The proposed control is a current tracking control based on a pre-computed magnetic flux profile. This profile is derived using a simple analytical SRM model without the magnetic saturation. Conventionally, the magnetic saturation is commonly utilized for limiting excessive magnetic flux induction to improve the torque output. However, in the proposed control, the magnetic flux profile is utilized for limiting the magnetic flux by control. By controlling without the magnetic saturation, elimination of the source current ripple and the torque ripple can be achieved regardless to the output power. Along with theoretical derivation of the magnetic flux profile, an experiment is carried out to evaluate the proposed control. The results revealed suppression of the source current ripple and the torque ripple simultaneously in comparison with the conventional square-wave current control.

Quasi-duality between SS and SP topologies of basic electric-field coupling wireless power transfer system

M. Ishihara, K. Umetani, H. Umegami, E. Hiraki, M. Yamamoto

Electronics Letters 52 ( 25 ) 2057 - 2059 2016年12月

掲載種別：研究論文（学術雑誌）

Series-series (SS) topology and series-parallel (SP) topology of the electric-field coupling wireless power transfer system are widely utilised for practical applications. However, selecting the appropriate circuit topology, which maximise the output power by design optimisation, is often difficult, because these circuit topologies are generally analysed using different circuit models. This difficulty by analysing novel equivalent circuits for SS and SP topologies is addressed. As a result, the output power of SP topology is found to be approximated by that in SS topology with transformed load impedance. This result can offer a simple strategy for topology selection as well as design optimisation.

DOI： 10.1049/el.2016.1253

A design guideline of parasitic inductance for preventing oscillatory false triggering of fast switching GaN-FET

Kazuhiro Umetani, Keisuke Yagyu, Eiji Hiraki

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 11 S84 - S90 2016年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

Gallium nitride field-effect transistors (GaN-FETs) are attractive devices because of its low on-state resistance and fast switching capability. However, they can suffer from false triggering caused by fast switching. Particularly, a disastrous oscillation of repetitive false triggering can occur after a turn-off, which may deteriorate the reliability of power converters. To address this issue, we give a design guideline to prevent this phenomenon. We analyze a simple circuit model to derive the condition of occurrence of this phenomenon, which is then verified experimentally. Results show that the parasitic inductance of the gating circuit, L-g, and that of the decoupling circuit, L-d, should be designed so that the LC resonance frequency of L-g and the gate-source capacitance of the GaN-FET does not coincide with that of L-d and the drain-source capacitance, respectively. (c) 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.22339

A Simple Behavior Model for Switched Reluctance Motors Based on Magnetic Energy

Takuto Hara, Takayuki Kusumi, Kazuhiro Umetani, Eiji Hiraki

2016 IEEE 8TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (IPEMC-ECCE ASIA) 109 - 115 2016年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A number of analytical models for switched reluctance motors have been proposed to promote development of control techniques that can alleviate the torque and source current ripples. However, these models can suffer from a large database of the nonlinearity as well as complicated derivation process of the torque and the voltage-current relation. The purpose of this paper is to propose a simple practical behavior model with small database and straightforward derivation of the torque and the voltage-current relation. The proposed model has a simple database of the magnetic energy as a matrix. The flux linkage and the electrical angle are chosen as the state variables. Along with theoretical formulation of the model, this paper presents a practical method of the model construction. In addition, experiments successfully predicted both torque and current waveforms, supporting appropriateness of the proposed model.

Lagrangian Derivation and Analysis of a Simple Equivalent Circuit Model of Wireless Power Transfer System with Dual Transmitting Resonators

Takahiro Koyama, Toru Honjo, Kazuhiro Umetani, Eiji Hiraki

2016 18TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'16 ECCE EUROPE) 2016年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a novel analysis method for the dual transmitting resonators wireless power transfer (DTR-WPT) system. The DTR-WPT is attractive for its higher efficiency and greater power transfer capability compared with the conventional single transmitting resonator wireless power transfer (STR-WPT) system. However, analytical understanding of the DTR-WPT is difficult due to its complicated operating principle caused by two transmitting resonators and a receiving resonator, which are all magnetically coupled each other. Therefore, practical applications of the DTR-WPT may be hindered by difficulty in establishing a design optimization method and a control scheme.This difficulty is addressed in this paper by proposing a novel simple equivalent circuit model of the DTR-WPT. Lagrangian dynamics is employed to derive this model. Brief analysis of this model showed improvement in the efficiency and the power transfer capability by the DTR-WPT compared with the conventional STR-WPT. In addition, the power transfer of the DTR-WPT system was found to be expressed by the same equivalent circuit model as the STR-WPT system. Therefore, similar design optimization methods and similar control schemes as for the STR-WPT are applicable to the DTR-WPT. Along with the theory, this paper presents experiments that verified appropriateness of the proposed model as well as the analysis results based on this model.

Simple Control Technique to Eliminate Source Current Ripple and Torque Ripple of Switched Reluctance Motors for Electric Vehicle Propulsion

Takayuki Kusumi, Takuto Hara, Kazuhiro Umetani, Eiji Hiraki

PROCEEDINGS OF THE IECON 2016 - 42ND ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 1876 - 1881 2016年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Switched reluctance motors (SRMs) are expected to be applied to propulsion systems of electric vehicles for their robust mechanical construction and cost-effectiveness. On the other hand, their large source current ripple and large torque ripple are main obstacles in practical applications of SRMs to vehicle propulsion. Certainly, a number of studies have been dedicated to address the torque ripple. However, unlike other motors driven by sinusoidal phase current waveforms, the large source current ripple of SRMs generally remains, even if the torque ripple is removed. The purpose of this paper is to propose a simple control technique of SRMs for vehicular propulsion by eliminating the source current ripple as well as the torque ripple. The proposed control is a current tracking control based on a pre-computed current profile. Because vehicular propulsion requires to instantaneously output large torque in sudden acceleration, SRMs tend to be designed to be propelled below the magnetic saturation in normal vehicle travel. Therefore, this proposed current profile is derived using a simple SRM analytical model without the magnetic saturation. In addition, the proposed current profile is determined so that the peak magnetic flux is minimized to offer high-speed current response at a high rotating velocity. Along with theoretical derivation of the proposed control, this paper also presents an experiment to verify the principle of the proposed control technique, which successfully revealed reduction of both the source current ripple and the torque ripple.

Copper Loss Analysis Based on Extremum Co-Energy Priciple for High Frequency Forward Transformers with Parallel-Connected Windings

Tomohide Shirakawa, Genki Yamasaki, Kazuhiro Umetani, Eiji Hiraki

PROCEEDINGS OF THE IECON 2016 - 42ND ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 1099 - 1105 2016年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The Dowell model is widely utilized for copper loss analysis of forward transformers. However, this model is not directly applicable to transformers with parallel-connected windings. The reason is that the Dowell model requires determining the AC current of all the windings in advance of analysis, although the AC current distribution in parallel connected windings is severely affected by disposition of the windings. This issue is addressed in this paper by employing the Dowell model in combination with a novel insight that the AC current is distributed in parallel-connected windings to give an extremum of the magnetic co-energy of the transformer. Simulation and experiment were carried out; and, the results supported appropriateness of the proposed copper loss analysis method.

Simple flux-based Lagrangian formulation to model nonlinearity of concentrated-winding switched reluctance motors 査読

K. Umetani, M. Yamamoto, E. Hiraki

Electronics Letters 51 ( 24 ) 1984 - 1986 2015年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ENGINEERING TECHNOLOGY-IET

© 2015 The Institution of Engineering and Technology. Practical applications of switched reluctance motors (SRMs) require control techniques that can solve large torque ripple and large current ripple in power supply. To promote development of these techniques, a simple Lagrangian formulation for flux-based nonlinear SRM models is proposed. This formulation can be analysed in combination with Lagrangian circuit models of motor drivers. The properness of the formulation is supported by an example of the analysis of the operation of a simple SRM driving system.

DOI： 10.1049/el.2015.0950

Lagrangian-based Equivalent Circuit of Basic Electric-Field Coupling Wireless Power Transfer System

Hirokatsu Umegami, Kazuhiro Umetani, Masayoshi Yamamoto, Eiji Hiraki

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 10 S168 - S170 2015年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

Electric-field coupling wireless power transfer has been commonly analyzed using the circuit model. However, the circuit behavior of this model is not necessarily apparent because their resonant modes can be far complicated than the basic LC oscillation. This issue is addressed in this paper by proposing a novel equivalent circuit for a basic wireless power transfer system. This equivalent circuit has a simpler topology than the conventional circuit model. Furthermore, the equivalent circuit allows intuitive understanding of three types of the resonant modes. Along with theoretical derivation of the proposed equivalent circuit, this paper also presents simulation results, which verified the appropriateness of the equivalent circuit. (C) 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.22180

Novel Simple Reactive Power Control Strategy With DC Capacitor Voltage Control for Active Load Balancer in Three-Phase Four-Wire Distribution Systems

Tint Soe Win, Yoshihiro Hisada, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 51 ( 5 ) 4091 - 4099 2015年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

This paper proposes a novel simple reactive power control strategy for the active load balancer (ALB) in three-phase four-wire distribution systems. The proposed reactive power control strategy may be applicable for adjustment of the source-side power factor under the balanced load condition. Only dc capacitor voltage control is used in the proposed control strategy. Therefore, the calculation blocks of the active and reactive components of the load currents are not necessary. The authors, thus, offer the simplest control strategy to control reactive power under the balanced load condition on three-phase four-wire distribution feeders. The basic principle of dc-capacitor-voltage-control-based reactive power control strategy is discussed in detail and then confirmed by digital computer simulation. A prototype experimental system was constructed and tested. Experimental results demonstrate that balanced source currents with reactive power control are achieved on three-phase four-wire distribution feeders. These experimental results also demonstrate that controlling the reactive power reduces the required power rating of the ALB compared with that of the conventional unity power factor control strategy.

DOI： 10.1109/TIA.2015.2437972

Experimental Validation of Normally-On GaN HEMT and Its Gate Drive Circuit

Takaharu Ishibashi, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka, Tamotsu Hashizume, Daigo Kikuta, Tetsu Kachi

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 51 ( 3 ) 2415 - 2422 2015年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Wide-bandgap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) are promising materials for next-generation power devices. We have fabricated a normally on GaN-based high-electron-mobility transistor (GaN HEMT) for power electronic converters. In this paper, the current collapse phenomena, which are distinctive characteristics of GaN devices, are evaluated in detail for several voltages with two switching frequencies. We also evaluate a gate drive circuit that we previously proposed for the normally on GaN HEMT with a single positive voltage source. We construct and test prototype circuits for a boost-type dc-dc converter and a single-phase full-bridge inverter with a gate drive circuit. The problems to be solved for the normally on GaN HEMT, which has a (static) voltage rating of over 600 V, are clarified on the basis of the experimental results.

DOI： 10.1109/TIA.2014.2369818

Reduced-Capacity Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders With Reactive Power Control

Hidenori Tanaka, Toshihiko Tanaka, Takaaki Wakimoto, Eiji Hiraki, Masayuki Okamoto

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 51 ( 1 ) 315 - 324 2015年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In this paper, we propose a new control algorithm to reduce the capacity of a previously proposed smart charger for electric vehicles (EVs) on single-phase three-wire distribution feeders with reactive power control. The basic principle of the proposed control algorithm is discussed in detail. It is shown that controlling the reactive power on the source side reduces the capacity of the previously proposed smart charger. A digital computer simulation is implemented to confirm the validity of the proposed control algorithm using PSIM software. A prototype experimental model is also constructed and tested. Experimental results demonstrate that balanced source currents with a power factor of 0.9, which is acceptable for Japanese home appliances, are obtained on the secondary side of the pole-mounted distribution transformer during both the battery charging and discharging operations in EVs. The capacity of dc capacitor C-DC is also reduced by 37% with the proposed reactive power control algorithm.

DOI： 10.1109/TIA.2014.2327156

Non-isolated Interleaved High Step-up Converter with Reduced Voltage Multiplier Stages and a Regenerative Turn-off Snubber

Kazuhiro Umetani, Eiji Hiraki, Masayoshi Yamamoto

2015 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 125 - 132 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a novel non-isolated high step-up converter suitable for miniaturization by high frequency design. High step-up converters with voltage multipliers are promising for high frequency design because many of them can be free from coupled inductors or transformers, which may lower the voltage gain due to the leakage inductance or may cause significant AC conduction loss in the primary winding. However, two issues can still hinder further miniaturization. One is that many multiplier stages may be needed to achieve extremely high voltage gain. The other is that high switching frequency may be restricted by severe turn-off voltage surge caused by high speed switching. The proposed converter addresses the former by applying a recently reported technique to a non-isolated boost converter. Additionally, the converter addresses the latter by proposing a simple passive regenerative turn-off snubber implementable only by two diodes and a capacitor. Experiments verified that the proposed converter achieves high voltage gain with fewer voltage multiplier stages compared to prior non-isolated high step-up converters. Additionally, the snubber successfully reduced the turn-off surge into half approximately without apparent deterioration of the efficiency.

Lagrangian-Based Derivation of a Novel Sliding-Mode Control for Synchronous Buck Converters

Kazuhiro Umetani, Masayoshi Yamamoto, Eiji Hiraki

IEEJ JOURNAL OF INDUSTRY APPLICATIONS 4 ( 6 ) 728 - 729 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ELECTRICAL ENGINEERS JAPAN

Sliding-mode control for power converters is gaining significant research interest for achieving a fast transient response to a step load change in a wide operating range. However, power converters also require better dynamic load regulation against load current fluctuations slower than the step change. This paper addresses this issue by deriving a novel control method for synchronous buck converters using Lagrangian dynamics. Simulation results verified improvement in dynamic load regulation against slow sinusoidal load current fluctuations.

DOI： 10.1541/ieejjia.4.728

Passive Regenerative Turn-off Snubber Composed of Two Diodes and a Capacitor for Two-Phase Interleaved Boost Chopper

Kazuhiro Umetani, Eiji Hiraki, Masayoshi Yamamoto

2015 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC) 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Communication relay stations often suffer from common-mode noise generated by high speed switching in a boost chopper equipped for power supply. This problem can be addressed by applying soft-switching techniques to the boost chopper, although this can lead to significant increase in the circuit volume. To address this difficulty, this paper proposes a novel passive regenerative turn-off snubber applicable to the two-phase interleaved boost chopper. The proposed snubber can add small circuit volume because it is implementable only by two diodes and a capacitor. Experiments are carried out to verify the operating principles of the proposed snubber. The results successfully verified suppression of the rising speed of the drain voltage at the turn-off in both of the phases without apparent deterioration of the efficiency.

Reactive Power Control Strategy Based on DC Capacitor Voltage Control for Active Load Balancer in Three-Phase Four-Wire Distribution Systems

Tint Soe Win, Toshihiko Tanaka, Masayuki Okamoto, Yoshihiro Hisada, Eiji Hiraki, Seong Ryong Lee

IEEJ JOURNAL OF INDUSTRY APPLICATIONS 4 ( 3 ) 158 - 165 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ELECTRICAL ENGINEERS JAPAN

This paper proposes a reactive power control strategy for the active load balancer (ALB) in three-phase four-wire distribution systems. The proposed reactive power control strategy is based on constant DC capacitor voltage control only, which is always used in active power line conditioners. Therefore, the proposed approach does not require active and reactive calculation blocks of load currents for the reference source current calculation. The power factor of the source side currents can be adjusted under the balanced load condition using the proposed reactive power control strategy. The basic principle of the reactive power control strategy for the ALB is discussed in detail and verified via digital computer simulation using power electronic simulation (PSIM) software. A prototype experimental model is constructed and tested to demonstrate the validity and high practicability of the proposed control strategy. Simulation and experimental results indicate that balanced source currents with a predefined power factor are achieved when the proposed control strategy is applied to the three-phase four-wire distribution systems.

DOI： 10.1541/ieejjia.4.158

High-frequency Induction Heating for Tiny Foreign Metals

Shinya Kurachi, Naoki Yamamoto, Hiroaki Yamada, Toshihiko Tanaka, Eiji Hiraki, Yukiharu Yamada, Tatsuya Nagao, Yasuhiro Miyake, Yujiro Noda

2015 9TH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND ECCE ASIA (ICPE-ECCE ASIA) 2203 - 2208 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The anxiety of tiny metal contamination into resin materials in the manufacturing process has become one of the serious issues. Because it may often cause of overheat in lithium-ion batteries, flat panel displays, and so on. Therefore, a study on detecting method of the tiny metals is a significant issue. The authors have been investigating the high-frequency induction heating (IH) based approach for tiny metals detection. In this paper, effective magnetic circuit design and IH conditions are discussed and demonstrated from theoretical and experimental point of view.

Peak Power Shaving of an Electric Injection Molding Machine With Supercapacitors

Hirofumi Akiyoshi, Eiji Hiraki, Toshihiko Tanaka, Masayuki Okamoto, Tadayoshi Matsuo, Kiyoshi Ochi

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 50 ( 2 ) 1114 - 1120 2014年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In this paper, we propose the control method of a peak shaving system for an electric injection molding machine (EIMM). The peak power shaver consists of a multiphase bidirectional dc-dc converter and supercapacitors (SCs), and is connected to a dc link of the inverter fed injection motor drive system of the EIMM. In the proposed control method, electric power is stored in the SCs through the multiphase bidirectional dc-dc converter with a pulsewidth-modulation rectifier while the injection motor is at rest. When the injection motor is accelerating, the stored power in the SCs together with the power from the distribution feeders is supplied to the injection motor. Thus, the peak power can be shaved. The basic principle of the proposed control method is discussed in detail, then confirmed by digital computer simulation and experimental setup. The simulation and experimental results demonstrate that the peak power is shaved by 70% using the peak power shaving system.

DOI： 10.1109/TIA.2013.2272433

MHz-class High-frequency Soft-switching GaN-based Inverter for Wireless Power Transmission via Electromagnetic Resonance

Keisuke Yoshizawa, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto

2014 INTERNATIONAL ELECTRONICS AND APPLICATION CONFERENCE AND EXPOSITION (PEAC) 451 - 455 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Wireless power transmission via magnetic resonance has been attracted and interested as long range wireless power transmission method. As a consequence, high-frequency inverter operating under high power conversion efficiency is required. In this paper, power conversion efficiency and power transmission efficiency of full bridge inverter using GaN devices are evaluated and discussed from the experimental point of view.

立体駐車場非接触給電システム用高周波リンクAC-ACコンバータ

河野真吾, 平木英治, 田中俊彦, 岡本昌幸

電気学会論文誌. D, 産業応用部門誌 134 ( 2 ) 139 - 146 2014年

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new concept for a contactless power supply system (CPS) in a mechanical multi-level parking tower for plug-in hybrid vehicles (PHVs) and electric vehicles (EVs). In recent years, PHVs and EVs have been commercialized as low environmental impact vehicles, and the demand for such vehicles is spreading rapidly. To cater to this increasing demand of PHVs and EVs, battery charging systems in the parking tower are necessary. Most multi-level parking towers have movable parking pallets that are electrically isolated from the building side. Because of the poor positional accuracy of the movable pallets, a contactless power transmission system between the utility grid in the building and the movable pallet is necessary. As for the CPS in the parking tower, a power conversion stage from commercial AC to high-frequency AC is necessary for size reduction. In general, such a power conversion system consists of power factor correction (PFC) converters and high-frequency inverters. Therefore, two or more conversion stages are necessary, which increases the power losses and cost. In this paper, a simple circuit configuration of a high-frequency link AC-AC converter for a CPS in a parking tower is proposed. The proposed high-frequency link AC-AC converter can directly convert commercial AC to high-frequency AC (HFAC) and HFAC to commercial AC again. Experiments are performed to demonstrate the validity of the proposed CPS. The proposed CPS is found to have a coupling coefficient of 0.75 for a contact-less transformer with a 10mm gap, and an efficiency of 86% can be achieved.

DOI： 10.1541/ieejias.134.139

マルチ出力可能なIHクッキングヒータ用高周波インバータ

廣川貴之, 平木英治, 田中俊彦, 今井慎, 安井健治, 住吉眞一郎

電気学会論文誌. D, 産業応用部門誌 134 ( 4 ) 477 - 478 2014年

記述言語：日本語出版者・発行元：一般社団法人電気学会

In this paper, a multiple-output high-frequency soft switching inverter is presented for home and business-use of IH cooking appliances. The proposed inverter is composed of parallel-connected single-switched multiresonant inverter cells. A detailed analysis indicates that the proposed inverter can control multiple-output power independently through a phase-shifted PWM scheme. The experimental results suggest that the prototype may be applied to multiple-output induction heating appliances.

DOI： 10.1541/ieejias.134.477

負荷側電力演算が不要な電気自動車用スマートチャージャの無効電力調整法

田中秀典, 田中俊彦, 岡本昌幸, 平木英治

パワーエレクトロニクス学会誌 40 63 - 69 2014年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

This paper proposes a novel reactive power control algorithm without load-side active power calculation for the previously proposed smart charger of Electric Vehicles (EVs) on single-phase three-wire distribution feeders. The basic principle of the proposed reactive power control algorithm is discussed in detail and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with a power factor of 0.9, which is acceptable value in Japanese regulation, are obtained on the secondary side of the pole-mounted distribution transformer during the battery charging operation.

DOI： 10.5416/jipe.40.63

Novel, Simple Reactive Power Control Strategy with DC Capacitor Voltage Control for Active Load Balancer in Three-Phase Four-Wire Distribution Systems

Tint Soe Win, Yoshihiro Hisada, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee

2014 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 3916 - 3921 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a novel, simple reactive power control strategy for the active load balancer (ALB) in three-phase four-wire distribution systems. The proposed reactive power control strategy is applicable for adjustment of the source-side power factor under the balanced load condition. Only DC capacitor voltage control is used in the proposed control strategy. Therefore, the calculation blocks of the active and reactive components of the load currents are not necessary. The authors, thus, offer the simplest control strategy to control reactive power under the balanced load condition on three-phase four-wire distribution feeders. The basic principle of DC capacitor voltage control based reactive power control strategy is discussed in detail, and then confirmed by digital computer simulation. A prototype experimental system was constructed and tested. Experimental results demonstrate that balanced source currents with reactive power control are achieved on three-phase four-wire distribution feeders. These experimental results also demonstrate that controlling the reactive power reduces the required power rating of the ALB compared to that of the existing control strategy, which achieves balanced source currents with unity power factor.

Reactive Power Control Strategy Based on DC Capacitor Voltage Control for Active Load Balancer in Three-Phase Four-Wire Distribution Systems

Tint Soe Win, Yoshihiro Hisada, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee

2014 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-HIROSHIMA 2014 - ECCE-ASIA) 3292 - 3297 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a reactive power control strategy for the active load balancer (ALB) in three-phase four-wire distribution systems. The proposed reactive power control strategy is based on constant DC capacitor voltage control, which is always used in active power line conditioners. Therefore, the proposed reactive power control strategy does not require active, reactive calculation blocks of load currents for the reference source current calculation. Balanced source currents with a predefined power factor can be achieved without unbalanced active and reactive components detection of the load currents. The basic principle of the reactive power control strategy for the ALB is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested to validate the feasibility of the proposed control algorithm. Simulation and experimental results demonstrate that balanced source currents with a predefined power factor are achieved in three-phase four-wire distribution systems.

Novel control algorithm for active load balancer in three-phase four-wire distribution systems 査読

Tint Soe Win, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee, Toshihiko Tanaka

IEEJ Journal of Industry Applications 3 ( 3 ) 286 - 287 2014年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electrical Engineers of Japan

Three-phase four-wire distribution systems are widely used in many countries. These distribution systems are used for both three-phase three-wire loads and single-phase two-wire consumer appliances, e.g., in South Korea and Myanmar. Because of the time-dependent load characteristics, unbalanced load conditions frequently occur, resulting in the unbalanced voltages for the three-phase and single-phase loads. In addition, these unbalanced load conditions cause more loss in the distribution transformer. This paper proposes a novel reference current generation method for active load balancer (ALB) in the three-phase four-wire distribution systems. The main advantages of the proposed method is that it uses only a constant DC capacitor voltage control for reference current generation without calculating the active and reactive currents in the three-phase four-wire distribution systems. The basic principle of the novel reference generation method in ALB is discussed and then confirmed on the basis of results of digital computer simulation using PSIM software.

DOI： 10.1541/ieejjia.3.286

Reducing capacity of smart charger for electric vehicles on single-phase three-wire distribution feeders with reactive power control 査読

Hidenori Tanaka, Takaaki Wakimoto, Toshihiko Tanaka, Masayuki Okamoto, Eiji Hiraki

IEEJ Journal of Industry Applications 3 ( 6 ) 437 - 445 2014年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electrical Engineers of Japan

This paper proposes a new control algorithm to reduce the capacity of the previously proposed smart charger for electric vehicles (EVs) on single-phase three-wire distribution feeders using reactive power control on the source side. The basic principle of the proposed reactive power control algorithm is discussed in detail. It is shown that controlling the reactive power on the source side reduces the capacity of the previously proposed smart charger. A digital computer simulation is carried out to confirm the validity of the proposed control algorithm using PSIM software. A prototype experimental model is constructed and tested. The experimental results demonstrate that balanced source currents with a power factor of 0.9, which conforms to Japanese regulations, are obtained on the secondary side of the pole-mounted distribution transformer during both the battery charging and discharging operations in EVs reducing the capacity of the smart charger by 31% in comparison to that of the smart charger with the previously proposed control algorithm.

DOI： 10.1541/ieejjia.3.437

A Novel Active Power Quality Compensator Topology with DC Voltage Balancer for Electrified Railways

Tint Soe Win, Eiji Hiraki, Toshihiko Tanaka

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 8 ( 6 ) 634 - 639 2013年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

This paper proposes a novel active power quality compensator (APQC) topology with a DC voltage balancer for electrified railways. The APQC is composed of a three-leg structure with two common DC capacitors. Two legs perform as two half-bridge inverters, which compensate the unbalanced active, reactive, and harmonic currents on the source side in the traction substation. The third leg controls two common DC capacitor voltages with a small amount of the output currents. Therefore, the current rating of the third leg can be reduced as compared to that of the already proposed three-leg structured APQC. In the control algorithm of the two half-bridge inverters, a strategy based on constant DC capacitor voltage control is used, which does not need any calculation blocks of the unbalanced active, reactive, and harmonic components of the load current to perform the APQC operation. Thus we offer the simplest algorithm for the proposed APQC. The basic principle of the proposed APQC topology with the DC voltage balancer is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that the proposed APQC can achieve balanced and sinusoidal source currents on the primary side of the Scott transformer in traction substations for electrified railways. (c) 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.21907

Smart Charger for Electric Vehicles With Power-Quality Compensator on Single-Phase Three-Wire Distribution Feeders

Toshihiko Tanaka, Tsukasa Sekiya, Hidenori Tanaka, Masayuki Okamoto, Eiji Hiraki

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 49 ( 6 ) 2628 - 2635 2013年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In this paper, we propose a smart charger for electric vehicles with a power-quality compensator. The proposed smart charger consists of four-leg insulated-gate bipolar transistors (IGBTs). Three legs are used for a single-phase full-bridge-based pulsewidth-modulated (PWM) rectifier, which converts power from ac to dc during the battery-charging operation or from dc to ac during the battery-discharging operation. This PWM rectifier can compensate reactive and unbalanced active currents on single-phase three-wire distribution systems because the third leg is connected to the neutral line of single-phase three-wire distribution feeders. The fourth leg is used as a bidirectional dc-dc converter for battery-charging and battery-discharging operations. The three-leg PWM rectifier uses only constant dc-capacitor voltage control, which is commonly used in active power line conditioners. Thus, the authors have developed the simplest possible control method for a single-phase power-quality compensator. The basic principle of the proposed smart charger is discussed in detail and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents are obtained on the secondary side of the pole-mounted distribution transformer for battery-charging and battery-discharging operations.

DOI： 10.1109/TIA.2013.2262915

オールメタル対応IH調理器を目的とした時分割制御高周波インバータ

廣川貴之, 平木英治, 田中俊彦, 岡本昌幸, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 133 ( 7 ) 692 - 699 2013年7月

記述言語：日本語出版者・発行元：一般社団法人電気学会

In recent years, induction heating (IH) cookers using a high-frequency (HF) inverter for home use have become increasingly popular because of their cleanliness, high efficiency, safety, and so on. With regard to the domestic consumer markets, effective applicability to a variety of pan materials such as low resistivity materials (aluminum and copper) and high-resistivity materials (iron and magnetic stainless steel) is one of the important issues. In this paper, a time-sharing HF inverter for IH cooking appliances that enables doubling of the output frequency of the switching operation is proposed. The proposed HF resonant inverter is able to reduce switching losses by the frequency doubler and the soft-switching operation. Furthermore, the current rating of the switching power devices is reduced because of the parallel-connected circuit configuration. The basic principle of the proposed time-sharing HF inverter is discussed in detail. The performance and effectiveness of the proposed time-sharing HF inverter are confirmed by experimental point of view.

DOI： 10.1541/ieejias.133.692

Reduced-Capacity Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders with Reactive Power Control

Hidenori Tanaka, Toshihiko Tanaka, Takaaki Wakimoto, Eiji Hiraki, Masayuki Okamoto

2013 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 5158 - 5164 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose a new control algorithm to reduce the capacity of a previously proposed smart charger for electric vehicles (EVs) on single-phase three-wire distribution feeders with reactive power control. The basic principle of the proposed control algorithm is discussed in detail. It is shown that controlling the reactive power on the source side reduces the capacity of the previously proposed smart charger. A digital computer simulation is implemented to confirm the validity of the proposed control algorithm using PSIM software. A prototype experimental model is also constructed and tested. Experimental results demonstrate that balanced source currents with a power factor of 0.9, which is acceptable for Japanese home appliances, are obtained on the secondary side of the pole-mounted distribution transformer during both the battery charging and discharging operations in EVs. This reduces the capacity of the smart charger by 32% compared with that of the smart charger with the previously proposed control algorithm.

Ubiquitous Power for Sectional Compact Emergency Shelter

Toshihiko Tanaka, Keiichi Kato, Shinichi Noriyasu, Eiji Hiraki, Makoto Koganei, Fusanori Miura, Masayuki Okamoto

2013 IEEE ECCE ASIA DOWNUNDER (ECCE ASIA) 404 - 408 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a mobile power for the Sectional Compact Emergency Shelter (SCES), which is used for the field hospitals, disaster response offices, and so on under the great disaster. The proposed mobile power consists of the fuel cells (FCs), photovoltaic cells (PVs) and lead-acid batteries. All of the power resources and necessary electrical equipments are constructed in a container car. Therefore, the constructed mobile power is easily moveable and constructive with the SCESs. The FCs can supply power continuously. The PVs are installed on the roof of SCES. The generated power from the PVs is fluctuated by weather conditions. Thus, the lead-acid batteries are installed for levering the difference between the generated power and consumed power in the SCES. The basic principle of the proposed ubiquitous power is discussed in detail, then confirmed by digital computer simulation using PLECS software. The simulation results demonstrate that the ubiquitous power can supply the power to the SCES continuously in winter in Japan. It is concluded that the proposed ubiquitous power is the good solution for power supply of SCES under the great disaster with the SCES.

Constant DC Capacitor Voltage Control Based Strategy for Active Load Balancer in Three-phase Four-wire Distribution System

Tint Soe Win, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee, Toshihiko Tanaka

2013 INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES AND SYSTEMS (ICEMS) 1560 - 1565 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Three-phase four-wire distribution systems are widely used in many countries. These power distribution systems are used for both three-phase three-wire loads and single-phase two-wire consumer appliances in South Korea, Myanmar and other countries. Unbalanced load conditions always occur in three-phase four-wire distribution systems. These unbalanced load conditions cause unbalanced voltages for three-phase and single-phase loads, and increase the loss in the distribution transformer. In this paper, we propose an active load balancer (ALB) based on constant DC capacitor voltage control for three-phase four-wire distribution systems. Constant DC capacitor voltage control is always used in active power line conditioners. The proposed control algorithm does not require any computation blocks to calculate the active and reactive currents on the distribution system. Balanced source currents with a unity power factor are obtained without any calculation blocks of the unbalanced active and reactive components on the load sides. The basic principle of the constant DC capacitor voltage control based strategy for the ALB is discussed in detail and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is also constructed and tested to validate the feasibility of the proposed control algorithm. Simulation and experimental results demonstrate that the proposed ALB can balance the source currents with a unity power factor for a three-phase four-wire distribution system.

A Study on GaN Inverter Based MHz Frequency Induction Heating for Tiny Metals

Naoki Yamamoto, Eiji Hiraki, Toshihiko Tanaka, Yukiharu Yamada, Tatsuya Nagao, Yasuhiro Miyake

39TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2013) 5023 - 5027 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The anxiety of merging tiny materials and resin materials in the manufacturing process has become one of the serious issues because it may become cause of overheat such as lithium-ion batteries, flat panel displays, and so on. Therefore, a study on detecting method of the tiny metals is a significant issue. A combination of high-frequency induction heating and thermal detection method is one of the useful approaches. In this paper, MHz-frequency GaN inverter based IH system is built and tested to verify heating size limitation of the tiny metals. Furthermore, the validity of the proposed method to detect the tiny metals by proposed IH thermal technique is evaluated and discussed in detail.

Dual-Frequency Multiple-Output Resonant Soft-Switching Inverter for Induction Heating Cooking Appliances

Takayuki Hirokawa, Eiji Hiraki, Toshihiko Tanaka, Makoto Imai, Kenji Yasui, Shinichiro Sumiyoshi

39TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2013) 5028 - 5033 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, a multiple-output high-frequency soft switching inverter is presented for home and business use "all metal" IH cooking appliances. The frequency and handling power of each output can be selected and regulated individually. The proposed inverter is composed of two single high-frequency circuit cells which are connected in parallel. Therefore, the number of switching devices in the proposed inverter can be significantly reduced. The simulation and experimental results indicate that the proposed circuit is suitable for the multiple output IH concepts such as free-zone induction heating, multi burner type cooking set-up and so on.

Resonant Gate Driver for Normally-On GaN High-Electron-Mobility Transistor

Takaharu Ishibashi, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka, Tamotsu Hashizume, Tetsu Kachi

2013 IEEE ECCE ASIA DOWNUNDER (ECCE ASIA) 365 - 371 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Wide bandgap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), are promised materials for next-generation power devices. The authors have recently fabricated a GaN-based high-electron-mobility transistor (HEMT), which is a normally-on device, for power electronics application. However, the power consumption in the constructed gate drive circuit increases when the GaN HEMT is used under higher-frequency operation. A new gate drive circuit with lower power consumption for the normally-on GaN HEMT is strongly required. In this paper, a new resonant gate drive circuit, which is most suitable for the newly fabricated GaN HEMT, is proposed. The validity and high practicability of the proposed resonant gate drive circuit are demonstrated by simulation and experimental results.

Experimental Validation of Newly Fabricated Normally-On GaN High-Electron-Mobility Transistor

Takaharu Ishibashi, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka, Tamotsu Hashizume, Daigo Kikuta, Tetsu Kachi

2013 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 1584 - 1591 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Wide bandgap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) are the promising materials for next-generation power devices. A normally-on GaN-based high-electron-mobility transistor (GaN HEMT) has been fabricated for power electronic converters. In this study, the current collapse phenomena, which are distinctive characteristics of GaN devices, are evaluated in detail under several voltages with two switching frequencies. Prototype circuits for a boost-type dc-dc converter and a single-phase full-bridge inverter, which use the newly fabricated GaN HEMT, are constructed and tested. The experimental results demonstrate that the newly fabricated normally-on GaN HEMT with the previously proposed gate drive circuit is suitable for use as a next-generation power device.

Sepic と Zeta コンバータの特性評価

中本貴之, 廣川貴之, 平木英治, 岡本昌幸, 田中俊彦

パワーエレクトロニクス学会誌 39 188 - 188 2013年

A New Current Control Strategy Based on the Internal Model Principle for a Current Balancer in Single-Phase Three-Wire Distribution Systems

Yusuke Baba, Yuji Wakasa, Eiji Hiraki, Toshihiko Tanaka, Masayuki Okamoto, Seong Ryong Lee

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 8 S95 - S101 2013年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

This paper proposes a new current control strategy that is based on the internal model principle for a current balancer in single-phase three-wire distribution systems. The proposed current control strategy includes a sinusoidal reference input model to achieve the zero steady-state error tracking. The appropriate control gains of this control strategy can be systematically determined by using a state-feedback controller design method via linear matrix inequalities. The basic principle of the proposed control strategy is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that zero steady-state error tracking is achieved by the proposed control strategy. Also, balanced source currents are obtained on the secondary side of a pole-mounted distribution transformer while the load conditions are unbalanced. (c) 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.21924

A Large-Capacity Capacitor Simulator with an Inner-Series Resistor

Okamoto Masayuki, Hiraki Eiji, Tanaka Toshihiko, Tanaka Atsushi

IEEJ Journal of Industry Applications 2 ( 4 ) 204 - 210 2013年

記述言語：英語出版者・発行元：The Institute of Electrical Engineers of Japan

This paper proposes a universal large-capacity capacitor simulator. The proposed simulator consists of a main chemical capacitor and three-leg IGBTs. One leg of the IGBTs acts as a bidirectional dc-dc converter. The other two legs are used for a single-phase PWM rectifier. In the capacitor-charging operation, the bidirectional dc-dc converter is used as a boost converter. Most of the power supplied by the load is supplied to the utility through the single-phase PWM rectifier. In the capacitor-discharging operation, the bidirectional dc-dc converter acts as a buck converter. Most of the power supplied to the load is from the utility through the single-phase PWM rectifier. A new control method, which can perform as an inner-series resistor in a supercapacitor (SC), is also proposed for an SC simulator. The basic principle of the proposed capacitor simulator is discussed in detail. The validity and high applicability of the proposed large-capacity capacitor simulator are confirmed using PSIM software. A prototype experimental model is constructed and tested. The experimental results demonstrate that the proposed capacitor simulator acts both as an ideal large-capacity capacitor and as an SC with an inner-series resistor.

DOI： 10.1541/ieejjia.2.204

その他リンク： https://jlc.jst.go.jp/DN/JALC/10020770012?from=CiNii

A starting method of the harmonic current compensator using a hybrid active filter for wind power generation systems with soft starters

Hiroaki Yamada, Eiji Hiraki, Toshihiko Tanaka

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 7 S139 - S145 2012年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

This paper proposes a starting method of the harmonic current compensator using a hybrid active filter for wind power generation systems. The active filter (AF) in the proposed method of the hybrid power filter behaves as a resistor and reactive power compensator to suppress the inrush current and leading currents for the passive filter (PF) under the starting condition. The basic principle of the proposed starting method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the proposed starting method can overcome the inrush and leading currents for the PF, building up the DC capacitor voltage of the AF. IEEJ Trans 2011 DOI: 10.1002/tee.21815

DOI： 10.1002/tee.21815

Topology for Current Balancer with Half-Bridge Inverters in Single-Phase Three-Wire Distribution Systems with DC-Capacitor-Voltage Balancer

Yusuke Baba, Kazuya Sugahara, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka

ELECTRICAL ENGINEERING IN JAPAN 180 ( 4 ) 38 - 46 2012年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

This paper proposes a new topology for a current balancer with half-bridge inverters in single-phase three-wire distribution systems. Two half-bridge inverters are connected to the sources. The midpoint of the two capacitors on the DC-side is connected to a neutral line. The two half-bridge inverters function as a current balancer for single-phase three-wire distribution systems by exchanging the active and reactive power on each feeder through the two DC capacitors. The third leg functions as a DC-capacitor-voltage balancer for two DC capacitors connected to the half-bridge inverters. Thus, balanced source voltages and currents are obtained on the secondary side on the pole-mounted distribution transformer with balanced DC-capacitor voltages. The basic principle of the proposed current balancer is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results show that balanced source voltages and currents are obtained on the secondary side on the pole-mounted distribution transformer with balanced DC-capacitor voltages. (C) 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(4): 38-46, 2012; Published online in Wiley Online Library (wileyonlinelibrary. com). DOI 10.1002/eej.22277

DOI： 10.1002/eej.22277

IHクッキングヒータ用時分割制御高周波インバータの小型化に関する検討

廣川貴之, 平木英治, 田中俊彦, 岡本昌幸

電気学会研究会資料. SPC, 半導体電力変換研究会 2012 ( 96 ) 81 - 85 2012年7月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

筆者らは先に2台の1石型高周波インバータを並列接続した回路構成のIHクッキングヒータ用時分割制御高周波インバータを提案し,実証評価を行ってきた.本稿では2台のインバータ内のインダクタを結合させることによる回路の小型化について検討したので報告する.

直流キャパシタ電圧一定制御を用いた単相三線式配電用電流バランサの制御法

馬場雄介, 岡本昌幸, 平木英治, 田中俊彦, LEE Seong Ryong

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 132 ( 5 ) 581 - 587 2012年5月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a strategy based on constant dc-capacitor voltage control for a current balancer in single-phase three-wire distribution systems. The proposed control strategy involves the use of only the constant dc-capacitor voltage control block commonly used in active power conditioners for the calculation of the compensation current. No calculation block is required to obtain the reactive and unbalanced-active components. Thus, we provide the simplest possible control strategy for the current balancer. The basic principle of the proposed control method is discussed in detail and its validity, which is confirmed by a digital computer simulation using PSIM software, is shown. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with a power factor of unity are obtained on the secondary side of a pole-mounted distribution transformer while unbalanced load current conditions with a lagging power factor are retained.

DOI： 10.1541/ieejias.132.581

A constant DC voltage control-based strategy for an active power quality compensator in electrified railways with improved response

Norio Ishikura, Keisuke Ishibashi, Eiji Hiraki, Toshihiko Tanaka

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 7 ( 3 ) 316 - 321 2012年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

This paper proposes a constant DC voltage control-based strategy for an active power quality compensator (APQC) used in electrified railways. The proposed strategy consists of only an I-PD-based constant DC capacitor voltage control with an added moving-average type low-pass filter (LPF). The added LPF improves the response of the constant DC capacitor voltage control for the APQC. Thus we offer the simplest control method for the APQC used in electrified railways with improved response. The basic principle of the proposed control strategy is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with unity power factor are obtained on the primary side of the Scott transformer in the traction substation systems, improving the response by one-fourth as compared to that of the previously proposed control method. (C) 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.21733

インダクタを結合した構造を有するIHクッキングヒータ用時分割制御高周波インバータの実証評価 (第195回定例研究会)

廣川貴之, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 38 141 - 148 2012年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

This paper represents the practical evaluations of an improved time-sharing high-frequency resonant soft-switching inverter for all metal induction heating (IH) cooking appliances. By introducing inductor coupling technology, the number of the circuit components and a physical volume of the circuit can be reduced. A design procedure of the coupling inductor is discussed in detail. Furthermore, two IH power regulation sequences; phase shifted PWM and PAM are compared to the viewpoint of the power conversion efficiency.

DOI： 10.5416/jipe.38.141

The Practical Evaluations of Time-Sharing High-Frequency Resonant Soft-Switching Inverter for All Metal IH Cooking Appliances

Takayuki Hirokawa, Eiji Hiraki, Toshihiko Tanaka, Masayuki Okamoto, Mutsuo Nakaoka

38TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2012) 3302 - 3307 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper represents the practical evaluations of time-sharing high-frequency resonant soft-switching inverter composed of two multi-resonant sub inverter cells in parallel for common series resonant load for all metal induction heating (IH) cooking appliances. Together with a fixed switching frequency resonant current, IH power regulation is carried out by phasor angle control scheme with phase-shifted PWM scheme. In particular, this high-frequency multi-resonant inverter can efficiently operate under the conditions of load resonant frequency changing mode; frequency doubler mode (100 kHz) for low resistivity metal IH loads and fundamental switching frequency mode (50 kHz) for high resistivity metal IH loads, respectively. The feasible performance of the time-sharing high-frequencys inverter are demonstrated and discussed in detail.

Performance Analysis for High-Frequency link AC-AC Contact-less Power Supply System in Parking Tower

Shingo Kawano, Eiji Hiraki, Toshihiko Tanaka, Masayuki Okamoto

38TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2012) 645 - 650 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In tandem with the penetration of PH V as well as EV, contact-less power supply system in parking towers have become important subjects. In parking towers, EV and PHV are charged on the traveling pallets, supply power is to be transmitted from the building to travelling pallets. In this paper, high-frequency link AC-AC converter for contact-less power supply system in parking tower is newly proposed and its basic operation and performance have been demonstrated from computer aided simulation and experiment.

Smart Charger for Electric Vehicles with Power Quality Compensator on Single-Phase Three-Wire Distribution Feeders

Toshihiko Tanaka, Tsukasa Sekiya, Hidenori Tanaka, Eiji Hiraki, Masayuki Okamoto

2012 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 3075 - 3081 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose a smart charger for electric vehicles (EVs) with a power quality compensator. The proposed smart charger consists of four-leg IGBTs. Three legs are used for a single-phase full-bridge-based PWM rectifier, which converts power from ac to de during the battery-charging operation, or from de to ac during the battery-discharging operation. This PWM rectifier can compensate reactive and unbalanced active currents on single-phase three-wire distribution systems because the third leg is connected to the neutral line of singlephase three-wire distribution feeders. The fourth leg is used as a bidirectional dc-de converter for battery-charging and discharging operations. The three-leg PWM rectifier uses only constant dc-capacitor voltage control, which is commonly used in active power line conditioners. Thus, the authors have developed the simplest possible control method for a single-phase power quality compensator. The basic principle of the proposed smart charger is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents are obtained on the secondary side of the pole-mounted distribution transformer for battery-charging and discharging operations.

Peak Power Shaving of an Electric Injection Molding Machine with Supercapacitors

Hirofumi Akiyoshi, Eiji Hiraki, Toshihiko Tanaka, Masayuki Okamoto, Tadayoshi Matsuo Eiji Hiraki, Kiyoshi Ochi

2012 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 2590 - 2595 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose the control method of a peak shaving system for an electric injection molding machine (EIMM). The peak power shaver consists of a multiphase bidirectional dc-dc converter and supercapacitors (SCs), and is connected to a dc link of the inverter fed injection motor drive system of the EIMM. In the proposed control method, electric power is stored in the SCs through the multiphase bidirectional dc-dc converter with a PWM rectifier while the injection motor is at rest. When the injection motor is accelerating, the stored power in the SCs together with the power from the distribution feeders is supplied to the injection motor. Thus, the peak power can be shaved. The basic principle of the proposed control method is discussed in detail, then confirmed by digital computer simulation and experimental setup. The simulation and experimental results demonstrate that the peak power is shaved by 70% using the peak power shaving system.

High Frequency-link AC-AC Wire-less Power Supply System in Parking Tower

Eiji Hiraki, Shingo Kawano, Toshihiko Tanaka, Masayuki Okamoto

2012 15TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (EPE/PEMC) 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In tandem with the penetration of PHV as well as EV, wire-less power supply system in parking towers have become important subjects. In parking towers, EV and PHV are charged on the traveling pallets, supply power is to be transmitted from the building to travelling pallets. In this paper, high frequency link AC-AC converter for non-contact power supply system in parking tower is newly proposed and its basic operation performance have been demonstrated from computer aided simulation and experiment.

直流電圧平衡化回路を有するハーフブリッジインバータを用いた単相三線式配電用電流バランサ

馬場雄介, 菅原和也, 岡本昌幸, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 131 ( 7 ) 880 - 887 2011年7月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new topology for a current balancer with half-bridge inverters in single-phase three-wire distribution systems with a three-leg inverter. Two half-bridge inverters are connected to the sources. The midpoint of two capacitors on the DC-side is connected to a neutral line. The two half-bridge inverters perform a current balancer for single-phase three-wire distribution systems by exchanging the active and reactive power on the each feeder through the two DC-capacitors. The third-leg performs a DC-capacitor-voltage balancer for the two DC-capacitors connected to the half-bridge inverters. Thus, balanced source voltages and currents are obtained on the secondary-side on the pole-mounted distribution transformer with balanced DC-capacitor voltages. The basic principle of the proposed current balancer is discussed in detail, and then, confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results show that balanced source voltages and currents are obtained on the secondary-side on the pole-mounted distribution transformer with balanced DC-capacitor voltages.

DOI： 10.1541/ieejias.131.880

A Large-Capacity Capacitor Simulator with an Inner-Series Resistor

Toshihiko Tanaka, Atsushi Tanaka, Masayuki Okamoto, Eiji Hiraki

IECON 2011: 37TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY 1052 - 1057 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a universal large-capacity capacitor simulator. The proposed simulator consists of a main electrolytic capacitor and three-leg IGBTs. One leg of the IGBTs acts as a bidirectional dc-dc converter. The other two legs are used for a single-phase PWM rectifier. In the capacitor-charging operation, the bidirectional dc-dc converter is used as a boost converter. Most of the power supplied by the load is injected to the utility through the single-phase PWM rectifier. In the capacitor discharging-operation, the bidirectional dc-dc converter acts as a buck converter. Most of the power supplied to the load is from the utility through the single-phase PWM rectifier. A new control method, which can perform an inner-series resistor in a supercapacitor (SC), is also proposed for an SC simulator. The basic principle of the proposed capacitor simulator is discussed in detail. The validity and high applicability of the proposed large-capacity capacitor simulator are confirmed using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that the proposed capacitor simulator acts both as an ideal large-capacity capacitor and as an SC with an inner-series resistor.

GaNデバイス用高速ドライブ回路の開発

石橋卓治, 岡本昌幸, 平木英治, 田中俊彦, 橋詰保, 橋詰保, 加地徹, 加地徹

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 62nd 2011年

A Novel Type Time-Sharing High-Frequency Resonant Soft-Switching Inverter for All Metal IH Cooking Appliances

Takayuki Hirokawa, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

IECON 2011: 37TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY 2526 - 2532 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, a novel type time-sharing high-frequency resonant soft-switching inverter composed of combining two-phase multi-resonant sub inverter cells in parallel for common series resonant tank load is demonstrated originally for all metal induction heating cooking appliances, together with a fixed output frequency resonant current phasor angle control scheme by phase-shifted PWM which is suitable for high frequency power regulation. In particular, this high-frequency multiresonant inverter with lossless snubbing capacitors for ZVS can efficiently operate under the conditions of load resonant frequency changing mode; frequency doubler mode(100kHz) and switching frequency mode(50kHz) for low resistivity metal IH and high resistivity metal IH loads, respectively. The feasible operating performances of experimental setup implementation are evaluated and discussed in detail. The practical effectiveness of this high frequency resonant inverter is confirmed for all metal IH cooking appliances on the basis of simulation and experimental results.

Loss Evaluation of an AC-AC Direct Converter with a New GaN HEMT SPICE Model

Masayuki Okamoto, Genki Toyoda, Eiji Hiraki, Toshihiko Tanaka, Tamotsu Hashizume, Tetsu Kachi

2011 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 1795 - 1800 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Wide-band-gap semiconductors, such as gallium nitride (GaN) and silicon carbide (SiC), are expected to be used as materials for new switching devices with low loss and high switching speed. The authors have recently developed a GaN-based high-electron-mobility-transistor (HEMT) for application to power electronics. In this paper we present models of a GaN-based transistor and Schottky barrier diode (SBD) for a simulation program with integrated circuit emphasis (SPICE). The results of the SPICE simulation show that the static and dynamic characteristics of GaN- based devices are precisely simulated by the SPICE models. The application of a GaN-based device to a single-phase AC-AC direct converter results in a reduction of power loss of over 30% compared with a silicon-based one.

直流電圧一定制御を用いた単相三線式配電用電流バランサの制御法

馬場雄介, 福井博一, 岡本昌幸, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 36 ( 36 ) 168 - 168 2011年

非接触給電用高周波電力変換回路のシミュレーション評価

河野真吾, 岡本昌幸, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 36 ( 36 ) 187 - 187 2011年

直列抵抗を模擬可能な大容量キャパシタシミュレータ

田中敦士, 岡本昌幸, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 36 ( 36 ) 190 - 190 2011年

A Half-Bridge Inverter Based Current Balancer with the Reduced DC Capacitors in Single-Phase Three-Wire Distribution Feeders

Yusuke Baba, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka

2011 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE) 4233 - 4239 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a half-bridge inverter based current balancer in single-phase three-wire distribution systems with the reduced dc capacitors. The proposed current balancer can use a 6-in-1 IGBT module. Two legs perform a half-bridge inverter based current balancer, which compensates the reactive and unbalanced active components on the source-side. The third-leg performs a power de-coupler with a dc-capacitor voltage balancer. This power de-coupler sinks the power fluctuation, which flows into the dc capacitors, caused by the unbalanced conditions of two half-bridge inverters. Thus the capacity of the dc capacitors of the half-bridge inverter based current balancer can be dramatically reduced as compared to those of the previously proposed current balancer. The basic principle of the proposed half-bridge inverter based current balancer with the reduced dc capacitors is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that the balanced source currents are obtained on the secondary-side of the pole-mounted distribution transformer, reducing the capacity of the dc capacitors of the half-bridge inverter based current balancer.

立体駐車場非接触給電システム用周波リンクAC-ACコンバータ

河野真吾, 岡本昌幸, 平木英治, 田中俊彦

信学技報, IEICE Technical Report 2011 ( 305(EE2011 24-30) ) 7 - 12 2011年

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

近年のEVやPHVの普及に伴い,立体駐車場での充電が必要となってきた.立体駐車場では,車両の乗ったパレットが移動を行うため,立体駐車場ビル本体からパレットを介して車両を充電することになる.本稿では,ビル本体に設置された電源系統からパレットヘ200V/60(50)Hzの商用交流を非接触で供給する高周波リンクAC-ACコンパータを提案し,実験とシミュレーションにより有用性を明らかにする.

学界情報国際会議レポート：The 36th Annual Conference of the IEEE Industrial Electronics Society (IECON2010) November 7 - 10, 2010, Glendale, USA

平木英治

電気学会論文誌. D, 産業応用部門誌 131 ( 3 ) NL3_4 2011年

ＩＨクッキングヒータ用チャージブースト型２出力フルブリッジインバータの実証評価

銭谷紳, 岡本昌幸, 平木英治, 田中俊彦, 定方秀樹, 藤田篤志, 中岡睦雄

パワーエレクトロニクス学会誌 36 ( 36 ) 103 - 109 2011年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

In this paper, a multi output high frequency soft switching inverter topology is presented for home use IH cooking appliances. The proposed inverter system is comprised of simple power circuitry and unique control scheme. The detailed analysis shows that the proposed inverter has low harmonic distortion, low switching losses and wide output powerrange. A detailed PWM procedure is illustrated as well. Through simulation and experimental results, the proposed IH system is verified.

DOI： 10.5416/jipe.36.103

電気自動車用スマートチャージャ

田中秀典, 関谷司, 岡本昌幸, 平木英治, 田中俊彦

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 62nd 2011年

マルチレベルインバータを用いた無効電力補償装置

伊藤北斗, 岡本昌幸, 平木英治, 田中俊彦

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 62nd 2011年

高周波ソフトスイッチングハーフブリッジインバータにおける寄生インダクタンスを考慮した動作解析

松井光生, 岡本昌幸, 平木英治, 田中俊彦

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 62nd 2011年

高い降圧比を有するインダクタ結合形DC-DCコンバータの損失分析

渡辺潤, 岡本昌幸, 平木英治, 田中俊彦

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 62nd 2011年

A half-bridge inverter based active power quality compensator with a DC voltage balancer for electrified railways

Tint Soe Win, Yusuke Baba, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka

Proceedings of the International Conference on Power Electronics and Drive Systems 185 - 190 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper proposes a half-bridge inverter based Active Power Quality Compensator (APQC) with a DC voltage balancer for electrified railways. The APQC is composed of three-leg structured power devices with two common DC capacitors. The first two legs perform as two half-bridge inverters to generate compensation currents and the third-leg is used for DC voltage balancer. The first-leg is connected to β-phase and the second-leg is connected to α-phase. Two DC capacitors are connected in series and midpoint is grounded. These two half-bridge inverters exchange and balance active power for two feeders through two common DC capacitors and compensate reactive and harmonic components of the distorted load currents. The third-leg controls two common DC capacitors to balance voltage level of each other. Using proposed APQC, the primary side of Scott transformer attains balanced and sinusoidal source currents. The principle and control algorithm of proposed a half-bridge inverter based APQC is discussed in detail. The proposed APQC is confirmed by both the PSIM computer simulation software and prototype experiment system. Simulation results show that the proposed APQC can achieve balanced and sinusoidal source currents in secondary side of Scott transformer. © 2011 IEEE.

DOI： 10.1109/PEDS.2011.6147244

Control strategies of active power line conditioners in single-phase circuits

Toshihiko Tanaka, Masayuki Okamoto, Eiji Hiraki

8th International Conference on Power Electronics - ECCE Asia: "Green World with Power Electronics", ICPE 2011-ECCE Asia 1813 - 1820 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper deals with two control strategies for the active power line conditioners in single-phase circuits. The first one is a constant dc capacitor voltage control based strategy, which is commonly used in the active power line conditioners. Any detection blocks of the fundamental active, reactive, and harmonic components are not necessary in this method. Thus we offer the simplest way to compensate the fundamental reactive and harmonic currents on the source-side. The other is a reactive power control based strategy, which is with the correlation and cross-correlation coefficients between the feeder voltage and load current. Controlling the detected fundamental reactive component with the cross-correlation coefficient on the source-side reduces the capacity of the PWM inverter, which performs the active power line conditioners. The basic principles of the proposed control strategies are discussed in detail, and then applied to the single-phase active power line conditioners in single-phase based distribution systems. These sigle-phase distributin systems are used in the single-phase three-wire systems and electrified railways. The validity and excellent practicability of the proposed control strategies are confirmed by experimental results. © 2011 IEEE.

DOI： 10.1109/ICPE.2011.5944516

An isolated bi-directional soft switching DC-DC converter for energy storage system and its voltage stress suppression approach

Kazumasa Hirao, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka

Proceedings of the International Conference on Power Electronics and Drive Systems 555 - 560 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In recent years, kinetic energy storage systems with electric double layered capacitor (EDLC) bank have been widely studied and developed for the fuel cell electric vehicles(FCEV). In this paper, a full-bridge/push-pull inverter based isolated bi-directional DC-DC soft switching converter for EDLC interface is proposed. The DC-DC converter mentioned here has the great advantage that the number of the switching power devices can be reduced compared to the conventional full-bridge/full-bridge inverter based DC-DC converter. The lower conduction losses can be achieved by this advantage as well as cost reduction. Though, a non-negligible drawback of the full-bridge/push-pull inverter based DC-DC converter has been revealed that is high voltage stress caused by the voltage ringing through the lossless snubber capacitor and leakage inductance of the high frequency transformer. To eliminate this drawback, a low leakage transformer is implemented to the DC-DC converter. The computer aided simulation and the experimental results demonstrate that the adequacy of the proposed circuit and its voltage suppression technique. © 2011 IEEE.

DOI： 10.1109/PEDS.2011.6147304

A ubiquitous power with DC micro-grid for sctional compact emergency shelters

Keiichi Kato, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka, Makoto Koganei, Fusanori Miura

Proceedings of the International Conference on Power Electronics and Drive Systems 436 - 440 2011年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper proposes a mobile power for the Sectional Compact Emergency Shelter (SCES), which is used under the great disaster. The proposed mobile power consists of the Fuel Cells (FCs), photovoltaic cells (PVs) and lithium-ion rechargeable batteries. This mobile power is constructed in a container car. Therefore, the constructed mobile power is easily moveable and constructible with the SCESs. The authors have named it a "ubiquitous power". The FCs in the ubiquitous power can supply electrical power and waste-heated water. The waste-heated water can be used to the SCESs for a floor heating in winter. The lithium-ion rechargeable batteries level the difference between generated power and consumed power in the SCESs. The number of the SCESs, which proposed one ubiquitous power can supply power continuously, is decided considering both the depth of discharge (DOD) of the batteries and the thermal energy of the waste-heated water from the FCs. It is shown that proposed one ubiquitous power can supply twenty SCESs in winter in Japan. © 2011 IEEE.

DOI： 10.1109/PEDS.2011.6147285

直列抵抗を模擬可能な大容量キャパシタシミュレータの制御法

田中敦士, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 130 ( 10 ) 1189 - 1190 2010年10月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new control method for the previously proposed large-capacity capacitor simulator, which can perform an inner series resistor of the EDLCs. In the proposed large-capacity capacitor simulator, one of three legs performs a bi-directional dc-dc converter. The others are used for a single-phase PWM rectifier. In the charging operation of the proposed large-capacity simulator, one-leg is used as a boost converter. Most power, which is stored in the proposed simulator, is injected to the utility through the PWM rectifier. In the discharging operation, the one-leg performs a buck converter. Most power, which is supplied to the load, is from the utility through the PWM rectifier. Thus the proposed simulator performs a large-capacity capacitor with an inner resistor in both charging and discharging operations. The basic principle of the proposed simulator is discussed in detail. The validity and excellent practicability of the proposed control method for the large-capacity capacitor simulator are confirmed using PSIM software.

DOI： 10.1541/ieejias.130.1189

絶縁型双方向DC-DCコンバータの動作解析 (電子通信エネルギー技術)

平生和雅, 岡本昌幸, 平木英治

電子情報通信学会技術研究報告 110 ( 151 ) 23 - 28 2010年7月

直流電圧一定制御を用いた単相三線式配電用電流バランサの制御法

福井博一, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 130 ( 7 ) 935 - 936 2010年7月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper deals with applying the constant dc voltage control based algorithm to the current balancer in single-phase three-wire secondary distribution systems. The power flows into a three-leg inverter, which performs the current balancer, are discussed, and then we show that only the reactive power flows into the three-leg inverter. This demonstrates that the required-capacity of the dc capacitor can be reduced as compared to that of the active power quality compensator used in the electrified railways. This reduced-capacity dc capacitor results in the rapid and stable balancing. The basic principle of the proposed method is discussed in detail, and then confirmed by digital computer simulation. Digital computer simulation results demonstrate that the balanced source currents with unity power factor are obtained remaining the unbalanced load currents conditions.

DOI： 10.1541/ieejias.130.935

高周波リンク非対称ZCS-PWM制御DC-DCコンバータの実証評価と検討

三島智和, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 130 ( 5 ) 605 - 613 2010年5月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a novel Zero Current Switching (ZCS)-PWM controlled half-bridge DC-DC converter with High-Frequency (HF)-link. The newly-proposed soft switching DC-DC converter consists of a multi-resonant half-bridge HF-isolated inverter controlled by an asymmetrical PWM scheme and a center-tapped diode rectifier with a choke input filter. In order to attain the wide range of soft-commutation under the condition of constant switching frequency, the single Active Edge-Resonant Cell (AERC) that is composed of a lossless inductor and a switched resonant capacitor is originally employed for the half-bridge inverter arm, providing and assisting ZCS operations in the switching power devices. The ZCS-PWMDC-DC converter treated here is evaluated in experiments using the 800 W-55 kHz prototype. The practical effectiveness of the proposed soft switching DC-DC converter is actually demonstrated and discussed with the experimental results under open loop and closed loop configurations. Finally, the feasibility of the DC-DC converter topology is discussed from the view points of the high efficiency and high power density.

DOI： 10.1541/ieejias.130.605

ソフトスタータ付き風力発電システム用ハイブリッドフィルタの始動法

山田洋明, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 130 ( 4 ) 574 - 575 2010年4月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new method of starting the hybrid power filter for wind power generation systems with soft starter. In the proposed method, an active filter of the hybrid power filter behaves a resistor for the source current under the starting condition. Thus the inrush phenomena of the passive filter are perfectly suppressed. The basic principle of the proposed starting method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the proposed starting method can overcome the inrush currents for the passive filter, building up the dc voltage of the active filter.

DOI： 10.1541/ieejias.130.574

家庭用IH調理器への応用を目的とした簡易型PFC機能を持つ2ステージソフトスイッチング高周波インバータ

河口祐樹, 平木英治, 田中俊彦, 定方秀樹, 藤田篤志, 大森英樹, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 130 ( 4 ) 450 - 458 2010年4月

記述言語：日本語出版者・発行元：一般社団法人電気学会

In recent years, consumer induction-heating (IH) cooking appliances have grown increasingly popular because of their easy cleaning, high efficiency, safety, and controllability. IH food cooking system for consumer home use are indispensable to heat various metallic pans, such as aluminum, copper, stainless steel, and iron cast for further diffusing. Furthermore, these appliances have to satisfy the utility AC grid harmonics regulations of IEC61000-3-2. To meet these requirements, this paper proposes a two-stage soft-switching high-frequency inverter with simple PFC function that is suitable for consumer IH cooking appliances. The proposed system comprises a soft-switching chopper based boost PFC converter with passive snubber and phase-shifted PWM controlled ZVZCS high-frequency inverter. In order to satisfy the utility AC grid current harmonic regulations, a simple PFC control technique with discontinuous current mode is introduced. This technique as well as the fundamental operating performances of the proposed IH system is tested. The effectiveness of proposed IH system is substantially proved from a practical point of view on the basis of the experimental results.

DOI： 10.1541/ieejias.130.450

A High Frequency-Link Bidirectional DC-DC Converter for Super Capacitor-Based Automotive Auxiliary Electric Power Systems

Tomokazu Mishima, Eiji Hiraki, Mutsuo Nakaoka

JOURNAL OF POWER ELECTRONICS 10 ( 1 ) 27 - 33 2010年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER HEIDELBERG

This paper presents a bidirectional DC-DC converter suitable for low-voltage super capacitor-based electric energy storage systems. The DC-DC converter presented here consists of a full-bridge circuit and a current-fed push-pull circuit with a high frequency (HF) transformer-link. In order to reduce the device-conduction losses due to the large current of the super capacitor as well as unnecessary ringing, synchronous rectification is employed in the super capacitor-charging mode. A wide range of voltage regulation between the battery and the super capacitor can be realized by employing a Phase-Shifting (PS) Pulse Width Modulation (PWM) scheme in the full-bridge circuit for the super capacitor charging mode as well as the overlapping PWM scheme of the gate signals to the active power devices in the push-pull circuit for the super capacitor discharging mode. Essential performance of the bidirectional DC-DC converter is demonstrated with simulation and experiment results, and the practical effectiveness of the DC-DC converter is discussed.

DOI： 10.6113/JPE.2010.10.1.027

ハイブリッドフィルタを用いたソフトスタータ付き風力発電システム用高調波電流補償装置の始動法

山田洋明, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 35 ( 35 ) 129 - 135 2010年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

This paper proposes a new starting method of the harmonic current compensator using the hybrid active filter for wind power generation systems. In the proposed method, an active filter of the hybrid power filter behaves a resistor and reactive power compensator to suppress the source currents oscillation and leading currents under the starting conditon. The basic principle of the proposed starting method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the proposed starting method can overcome the inrush and phase-leading currents, building up the dc capacitor voltage of the active filter.

DOI： 10.5416/jipe.35.129

A Comparative Evaluation of DCM Control and CCM Control for Soft-Switching PFC Converter

Yuki Kawaguchi, Eiji Hiraki, Toshihiko Tanaka, Hideki Sadakata, Atsushi Fujita, Hideki Omori, Mutsuo Nakaoka

IECON 2010: 36TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Harmonic currents generated from the power electric equipment such as IH cooking heaters involve harmful influences to the other equipments connected to the utility grid. As for the IH cooking appliances, adding the PFC converter to the input stage of IH cooking heater is one of the practical solutions to suppress harmonic current influences. In this paper, two operation modes; DCM and CCM for the PFC converter are compared and tested from the view points of magnetic volume and power quality to clarify the suitable operation mode for consumer IH cooking appliance.

Performance Verification of a Novel Soft Switching Three-Phase Utility Frequency AC to High Frequency AC Direct Power Converter with PFC Function for Industrial IH Applications

Takaaki Takahara, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka, Tamotsu Hashizume, Tetsu Kachi

PROCEEDINGS OF 14TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (EPE-PEMC 2010) 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents performance characteristics of a novel soft switching three-phase utility frequency AC (UFAC) to high frequency AC (HFAC) direct power converter with PFC function for industrial induction heating (IH) applications. The proposed "simple three-phase system" consists of a single-phase UFAC to HFAC direct converter unit in each phase, three-phase low pass filter and three-phase IH load. This power converter can regulate the output power under a condition of the constant frequency zero voltage soft switching (ZVS) commutation principle on the basis of unique asymmetrical PWM control scheme. In this paper, high frequency IH output and utility AC current characteristics of three-phase direct converter supposed 5kW class IH system are demonstrated and evaluated from computer aided simulation with PSIM software. Furthermore, basic performance analysis of the single-phase converter unit is evaluated from an experimental point of view.

電動式射出成形機用 Add-on 式エネルギー回収システムの省エネ効果

高橋圭介, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 130 ( 5 ) 713 - 714 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：一般社団法人電気学会

The regenerative energy from the motor drive systems used in the injection molding is consumed by resistors connected to the DC bus of the inverters. Recently the recovery systems of the regenerative energy with a bi-directional DC-DC converter and capacitors have been developed. In this paper a new control strategy of the EDLC based energy recovery system is proposed. The basic principle of the proposed control strategy and the power losses consumed in the energy recovery system are discussed in detail. The validity and practicability are confirmed by digital computer simulation.

DOI： 10.1541/ieejias.130.713

A New Half-Bridge Based Inverter with the Reduced-Capacity DC Capacitors for DC Micro-Grid

Toshihiko Tanaka, Tsukasa Sekiya, Yusuke Baba, Masayuki Okamoto, Eiji Hiraki

2010 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION 2564 - 2569 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new half-bridge based inverter for the DC micro-grid. The proposed topology consists of a three-leg inverter, which can be constructed by an intelligent power module (IPM). Using the IPM gives cost-effective inverters for the dc micro-grid. In the proposed half-bridge based topology with a three-leg inverter, two legs are used for two single-phase half-bridge inverters, where the neutral line is grounded. The third leg performs a power de-coupler balancing the mean value of two dc capacitor voltages. This power de-coupler exchanges the energies between two dc capacitors connected to two single-phase half-bridge inverters. Thus the capacity of the dc capacitors of the half-bridge inverters can be dramatically reduced as compared to those of the previously proposed half-bridge inverters for the dc micro-grid. The basic principle of the proposed half-bridge based inverter is discussed in detail, and then confirmed by digital computer simulation using PSIM software. Simulation results demonstrate that the capacity of the dc capacitors is reduced by one fortieth as compared to those of the previously proposed half-bridge based inverter used in the dc micro-grid.

DOI： 10.1109/ECCE.2010.5617983

A Charge Boost Type Multi Output Full Bride High Frequency Soft Switching Inverter for IH Cooking Appliance

Shin Zenitani, Masayuki Okamoto, Eiji Hiraki, Toshihiko Tanaka

PROCEEDINGS OF 14TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (EPE-PEMC 2010) 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, a multi output high frequency soft switching inverter topology is presented for home use IH cooking appliances. The proposed inverter system is comprised of simple power circuitry and unique control scheme. The detailed analysis shows that the proposed inverter has low harmonic distortion, low switching losses and wide output power range. A detailed PWM procedure is illustrated as well. Through simulation and experimental results, the proposed IH system is verified.

結合インダクタを有する降圧形DC-DCコンバータ

渡辺潤, 平木英治, 田中俊彦

2010年電子情報通信学会総合大会 2010 338 - 338 2010年

家庭用ＩＨクッキングヒータ用ソフトスイッチングＰＦＣコンバータにおけるＤＣＭ制御とＣＣＭ制御の実証的比較評価

河口祐樹, 平木英治, 田中俊彦, 定方秀樹, 大森英樹, 中岡睦雄

パワーエレクトロニクス学会誌 35 ( 35 ) 114 - 121 2010年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

Harmonic currents in the utility side generated from the power electric equipment such as IH cooking heaters involve harmful influences to the other electrical applications. To suppress harmonic influences, adding the PFC converter to the input stage of IH cooking heater is one of the practical solutions. In this paper, two operation modes; DCM and CCM for the PFC converter are compared and tested from the view points of magnetic volume of the boost and filter inductors, source current harmonics suppression, power conversion efficiency and input power factor to clarify the suitable operation mode for home-use IH cooking appliance.

DOI： 10.5416/jipe.35.114

A half-bridge inverter based active power quality compensator for electrified railways

T. Tanaka, K. Ishibashi, N. Ishikura, E. Hiraki

2010 International Power Electronics Conference - ECCE Asia -, IPEC 2010 1590 - 1595 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper proposes a new half-bridge inverter based active power quality compensator (APQC) for electrified railways with a three-leg inverter. The first-leg is connected to α-phase, and the second-leg is connected to β-phase. The midpoint of two capacitors on the dc side is connected to the ground line. These two half-bridge inverters exchange the active power on the each feeder each other through two dc capacitors, and compensate the negative-sequence and harmonic components of the load currents. The third-leg performs a dc voltage balancer for two dc capacitors connected to the half-bridge inverters. Thus the balanced and sinusoidal source voltages and currents factor are attained on the primary side of the Scott transformer with the balanced dc capacitor voltages. The basic principle of the proposed half-bridge inverter based APQC is discussed in detail, and then confirmed by digital computer simulation using PSIM software. Simulation results demonstrate that the balanced source currents with the unity power factor are obtained on the primary side the Scott transformer in the traction substation systems balancing two dc capacitor voltages. © 2010 IEEE.

DOI： 10.1109/IPEC.2010.5543371

A New Current Balancer in Single-Phase Three-Wire Secondary Distribution Feeders Using the Correlation Coefficients

Toshihiko Tanaka, Hirokazu Fukui, Eiji Hiraki, Shuuji Watanabe, Shinji Fukuma

ELECTRICAL ENGINEERING IN JAPAN 169 ( 1 ) 50 - 58 2009年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SCRIPTA TECHNICA-JOHN WILEY & SONS

This paper proposes a new current balancer in single-phase three-wire secondary distribution systems using the correlation coefficients. The components of the load currents correlative to the primary side voltage waveform, which correspond to the active currents, are detected in each feeder, then the nonactive and unbalanced-active components are compensated on the source side. The balanced currents with unity power factor are obtained in each feeder. The basic principle of the proposed method is discussed in detail, and then confirmed by digital computer simulation. A prototype experimental system is constructed and tested. Experimental results demonstrate that the balanced source currents with unity power factor are obtained in spite of unbalanced load currents. (C) 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(1): 50-58, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20843

DOI： 10.1002/eej.20843

変換器容量の低減を目的とした電気鉄道用パワーラインコンディショナの制御法

石倉規雄, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 129 ( 9 ) 907 - 913 2009年9月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new control method for reducing the capacity of an active power quality compensator with a three-leg inverter used in electrified railways. In the proposed control method, the fundamental reactive and unbalanced-active components of the load currents are detected. The non-active and unbalanced-active components are compensated on the source side with the fundamental reactive power control. This reactive power control reduces the capacity of the three-leg inverter, which performs the active power quality compensator. The basic principle of the proposed control method is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A reduced-scale experimental model is constructed and tested. Experimental results demonstrate that the balanced sinusoidal source currents with the power factor of 0.9 are obtained, reducing the capacity of the three-leg inverter by 13% as compared to the already proposed control method.

DOI： 10.1541/ieejias.129.907

双方向チョッパとPWM整流器を用いた大容量キャパシタシミュレータ

西村和則, 松本脩平, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 129 ( 8 ) 852 - 853 2009年8月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a large-capacity capacitor simulator consisting of a chemical capacitor and three-leg converter. One of three legs performs a bi-directional chopper. The others are used for a PWM rectifier. In the charging mode the most of the power stored in the chemical capacitor is injected to the utility through the PWM rectifier. In the discharging mode the power is supplied to the chemical capacitor side from the utility through the PWM rectifier. Thus the proposed simulator performs a large-capacity capacitor. The basic principle of the proposed simulator is discussed in detail. A prototype experimental model is constructed and tested. Experimental results demonstrate the validity and excellent practicability of the proposed simulator.

DOI： 10.1541/ieejias.129.852

A Constant DC Voltage Control Based Compensation Method of an Active Power Quality Compensator for Electrified Railways

Toshihiko Tanaka, Norio Ishikura, Eiji Hiraki

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 4 ( 3 ) 435 - 441 2009年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

This paper proposes a novel and simple control method for the active power quality compensators (APQCs) used in electrified railways. The proposed method uses only the constant dc capacitor voltage control block, which is commonly used in the APQCs. No detection blocks of the harmonic, reactive, and negative-sequence components are necessary. Thus we offer the simplest way to compensate the harmonic, reactive, and negative-sequence currents on the primary side of the Scott transformer in the traction substation. The basic principle of the proposed control method is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that the balanced source currents with the unity power factor are obtained on the primary side with the proposed control method, which uses only the constant dc capacitor voltage control. (C) 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

DOI： 10.1002/tee.20428

A Push-Pull Converter Based Bidirectional DC-DC Interface for Energy Storage Systems

Eiji Hiraki, Kazumasa Hirao, Toshihiko Tanaka, Tomokazu Mishima

EPE: 2009 13TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS, VOLS 1-9 5842 - 5851 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In recent years, power electronic energy storage systems using Super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge/centertapped push-pull circuit with active clamp-based soft switching bidirectional DC-DC converter and its control method are presented and discussed. From the results of basic experimental demonstration, the proposed system is able to perform adequate charging and discharging operation between low-voltage high-current super capacitor side and high-voltage low-current side with drive train and main battery. In addition, RCDi snubber losses appeared in the basic circuit topology are drastically reduced by ZCS/ZVS operation with the assistance of newly added active clump circuit, as well as ZVS operation with lossless snubber capacitor in high-voltage primary side.

A Comparison of Operation Mode for Soft-Switching PFC Converter for Induction Heating Cooking Appliance

Yuki Kawaguchi, Eiji Hiraki, Toshihiko Tanaka, Hideki Sadakata, Atsushi Fujita, Hideki Omori, Mutsuo Nakaoka

IECON: 2009 35TH ANNUAL CONFERENCE OF IEEE INDUSTRIAL ELECTRONICS, VOLS 1-6 13 - 18 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Harmonic currents generated from the power electric equipment such as IH cooking heaters involve harmful influences to the other equipments connected to the utility grid. As for the 111 cooking appliances, adding the PFC converter to the input stage of IH cooking heater is one of the practical solutions to suppress harmonic current influences. In this paper, two operation modes; DCM and CCM for the PFC converter are compared and tested from the view points of magnetic volume and power quality to clarify the suitable operation mode for consumer IH cooking appliance.

DOI： 10.1109/IECON.2009.5414802

A Novel Soft Switching Three-Phase Utility Frequency AC to High Frequency AC Direct Power Converter with PFC Function for Industrial IH Appliance

Takaaki Takahara, Yuki Kawaguchi, Eiji Hiraki, Toshihiko Tanaka, Kazunori Nishimura

2009 INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND DRIVE SYSTEMS, VOLS 1 AND 2 1192 - + 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents performance characteristics of a novel soft switching three phase utility frequency AC (UFAC) to high frequency AC (HFAC) direct converter with PFC function for industrial induction heating and melting applications The proposed "simple three phase system" consists of single phase UFAC to HFAC direct converter in each phase, three phase low pass filter and IH load. This power converter can regulate the output power under a condition of a constant frequency zero voltage soft switching (ZVS) commutation principle on the basis of unique asymmetrical PWM control scheme. In this paper, the input and output characteristics of proposed direct power converter on the basis of computer aided simulation are illustrated and discussed. Furthermore, Y-connected 3 phi working coils for IH load with the balanced coupling coefficient in each phase is designed and evaluated from an experimental point of view.

A Constant DC Voltage Control Based Strategy for an Active Power Quality Compensator Used in Electrified Railways with Improved Response

N. Ishikura, E. Hiraki, T. Tanaka

IECON: 2009 35TH ANNUAL CONFERENCE OF IEEE INDUSTRIAL ELECTRONICS, VOLS 1-6 3023 - 3028 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a constant dc voltage control based strategy for an active power quality compensator (APQC) used in electrified railways. The proposed strategy consists of only an I-PD based constant de capacitor voltage control with an added moving average type low-pass filter (LPF). The added LPF improves the response time of the constant dc capacitor voltage control for the APQC. Thus we offer the simplest control method for the APQC used in electrified railways with the improved response time. The basic principle of the proposed control strategy is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A proto-type experimental model is constructed and tested. Experimental results demonstrate that the balanced source currents with the unity power factor are obtained on the primary side the Scott transformer in the traction substation systems, improving the response time by one-fourth as compared to that of the previously proposed control method.

DOI： 10.1109/IECON.2009.5415311

Stand-alone photovoltaic generation system with combined storage system using EDLC

Hiroaki Nakayama, Eiji Hiraki, Toshihiko Tanaka, Noriaki Koda, Nobuo Takahashi, Shuji Noda

IECON Proceedings (Industrial Electronics Conference) 883 - 888 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper is mainly concerned with a newly proposed stand-alone photovoltaic (PV) generation system. This system permanently drives the load with the capacity of about several W, such as the security camera devices, street light and outdoor measurement system, by the electric power by the solar cell. Its fundamentals of operating performances are illustrated and evaluated on the experimental results. Its effectiveness is proved on the basis of the experimental results from a practical point of view. Because of its possibility to drive without the electric power from the commercial power line, this system is especially effective in the out-door use where the commercial electric power line is not supported. ©2009 IEEE.

DOI： 10.1109/IECON.2009.5415035

A Large-Capacity Capacitor Simulator with a PWM Rectifier and Bi-directional DC-to-DC Converter

A. Tanaka, E. Hiraki, T. Tanaka

2009 INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND DRIVE SYSTEMS, VOLS 1 AND 2 1318 - 1323 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a universal large-capacity capacitor simulator consisting of a chemical capacitor and three-leg converter. One of three legs performs a bi-directional dc-to-dc converter. The others are used for a single-phase PWM rectifier. In the charging operation of the proposed large-capacity simulator, one-leg is used as a boost converter. Most power, which is stored in the proposed simulator, is injected to the utility through the PWM rectifier. In the discharging operation, the one-leg performs a buck converter. Most power, which is supplied to the load, is from the utility through the PWM rectifier. Thus the proposed simulator performs a large-capacity capacitor in both charging and discharging operations. The basic principle of the proposed simulator is discussed in detail. For an EDLC simulator operation, series resistors should be considered. A new control method, which performs the series resistor, is also proposed. The validity and excellent practicability of the proposed large-capacity capacitor simulator are confirmed using the PSIM software.

DOI： 10.1109/PEDS.2009.5385902

Basic study of a phase-shifted soft switching high-frequency inverter with boost PFC converter for induction heating

Yuki Kawaguchi, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

JOURNAL OF POWER ELECTRONICS 8 ( 2 ) 192 - 199 2008年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER HEIDELBERG

This paper is mainly concerned with a high frequency soft-switching PWM inverter suitable for consumer induction heating systems. The proposed system is composed of a soft switching chopper based boost PFC converter stage with passive snubber and phase shifted PWM controlled full bridge ZVZCS high frequency inverter stage. Its fundamental operating performances are illustrated and evaluated in the experimental results. Its effectiveness is substantially proved on the basis of the experimental results from a practical point of view.

直流電圧一定制御を用いた電気鉄道用パワーラインコンディショナの制御法

田中俊彦, 石倉規雄, 福井博一, 平木英治

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 128 ( 2 ) 145 - 146 2008年2月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a novel control method for the active power quality compensator used in electrified railways. In the proposed method, only the constant dc voltage control is used to compensate the non-active and unbalanced active currents on the secondary side of the Scott transformer. Any schemes to detect the reactive and harmonic currents are not needed. Thus we can provide the simplest way to improve the power quality in electrified railways. The basic principle of the proposed control method is discussed. The validity and excellent practicability are confirmed by digital computer simulation using PSIM soft ware.

DOI： 10.1541/ieejias.128.145

電源電圧と負荷電流の相関と相互相関に着目した単相三線式配電用電流バランサの制御法

福井博一, 平木英治, 田中俊彦, 福間慎治

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 128 ( 1 ) 34 - 40 2008年1月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new control method of the current balancer for single-phase three-wire secondary distribution systems using the correlation and cross-correlation coefficients. The components of the load currents correlative and cross-correlative to the primary side voltage waveform, which correspond to the active and reactive currents, are detected in each feeder, then the reactive and unbalanced-active components are compensated on the source side. The balanced currents with the variable power factor are obtained in each feeder. The basic principle of the proposed method is discussed in detail, and then confirmed by digital computer simulation. A proto-type experimental system is constructed and tested. Experimental results demonstrate that the balanced source currents with the power factor of 0.9 are obtained in spite of unbalanced load currents.

DOI： 10.1541/ieejias.128.34

Stand-alone Photovoltaic Generation System with Combined Storage using lead Battery and EDLC

Hiroaki Nakayama, Eiji Hiraki, Toshihiko Tanaka, Noriaki Koda, Nobuo Takahashi, Shuji Node

2008 13TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE, VOLS 1-5 1877 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This research is mainly concerned with a stand-alone photovoltaic (PV) generation system for low power DC applications placed where the commercial AC grid connection is not supported. In this paper, basic and improved circuit topologies and the control schemes of stand-alone photovoltaic generation system are proposed. To prevent battery from deep discharge, Electric Double Layer Capacitor (EDLC) is incorporated into the proposed systems as combined energy storage device in parallel with conventional lead battery. The fundamentals of operating performances and effectiveness of proposed stand-alone PV system are illustrated and evaluated on the basis of a practical point of view.

A Novel Type Single-Stage ZVS-PWM High-Frequency Load Resonant Inverter with High Performance PFC Rectifier for Consumer IH Appliances

Hisayuki Sugimura, Sang-Pil Mun, Soon-Kurl Kwon, Shinichiro Sumiyoshi, Hideki Omori, Eiji Hiraki, Mutsuo Nakaoka

ICEMS 2008: PROCEEDINGS OF THE 11TH INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES AND SYSTEMS, VOLS 1- 8 1215 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：WORLD PUBLISHING CORPORATION

This paper presents a high-efficiency-high power density one stage ZVS-PWM single-ended push-pull (SEPP) high frequency Inverter with new PFC functional scheme. This high-frequency resonant series load resonant inverter with lossless snubbing capacitors is composed of a passive PFC converter operating at one diode conducting bridge circuit and asymmetrical ZVS-PWM high frequency resonant direct inverter without the bulky electrolytic capacitor stage for boosted DC voltage smoothing. In addition, this one stage utility frequency AC (UFAC) to high frequency AC (HFAC) conversion circuit has only one diode conducting mode in the diode bridge rectifier with boost inductor. The operating principle of the one stage UFAC to HFAC series load resonant inverter with lossless capacitors is described by using the switching mode equivalent circuits in addition to the simulated operating voltage and current waveforms. The operating performances of this high-frequency ZVS-PWM resonant direct inverter with lossless snubbing capacitors are illustrated on the basis of simulation analysis which includes its UFAC-to-HFAC power regulation characteristics, soft switching operating range, UFAC side power factor characteristics and UFAC side line current harmonics characteristics by FFT analysis. In principle, the effectiveness of this UFAC-to-HFAC direct power frequency converter using IGBTs for consumer high-frequency IH appliances is evaluated and proved on the basis of simulation results.

Active Voltage Clamped Edge-Resonant Soft Switching PWM High Frequency Cyclo-Converter Using Bidirectional Switches

Hisayuki Sugimura, Sang-Pil Mun, Soon-Kurl Kwon, Eiji Hiraki, Mutsuo Nakaoka

2008 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-10 3917 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents a utility frequency AC (UFAC) to high frequency AC (HFAC) direct power frequency conversion pulse modulated conditioning circuit using bidirectional power switches. This power converter can efficiently operate under a principle of active zero voltage clamped soft commutation for consumer induction heating (IH) fixing roller for copy machine and printer. This HFAC direct power frequency converter defined as resonant high frequency PWM controlled power frequency converter using bidirectional switches is developed and evaluated in this paper for consumer IH fixing heat roller using industrial HFAC power supply. Its operating principle is described on the basis of switching mode equivalent circuits during switching one cycle period. It is evaluated on the basis of its simulation and experimental results on the performances of HFAC direct power frequency converter treated here including various duty factor control variable vs. HFAC power regulation characteristics as well as zero voltage soft switching ranges.

New Built-in Induction Heating Cooker Using High-Frequency ZVS-PWM Converter with Single Stage Circuit Topology

Hisayuki Sugimura, Bishwajit Saha, Shinichiro Sumiyoshi, Hideki Omori, Sang-Pil Mun, Soon-Kurl Kwon, Eiji Hiraki, Mutsuo Nakaoka

2008 IEEE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETING, VOLS 1-5 1010 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents a novel soft-switching PWM utility frequency AC to high frequency (HF) AC power conversion circuit incorporating boost-active clamp single stage inverter topology. This power converter is more suitable and acceptable for cost effective HF consumer induction heating (IH) applications. Its operating principle and the operation modes are presented using the switching mode equivalent circuits in addition to the operating voltage and current waveforms. The operating performances of this high frequency inverter using the latest IGBTs are illustrated, which includes HFAC power regulation ranges and actual efficiency characteristics based on zero voltage soft switching (ZVS) operation ranges and the power dissipation analysis as compared with those of the previously developed high frequency inverter. In addition, a dual mode selected control scheme of this high frequency inverter based on a constant frequency asymmetrical pulse width modulation (PWM) and pulse density modulation (PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. This power frequency converter practical effectiveness is substantially proved on the basis of experimental results from practical design example.

A New Soft-Switching PWM High Frequency Half-Bridge Inverter Linked DC-DC Converter with Diode-Clamped Active Edge Resonant Snubbers

Hisayuki Sugimura, Tetsuya Etoh, Toshimitsu Doi, Keiki Morimoto, Bishwajit Saha, Sang Pil Mun, Eiji Hiraki, Mutsuo Nakaoka

2008 IEEE INDUSTRY APPLICATIONS SOCIETY ANNUAL MEETING, VOLS 1-5 2410 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, the novel circuit topology of half-bridge soft switching PWM DC-DC power converter with a high frequency planar transformer link was presented. The operating principle and switching pattern of the half-bridge soft switching PWM DC-DC power converter described for 40 kHz, 36V and 400A output were illustrated and discussed for low voltage and large current output applications such as telecommunication and automotive applications. The power loss analysis of the proposed soft switching DC-DC power converter was discussed and evaluated as compared with hard switching PWM DC-DC power converter with a high frequency link. The practical effectiveness of the proposed DC-DC power converter operation under soft switching PWM scheme was actually proved from a practical point of view and the high efficiency and power density of this converter could be achieved on the basis of experimental results for low voltage and large current power supplies.

Feasible Evaluation of a Full-Bridge Inverter for Induction Heating Cooking Appliances with Discontinuous Current Mode PFC Control

Yuki Kawaguchi, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka, Atsushi Fujita, Hideki Omori

2008 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-10 2948 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A high frequency soft-switching PWM inverter with PFC function suitable for consumer IH cooking appliance is presented in this paper. The proposed system is composed of a soft switching chopper based boost PFC converter with passive snubber and phase shifted PWM controlled full bridge ZVZCS high frequency inverter. In order to meet the utility AC grid current harmonic regulation, a simple PFC control technique with discontinuous current mode is introduced and tested in addition to the fundamental operating performances of the proposed system. Effectiveness of proposed IH system is substantially proved on the basis of the experimental results from a practical point of view.

A Single Active Edge-Resonant Snubber Cell-assisted ZCS Half-Bridge DC-DC Converter with Constant Frequency Asymmetrical PWM Scheme

Tomokazu Mishima, Mutsuo Nakaoka, Eiji Hiraki

2008 13TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE, VOLS 1-5 119 - + 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A newly-developed zero current soft-switching (ZCS)-PWM cell-assisted asymmetrical half-bridge (AHB) DC-DC converter topology with a high frequency (HF) link is presented in this paper. The soft-switching half-bridge DC-DC converter consists of a PWM-controlled single-ended half-bridge HF inverter and a center-tapped rectifier linked by a HF transformer. In order to attain the wide range of ZCS commutation in the primary-side HF inverter, the active edge resonant snubber cell composed of a switched capacitor and a lossless inductor is adopted in the half-bridge leg, providing ZCS commutation for a wide range of output power under constant switching frequency. The operation characteristics of the proposed DC-DC converter are described, and its feasibility data is demonstrated and evaluated with simulation and experimental results.

ZCSセルを用いたソフトスイッチングPWM-SEPP高周波インバータとIHクッキングヒータへの応用

三浦祐太, 藤田篤志, 大森英樹, 平木英治, 中岡睦雄

パワーエレクトロニクス学会誌 34 103 - 110 2008年

出版者・発行元：パワーエレクトロニクス学会

In this paper, multi-resonant zero current soft switching (ZCS) -PWM single ended push pull (SEPP) high frequency inverter is newly demonstrated for consumer induction heating (IH) appliances. The proposed inverter circuit has a novel ZCS cell consisting of high side main switch with lossless inductor snubber and active edge-resonant commutation cell (AERCC). The AERCC consisting of auxiliary diode, auxiliary resonant capacitor, auxiliary resonant inductor and auxiliary switch in parallel with the high side main switch arm. In the newly proposed inverter, heating power of IH cooking heater is controlled continuously during all heating power range under a principle of ZCS. The operating principle and performance analysis of the newly proposed inverter with asymmetrical pulse width modulation (PWM) control scheme are described using equivalent circuits in switching mode. This high frequency inverter can regulate heating power continuously from 0.25kW to 2.74kW in experiment with asymmetrical PWM control scheme. Finally, compared with conventional ZVS-PWM-SEPP high frequency inverter with asymmetrical PWM scheme, its power conversion efficiency of is high enough even in at low power range. The feasible effectiveness and practicability of the high frequency inverter treated here are substantially proved on the basis of experimental results for consumer IH cooking heater.

DOI： 10.5416/jipe2003.34.0_103

EPE-PEMC2008 (Poznan: Poland) 国際会議報告

平木英治

パワーエレクトロニクス学会誌 34 226 - 226 2008年

スタンドアローン駆動型太陽光発電システム用ソフトスイッチングコンバータ (第174回[パワーエレクトロニクス学会]定例研究会)

中山浩昭, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 34 143 - 150 2008年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

This paper deals with stand-alone photovoltaic (PV) generation systems low power DC applications, where a combined energy storage device consisting of an acid battery and Electric Double Layer Capacitor (EDLC) to avoid the deep discharge of the acid battery. Two types of the stand-alone PV generation systems, with a conventional converters and soft-switching converter, are constructed and tested. Experimental results demonstrate that the conventional type is very simple, but a large capacity EDLC is needed because of low efficiency. Efficiency of the PV generation system with soft-switching converters is high compared with that of the conventional type, and reduces the capacity of the EDLC. The PV generation system with soft-switching converters is useful for practical applications.

DOI： 10.5416/jipe2003.34.0_143

A Novel Simple Control Method of an Active Power Quality Compensator Used in Electrified Railways with Constant DC Voltage Control

T. Tanaka, N. Ishikura, E. Hiraki

IECON 2008: 34TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-5, PROCEEDINGS 451 - 456 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a novel and simple control method for an active power quality compensator (APQC) used in electrified railways. The proposed method consists of only constant dc capacitor voltage control, which is generally used in APQCs. No detection method for harmonic, reactive and negative-sequence components is necessary. Thus we offer the simplest way to compensate the harmonic, reactive and negative-sequence currents on the primary side of the Scott transformer in the traction substation. The basic principle of the proposed control method is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with unity power factor are obtained on the primary side with the proposed control method, which uses only constant dc capacitor voltage control.

DOI： 10.1109/IECON.2008.4758004

A novel half-bridge asymmetrical ZCS-PWM DC-DC converter with high frequency-link

Tomokazu Mishima, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

IEEJ Transactions on Industry Applications 128 ( 4 ) 5 - 395 2008年

記述言語：英語掲載種別：研究論文（学術雑誌）

A novel zero current soft-switching (ZCS)-PWM cell-assisted half-bridge DC-DC converter topology with a high frequency link is proposed in this paper. The newly-proposed DC-DC converter consists of a PWM-controlled singleended half-bridge high frequency (HF) inverter and a current doubler rectifier linked with a HF transformer. In order to attain the wide range of ZCS-PWM operation in the primary-side HF inverter, an active edge resonant snubber cell composed by a switched capacitor and a lossless inductor is adopted in the half-bridge leg, providing ZCS commutation for a wide range of output power. The operation characteristics of the DC-DC converter proposed here are described, and its feasibility data is demonstrated and evaluated with simulation and experimental results. © 2008 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejias.128.388

High-frequency link symmetrical active edge resonant snubbers-assisted ZCS-PWM DC-DC converter

T. Mishima, E. Hiraki, T. Tanaka, M. Nakaoka

IET ELECTRIC POWER APPLICATIONS 1 ( 6 ) 907 - 914 2007年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ENGINEERING TECHNOLOGY-IET

A novel symmetrical zero current switching (ZCS)-pulse width modulation (PWM) cells-assisted high-frequency transformer link DC-DC converter using insulated gate bipolar transistor (IGBT) modules is presented. The proposed soft switching scheme is based on the switched-capacitor and inductive snubber in the high-voltage side inverter, assisted by active switching of MOSFET synchronous rectifier in the secondary-side low-voltage converter stage. By introducing the ZCS-PWM snubber cells, soft switching commutation which is less sensitive to the current level through the IGBTs can be achieved under the wide output power ranges. The converter circuit topology and the ZCS snubber cell operation are examined and evaluated with simulation results, and the feasibility of the converter topology is verified by experiments using a 1.0 kW - 25 kHz prototype system.

DOI： 10.1049/iet-epa:20060508

A novel detection method of active and reactive currents in single-phase circuits using the correlation and cross-correlation coefficients and its applications

Toshihiko Tanaka, Eiji Hiraki, Kengo Ueda, Kuniaki Sato, Shinji Fukuma

IEEE TRANSACTIONS ON POWER DELIVERY 22 ( 4 ) 2450 - 2456 2007年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

This paper proposes a novel method of detecting the active and reactive currents in single-phase circuits using the correlation and cross-correlation coefficients in the time domain. The active current is detected using the correlation coefficient between the source voltage and load current waveforms, and the reactive current is detected using the cross-correlation coefficient. The basic principle of the proposed detection method is discussed, and the proposed method is applied to a previously proposed single-phase shunt active filter for consumer electronic equipment. Simulation and experimental results demonstrate the excellent practicability of the proposed detection method.

DOI： 10.1109/TPWRD.2007.905359

スーパーキャパシタインターフェイス用双方向絶縁形ソフトスイッチングDC-DCコンバータの特性評価

山本剛司, 平木英治, 田中俊彦, 三島智和

電子情報通信学会技術研究報告. EE, 電子通信エネルギー技術 107 ( 149 ) 21 - 26 2007年7月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

近年,人口増加に伴うエネルギー問題や環境保全といった地球問題から,電気自動車(EV)やハイブリッド自動車(HEV)の研究・開発が進められている。本論文では, EVやHEVの走行エネルギー回収用スーパーキャパシタ回生システムを想定したフルブリッジ-プッシュプル構成の双方向絶縁型ソフトスイッチングDC-DCコンバータを提案し,容量を低減した小型実験回路による基本的な特性評価を行った結果について報告している。

PLL回路を用いた単相回路における簡易な有効・無効電流検出法

大村泰, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 127 ( 5 ) 538 - 539 2007年5月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a novel detection method of active and reactive currents in single-phase circuits. This method uses only two multipliers and LPFs for detecting active and reactive currents with a PLL circuit. In the proposed method the fundamental active-reactive component in single-phase circuits can be detected by LPFs in the time domain like the instantaneous active-reactive power theory in three-phase circuits. The basic principle of the proposed detection method is discussed in detail, and then confirmed by digital computer simulation. Digital computer simulation results demonstrate that the proposed method can detect the active-reactive current in single-phase circuits in the time domain.

DOI： 10.1541/ieejias.127.538

改良型補助共振セルZCS-PWMDC-DCコンバータの動作特性 (第170回[パワーエレクトロニクス学会]定例研究会)

三島智和, 平木英治, 中岡睦雄

パワーエレクトロニクス学会誌 33 157 - 163 2007年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

A novel prototype of a soft-switching PWM DC-DC converter is presented in this paper. This converter consists of a half-bridge circuit assisted with an active edge resonant snubber for Zero Current Soft-switching (ZCS) commutation, and a current doubles rectifier linked with a high-frequency transformer. With the ZCS scheme and the circuit topology proposed here, the soft switching operation can be achieved for the wide range of output power under a constant switching frequency. The converter operation and characteristics are demonstrated with simulation results, and its feasibility is verified with experimental results using its 1.2kW-35kHz prototype.

DOI： 10.5416/jipe2003.33.0_157

スーパーキャパシタインターフェイス用双方向絶縁形ソフトスイッチングDC-DCコンバータの特性評価

山本剛司, 平木英治, 田中俊彦, 三島智和

電気学会研究会資料. SPC, 半導体電力変換研究会 2007 ( 74 ) 390 - 395 2007年

Operation analysis of a novel high frequency-link asymmetrical half-bridge ZCS-PWM DC-DC converter

Tomokazu Mishima, Eiji Hiraki, Toshihiko Tanaka, Khairy Fathy, Mutsuo Nakaoka

2007 POWER CONVERSION CONFERENCE - NAGOYA, VOLS 1-3 573 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A novel zero current soft-swithing PWM half-bridge DC-DC converter topology is proposed in this paper. The newly proposed converter consists of a PWM-controlled half-bridge inverter and a current doubler rectifier linked with a high-frequency transformer. In order to attain the wide range of soft switching operation in the high voltage/low current primary side inverter, asymmetrical lossless snubbers composed by an actively-switched capacitor and lossless inductors are employed in the half-bridge arm, providing Zero Current Switching (ZCS) that is less sensitive to the magnitude of the input current. The operation characteristics of the proposed DC-DC converter are described, and its feasibility is demonstrated with simulation and preliminary experimental results.

A novel low-voltage/high-current ZCS-PWM DC-DC converter with asymmetrical auxiliary edge-resonant lossless snubber

Tomokazu Mishima, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

2007 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-6 748 - 753 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE, ELECTRON DEVICES SOC & RELIABILITY GROUP

A novel zero current soft-switching PWM half-bridge DC-DC converter topology is proposed in this paper. The newly proposed converter consists of a PWM-controlled half-bridge inverter and a current doubler rectifier linked with a high-frequency transformer. In order to attain the wide range of soft switching operation in the high voltage/low current primary side inverter, asymmetrical lossless snubbers composed by an actively-switched capacitor and lossless inductors are employed in the half-bridge arm, providing Zero Current Switching (ZCS) that is less sensitive to the magnitude of the input current. The operation characteristics of the proposed DC-DC converter are described, and its feasibility is demonstrated with simulation and experimental results.

DOI： 10.1109/PESC.2007.4342081

電源電圧と負荷電流の相関に着目した単相三線式配電用電流バランサの制御法

田中俊彦, 福井博一, 平木英治, 渡邉修治, 福間慎治

電気学会論文誌. D, 産業応用部門誌 127 ( 6 ) 675 - 681 2007年

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new current balancer in single-phase three-wire secondary distribution systems using the correlation coefficients. The components of the load currents correlative to the primary side voltage waveform, which correspond to the active currents, are detected in each feeder, then the non-active and unbalanced-active components are compensated on the source side. The balanced currents with unity power factor are obtained in each feeder. The basic principle of the proposed method is discussed in detail, and then confirmed by digital computer simulation. A proto-type experimental system is constructed and tested. Experimental results demonstrate that the balanced source currents with unity power factor are obtained in spite of unbalanced load currents.

DOI： 10.1541/ieejias.127.675

A new phase shifted ZVS-PWM controlled full bridge series resonant high frequency inverter with auxiliary active quasi-resonant commutation circuit

Hisayuki Sugimura, Soon-Kurl Kwon, Hiroyuki Ogiwara, Eiji Hiraki, Mutsuo Nakaoka

2007 POWER CONVERSION CONFERENCE - NAGOYA, VOLS 1-3 1461 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents a novel phase shifted ZVS-PWM high frequency load resonant inverter for electromagnetic induction fluid heating (IH) appliances. The proposed high frequency inverter can be achieved stable and efficient zero voltage soft commutation over a widely specified power regulation range from full power to low power by using an active auxiliary quasi resonant snubber. The steady state operating performance of this inverter is evaluated and discussed on the basis of simulation and experimental results for IH dual-packs heater (DPH) of compact fluid heating appliance. Finally, the effectiveness of IH application of the proposed high frequency inverter with auxiliary active quasi-resonant snubber is demonstrated from the practical point of view.

A new current balancer for single-phase three-wire secondary distribution feeders using the correlation coefficients

Toshihiko Tanaka, Hirokazu Fukui, Eiji Hiraki

2007 POWER CONVERSION CONFERENCE - NAGOYA, VOLS 1-3 83 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new current balancer for single-phase three-wire distribution feeders using a three-leg voltage-source PWM inverter, which is equivalent to a three-phase voltage source inverter. Intelligent Power Modules (IPMs) can be used for the proposed current balancer. Thus we can provide a cost-effective and small-volume current balancer. A new control method for the proposed current balancer employing correlation coefficients between the source voltage and load currents is also proposed. The basic principle of the proposed current balancer with the proposed control method is discussed in detail, then confirmed by digital computer simulation with PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with unity power factor are obtained in spite of unbalanced load currents.

A new method of compensating harmonic currents for wind power generation systems with the soft starter using a hybrid active filter

Hiroaki Yamada, Miho Enami, Eiji Hiraki, Toshihiko Tanaka

2007 POWER CONVERSION CONFERENCE - NAGOYA, VOLS 1-3 382 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new method of compensating harmonic currents for wind power generation systems with the soft starter using a hybrid active filter. The hybrid active filter consists of single-tuned LC and small-rated active filters. The single-tuned LC filter absorbs the harmonic current while behaving as a phase-leading capacitor for the fundamental component. The small-rated active filter improves the compensation characteristics of the passive filter under the soft start of the constant-speed wind turbine. The required rating of the active filter can be reduced because the active filter does not supply the fundamental reactive current. The basic principle of the proposed compensation method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the waveform of the source current becomes sinusoidal under the soft start. The required rating of the active filter is about 8.5% of the induction generator rating. A new calculation method of THD with the detrending algorithm is proposed for the transient state. The THD of the source current is about 7.3% using the hybrid active filter.

Full bridge phase-shifted soft switching high-frequency inverter with boost PFC function for induction heating system

Yuki Kawaguchi, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

2007 EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS, VOLS 1-10 1647 - 1654 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE SERVICE CTR

This paper is mainly concerned with a high frequency soft-switching PWM inverter suitable for consumer induction heating system. Proposed system is composed of soft switching chopper based voltage boost PFC input stage and phase shifted PWM controlled full bridge ZCZVS high frequency inverter stage. Its fundamentals of operating performances are illustrated and evaluated on the experimental results. Its effectiveness is substantially proved on the basis of the experimental results from a practical point of view.

Direct high frequency soft switching inverter type AC-DC power converter with boost function for consumer magnetron drive

Mutsuo Nakaoka, Bishwajit Saha, Hisayuki Sugimura, Sang Pi Mun, Eiji Hiraki, Hideki Omori

IECON 2007: 33RD ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-3, CONFERENCE PROCEEDINGS 1336 - + 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The oscillation voltage (Ebm) is an important parameter of the characteristic constant of a high power microwave generator. When Ebm could he made hi-h. it serves so as to improve the power conversion efficiency of a magnetron. Thus, the newly developed magnetron with 7% higher oscillation cut-off voltage Than the present conventional one is manufactured by Matsushita Electric Industrial Co.Ltd, In addition to this, the utility AC power line current reduced harmonic type direct inverter AC-DC power converter suitable and acceptable for driving this Magnetron is proposed in this paper. This direct high frequency inverter type soft switching PWM AC-DC converter has the voltage-boost function based on active clamp scheme with soft switching pulse modulation strategy topology. This paper describes a novel type active clamp AC-DC power converter circuit defined as direct high frequency inverter and the switching operation of this power converter is described and discussed on the basis of simulation and experimental results. The operating characteristics of this soft switching direct high frequency inverter type AC-DC power converter using IGBTs that incorporates the harmonic current improvement as well as power factor correction are evaluated and discussed front a practical point of view as compared with the conventional AC-DC power converter.

DOI： 10.1109/IECON.2007.4459958

Direct high frequency soft switching PWM cyclo-converter-fed AC-DC converter without DC link for consumer magnetron drive

Hisayuki Sugimura, Bishwajit Saha, Sang Pil Mun, Eiji Hiraki, Hideki Omori, Mutsuo Nakaoka

7th Internatonal Conference on Power Electronics, ICPE'07 1185 - 1190 2007年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE Computer Society

The oscillation voltage (Ebm) is an important parameter of the characteristic constant of a high power microwave generator. When Ebm could be made high, it serves so as to improve the power conversion efficiency of a magnetron. Thus, the newly developed magnetron with 7% higher oscillation cut-off voltage than the present conventional one is manufactured by Matsushita Electric Industrial Co. Ltd, In addition to this, the utility AC power line current reduced harmonic type direct inverter AC-DC power converter suitable and acceptable for driving this magnetron is proposed in this paper. This direct high frequency inverter type soft switching PWM AC-DC converter has the voltage-boost function based on active clamp scheme with soft switching pulse modulation strategy topology. This paper describes a novel type active clamp AC-DC power converter circuit defined as direct high frequency inverter and the switching operation of this power converter is described and discussed on the basis of simulation and experimental results. The operating characteristics of this soft switching direct high frequency inverter type AC-DC power converter using IGBTs that incorporates the harmonic current improvement as well as power factor correction are evaluated and discussed from a practical point of view as compared with the conventional AC-DC power converter. © 2008 IEEE.

DOI： 10.1109/ICPE.2007.4692565

Newly proposed hybrid resonant commutation bridge-leg link snubber-assisted three-phase ZVZCS-PWM soft-switching inverter

Eiji Hiraki, Masanobu Yoshida, Yoshihiko Hirota, Mutsuo Nakaoka

ELECTRICAL ENGINEERING IN JAPAN 157 ( 4 ) 75 - 84 2006年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

This paper presents the newly proposed hybrid resonant commutation bridge-leg link (HRCB) snubber circuit which can achieve zero voltage and zero current soft-switching commutation for single-phase and three-phase voltage source-type inverter, along with its unique features and operation principle. The circuit parameter design approach for the HRCB snubber circuit and the determination estimating scheme of the gate pulse timing processing which is more suitable and acceptable for single-phase and space voltage vector modulated three-phase voltage source inverter using the HRCB snubber circuit are described in this paper. In particular, the three-phase voltage source soft-switching inverter associated with the proposed HRCB circuits are evaluated and discussed from simulation and experimental viewpoints. The practical effectiveness of the HRCB snubber-assisted three-phase voltage source soft-switching inverter using IGBT power modules which is based on the instantaneous space voltage vector modulation is clarified on the output voltage waveform, actual efficiency of electromagnetic noise in comparison with three-phase voltage source-type conventional hard-switching inverter. (C) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/eej.20111

ハイブリッドフィルタを用いたソフトスタータ付き風力発電システムの高調波電流補償法

山田洋明, 平木英治, 田中俊彦

電気学会研究会資料. SPC, 半導体電力変換研究会 2006 ( 87 ) 51 - 56 2006年6月

ハイブリッドフィルタを用いた風力発電システムのソフトスタート時における高調波電流補償法

山田洋明, 平木英治, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 126 ( 6 ) 818 - 819 2006年6月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new method of compensating harmonic currents under the soft start in wind power generation systems using the hybrid filter, which consists of a passive and small-rated active filters. For the fundamental component, the passive filter behaves a phase-leading capacitor. The small-rated active filter compensates the harmonic currents under the soft start. The basic principle of the proposed compensator is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the source currents become sinusoidal waveforms under the soft start.

DOI： 10.1541/ieejias.126.818

次世代自動車用スーパーキャパシタインターフェース双方向DC-DCコンバータ

三島智和, 平木英治, 山本剛司, 田中俊彦

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 126 ( 4 ) 529 - 530 2006年4月

記述言語：日本語出版者・発行元：一般社団法人電気学会

A bidirectional DC-DC converter for supercapacitor-based energy storage systems in advanced electric vehicles is proposed in this letter. This converter consists of a half-bridge and current-fed push-pull circuit linked with a high frequency transformer, which is well applicable to the low voltage/high current charge and discharge of the supercapacitor. The experimental results of the prototype system prove the effective properties of the proposed topology in terms of a low device-conduction loss and a low switching surge.

DOI： 10.1541/ieejias.126.529

新方式電圧給電フルブリッジ形ソフトスイッチングPWM高周波インバータを用いたアーク溶接機用高出力DC-DC変換器

森本慶樹, 土井敏光, 真鍋陽彦, AHMED Tarek, 平木英治, 李鉉雨, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 126 ( 3 ) 237 - 247 2006年3月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a new circuit topology of full-bridge soft-switching PWM inverter linked DC-DC power converter composed of conventional full-bridge high frequency PWM inverter with high frequency transformer and an active quasi-resonant snubber consisting of an additional power switching device in series with DC busline and a lossless capacitor in parallel with DC busline. Under this proposed high frequency soft-switching PWM inverter linked DC-DC converter, four power switches in the full-bridge arms and DC busline series switch can achieve ZVS at turn-off commutation. By developing the advanced soft-switching PWM high frequency inverter type DC-DC converter, although the conduction power loss of DC busline series power switch increases a little, the total turn-off switching loss of full-bridge high frequency inverter power modules can be sufficiently lowered more and more in the higher frequency range of 60kHz. As a result, when the switching frequency of high frequency inverter power stage using IGBT power modules is designed so as to be more than about 10kHz, the more the switching frequency of inverter increases, the more this high frequency soft-switching DC-DC converter has remarkable advantage as for the power conversion efficiency as compared with the conventional hard-switching PWM inverter DC-DC converter. Its practical effectiveness of high power density and high performance is actually proved for TIG arc welding equipment in industry.

DOI： 10.1541/ieejias.126.237

PFC機能を持つ三相AC-ACダイレクトインバータの特性評価

中尾昌弘, 平木英治, 田中俊彦, 中岡睦雄

電子情報通信学会技術研究報告. EE, 電子通信エネルギー技術 105 ( 601 ) 127 - 132 2006年2月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

近年,クリーン・急速加熱・高効率・安全性・温度制御容易といった優れた特徴を活かした電磁誘導加熱(IH)応用製品が家電分野や工業分野における電気エネルギー有効変換高度化利用分野で脚光を浴びている。本論文は高周波電磁誘導加熱用電力周波数変換器として低コスト・高効率・高入力力率・高パワー密度化が期待される商用周波AC-高周波ACソフトスイッチングPWMダイレクトコンバータを提案し,その動作原理と商用ACサイド高調波電流特性について検討している。

スーパーキャパシタインターフェース用ハーフブリッジ方式双方向DC-DCコンバータの検討

三島智和, 平木英治, 山本剛司, 田中俊彦

電気学会研究会資料. SPC, 半導体電力変換研究会 2006 ( 36 ) 25 - 28 2006年1月

相関関数を用いた単相三線式配電用電流バランサの制御法

田中俊彦, 福井博一, 平木英治, 渡邉修治, 福間慎治

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 126 ( 1 ) 84 - 85 2006年1月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper proposes a new control method of the current balancer in single-phase three-wire secondary distribution systems using the correlation function. The components of the load currents correlative to the primary side voltage waveform, which correspond to the active currents, are detected in each feeder, then the non-active and unbalanced-active components are compensated on the source side. The balanced currents with unity power factor are obtained in each feeder. The basic principle of the proposed method is discussed in detail, and then confirmed by digital computer simulation. Digital computer simulation results demonstrate that the balanced source currents with unity power factor are obtained in spite of unbalanced load currents.

DOI： 10.1541/ieejias.126.84

対称形ロスレススイッチトキャパシタスナバ方式ZCS双方向DC-DCコンバータ動作評価 (第164回[パワーエレクトロニクス学会]定例研究会)

三島智和, 平木英治, 田中俊彦

パワーエレクトロニクス学会誌 32 113 - 121 2006年

記述言語：日本語出版者・発行元：パワーエレクトロニクス学会

A new type of soft switched bidirectional DC-DC converter for advanced automotive electric power systems is presented in this paper. This converter consists of dual half-bridge circuits linked with a high frequency transformer, which is applicable as an interface between a high-voltage DC bus line and a low-voltage power source such as Supercapacitor. In order to reduce the switching losses and expand the soft switching range, a newly developed two-lossless switched capacitor snubber-assisted Zero Current Switching (ZCS) are applied to the primary side circuit. By using this ZCS scheme, the soft switching operation can be achieved for the wide range of output power. The converter operation is demonstrated with simulation results, and its feasibility is verified with experimental results using its 1.0kW 25kHz prototype system.

DOI： 10.5416/jipe2003.32.0_113

Bidirectional DC-DC converter with full-bridge/push-pull circuit for automobile electric power systems

Koji Yamamoto, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka, Tomokazu Mishima

2006 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-7 2340 - + 2006年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In recent years, energy storage systems assisted by super capacitor have been widely researched and developed to progress power systems for the electronic vehicles. In this paper, a full-bridge/push-pull circuit-based bidirectional DC-DC converter and its control methods are proposed. From the results of detailed experimental demonstration, the proposed system is able to perform adequate charge and discharge operation between low-voltage high-current super capacitor side and high-voltage low-current side with drive train and main battery. Furthermore, conduction losses and voltage/current surge are drastically reduced by ZVS operation with loss-less snubber capacitor in high voltage side as well as the synchronous rectification in low-voltage high-current super capacitor side.

A new soft-switched bidirectional DC-DC converter topology for automotive high voltage DC bus architectures

Tomokazu Mishima, Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

2006 IEEE VEHICLE POWER AND PROPULSION CONFERENCE 386 - + 2006年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A new type of soft switched bidirectional DC-DC converter for automotive electric power systems is presented in this paper. This converter consists of dual half-bridge circuits linked with a high frequency transformer, which is applicable as an interface between a high-voltage DC bus line and a low-voltage power source such as Supercapacitor. In order to reduce the switching losses and expand the soft switching range, a newly developed two-lossless switched capacitor snubber-assisted Zero Current Switching (ZCS) are applied to the primary side circuit. By using this ZCS scheme, the soft switching operation can be achieved for the wide range of output power. The converter operation is demonstrated with simulation results, and its feasibility is verified by experimental using its 1.0kW-25kHz prototype system.

An isolated bidirectional DC-DC converter based super-capacitor interface for automobile electric power systems

Eiji Hiraki, Koji Yamamoto, Toshihiko Tanaka, Tomokazu Mishima, Mutsuo Nakaoka

2006 12TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE, VOLS 1-4 1025 - + 2006年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In recent years, power electronic energy storage systems using super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge/centertapped push-pull circuit-based bidirectional DC-DC converter and its control method are proposed and discussed. From the results of detailed experimental demonstration, the proposed system is able to perform adequate charging and discharging operation between low-voltage high-current super capacitor side and high-voltage low-current side with drive train and main battery. Furthermore, conduction losses and voltage/current urge are drastically reduced by ZVS operation with lossless snubber capacitor in high-voltage side as well as the synchronous rectification in low-voltage high-current super capacitor side.

A ZCS lossless snubber cells-applied half-bridge bidirectional DC-DC converter for automotive electric power systems

Tomokazu Mishima, Eiji Hiraki, Toshihiko Tanaka

2006 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-7 917 - 922 2006年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A new type of bidirectional DC-DC converter for electric power systems in advanced electric vehicles is proposed in this paper. This converter consists of half-bridge circuits with a high frequency transformer, which is well applicable as an interface between a high-voltage DC bus line and a low-voltage power source. In order to reduce the switching loss, newly developed ZCS loss-less snubber cells are applied to the primary side power stage. By the proposed topology, a soft switching operation can be achieved under the wide range of load current. The converter operation is demonstrated with simulation results, and the feasibility of the new topology is discussed as well as the converter design consideration.

PLL回路を用いた単相回路における簡易な有効・無効電流検出法

松本脩平, 田中俊彦, 平木英治, 大村泰, 山本真義

パワーエレクトロニクス学会誌 32 192 - 192 2006年

A novel method of suppressing the inrush current of transformers using a series-connected voltage-source PWM converter 査読

Hiroaki Yamada, Eiji Hiraki, Toshihiko Tanaka

Proceedings of the International Conference on Power Electronics and Drive Systems 1 280 - 285 2005年12月

This paper proposes a novel method of suppressing the inrush current of transformers. A small-rated voltage-source PWM converter is connected in series to a transformer through a matching transformer. Since the connected PWM converter serves as a resistor for the source current, no inrush phenomenon occurs. The basic principle of the proposed method is discussed. Digital computer simulation is implemented to confirm the validity and excellent practicability of the proposed method using PSCAD/EMTDC. A prototype experimental model is constructed and tested. The experimental results demonstrate that the proposed method can perfectly suppress the inrush phenomena. The required-rating of the PWM converter, which acts as a damping resistor for the inrush phenomena, is about 0.25% of that of the main transformer in single-phase circuits, in the experimental results. In three-phase circuits, it is less than 0.1%. © 2005 IEEE.

相関関数を用いた単相三線式配電用電流バランサの制御法

福井博一, 渡辺修治, 平木英治, 田中俊彦

電気学会研究会資料. SPC, 半導体電力変換研究会 2005 ( 58 ) 13 - 18 2005年6月

Static VAR Compensator-Based Voltage Regulation for Variable-Speed Prime Mover Coupled Single-Phase Self-Excited Induction Generator

Ahmed Tarek, Noro Osamu, Hiraki Eiji, NAKAOKA Mutsuo

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 125 ( 4 ) 355 - 365 2005年4月

記述言語：英語出版者・発行元：The Institute of Electrical Engineers of Japan

In this paper, the single-phase static VAR compensator (SVC) is applied to regulate and stabilize smoothly the generated output voltage of the single-phase self-excited induction generator (single-phase SEIG) driven by a variable-speed prime mover (VSPM) under the conditions of inductive load variations and prime mover speed changes. The conventional fixed gain PI controller-based feedback control scheme is employed to adjust the equivalent capacitance of the single-phase SVC composed of the fixed excitation capacitor (FC) in parallel with the thyristor switched capacitor (TSC) and the thyristor controlled reactor TCR. A PI closed-loop feedback voltage control scheme based on the SVC for the single-phase SEIG coupled by a VSPM prototype set-up is established. The closed-loop feedback output voltage responses in the single-phase SEIG coupled by a VSPM with different inductive load variations using the single-phase SVC with the PI controller are considered and discussed herein. Based on the SVC with the PI controller closed-loop feedback voltage regulation scheme, the experimental results for the single-phase SEIG driven by a VSPM are illustrated and proved its practical effectiveness in terms of the fast response and the high performances.

DOI： 10.1541/ieejias.125.355

その他リンク： https://jlc.jst.go.jp/DN/JALC/00248680132?from=CiNii

直流平滑フィルタＤＣリンクをもたない高周波誘導加熱用ソフトスイッチングＰＷＭ電力周波数変換器

杉村央生, 村岡秀和, 平木英治, 弘田泉生, 安井健治, 大森英樹, Lee Hyun-Woo, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 125 ( 11 ) 988 - 999 2005年

記述言語：日本語出版者・発行元：一般社団法人電気学会

In this paper, high frequency power converter without DC smoothing electrolytic capacitor filter link which convert the 100V/200Vrms and 60Hz single phase utility frequency AC power into a high frequency AC. This proposed high frequency AC power converter without electrolytic capacitor filter can operate under a principle of soft switching PWM based on a lossless capacitor snubber is proposed and demonstrated for consumer high frequency induction heating (IH). In particular, this high frequency power converter capable of producing a high frequency AC more than 20kHz is developed for consumer IH applications as hot water producer and steamer based on the specially designed spiral type IH-Dual Packs Heater (DPH), which includes the dual mode pulse modulation control scheme based on soft switching PWM for high output power setting and commercial frequency AC zero voltage soft switching pulse density modulation (PDM) for low output power settings. This developed high frequency power frequency converter using trench gate IGBTs is clarified on the basis of experimental and simulation results for its circuit operation of the utility frequency AC to high frequency AC frequency PWM power converter without the electrolytic capacitor bank DC filter link for the IH hot water and IH steamer. These IH appliances are based upon an innovative electromagnetic IH-DPH for fluid heating as heat exchanger in consumer pipeline. Finally, its power regulation characteristics, power conversion efficiency and harmonic current components characteristics including power factor in utility AC grid side are evaluated and discussed from an experimental point of view. The practical effectiveness of this utility frequency AC to high frequency AC soft switching high power frequency converter defined conveniently as high frequency soft switching cyclo-inverter is proved as one of the important products effective for next generation IH application all electricity power utilizations.

DOI： 10.1541/ieejias.125.988

最新の小容量高周波スイッチング半導体電力変換器におけるパワーエレクトロニクス

平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 125 ( 11 ) 955 - 963 2005年

記述言語：日本語出版者・発行元：一般社団法人電気学会

In resent years, the soft switching commutated power converter technologies have attracted special interest in order to minimize semiconductor switching power losses and reduce conductive switching noise. This special issue deals with some schematic descriptions on application-specific quasi-resonant power converter circuits, which make use of soft switching commutation schemes.

DOI： 10.1541/ieejias.125.955

位相シフトPWM制御高周波インバータを用いたIHポーラス金属デュアルパックスヒータ方式給湯器の開発

藤田堅太郎, 杉村央生, 安井健治, 弘田泉生, 岩井利明, 大森英樹, 村岡秀和, 平木英治, 中岡睦雄

エレクトロヒート ( 140 ) 2005年

Consideration of time sharing output pulse pattern using instantaneous space voltage vector moderation for three-phase voltage source soft-switching inverter

M Yoshida, E Hiraki, M Nakaoka

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 88 ( 2 ) 34 - 40 2005年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SCRIPTA TECHNICA-JOHN WILEY & SONS

In this paper, we propose a single inductor type resonant AC link snubber as a technique for introducing soft-switching PWM technology into three-phase voltage source inverters and explain its circuit operation. We then explain the suitability of instantaneous space voltage vector sinewave modulation compared to sinewave-triangle wave relative modulation as the sinewave modulation technique of the soft-switching inverter introducing this resonant AC link snubber, and propose a time sharing pulse pattern based on the operating principle of this resonant AC link snubber. Furthermore, we discuss the limits on the widths of the pulses that can be output when the time sharing pulse output method is used and the soft-switching inverter performs sinewave modulation, and the need to correct narrow output pulse widths; describe in detail the relationship between the generation principle of the correction pulse pattern and the waveform distortion; and illustrate the simulation results when the minimum pulse width is corrected. Finally, we propose a new time sharing pulse pattern that does not nee the minimum pulse width correction by using the time sharing pulse pattern feature for the resonant AC link inverter and demonstrate its effectiveness from the simulation results for this output pulse pattern. (C) 2004 Wiley Periodicals, Inc.

Dual-mode time-sharing one-stage single-phase power conditioner using sinewave tracked soft switching PWM boost chopper

NA Ahmed, HW Lee, M Nakaoka, T Ahmed, E Hiraki, M Miyatake

CONFERENCE RECORD OF THE 2005 IEEE INDUSTRY APPLICATIONS CONFERENCE, VOLS 1-4 3 1612 - 1617 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

The paper presents a novel circuit topology of a high efficiency single-phase sinewave power conditioning and processing converter with a DC-link chemical capacitor. This power conditioner, used as a small scale stand-alone new-energy related power generation system, is composed of time-sharing operated sinewave absolute modulation boost chopper with a bypass diode in the first power processing stage and cascaded with a time-sharing sinewave pulse modulated full-bridge inverter as a second power processing stage operated by time-sharing dual mode pulse pattern control scheme. The unique operating principle of the power processing stage with the time-sharing dual mode sinewave modulation scheme is described with a simple design example. The paper provides and describes also a sinewave tracking voltage controlled soft switching PWM boost chopper with a passive auxiliary edge-resonant snubber. The new conceptual operating principle and the effectiveness of this novel one stage sinewave power conditioner related to new-energy generation system is reviewed through the experimental results.

New auxiliary active lossless snubber-assisted full bridge soft switching PWM high frequency inverter-fed DC-DC power converter

Tetsuya Etoh, Tarek Ahmed, Eiji Hiraki, Keiki Morimoto, Nabil A. Ahmed, Ki-Young Suh, Hyun Woo Lee, Mutsuo Nakaoka

ICEMS 2005: Proceedings of the Eighth International Conference on Electrical Machines and Systems 2 1090 - 1094 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE Computer Society

This paper deals with a novel full bridge circuit topology of high frequency transformer isolated soft switching PWM inverter type DC/DC power converter. The zero voltage soft switching PWM DC/DC power converter employing an input DC rail series switch and parallel capacitor assisted by high frequency transformer parasitic component is proposed and developed for high performance TIG and MIG arc welding in industry. Its operating principle in stead state is described by introducing switching mode equivalent circuits. The operating performances of 32V-300A/60kHz soft switching PWM inverter fed DC-DC power converter using IGBT module package are illustrated on the basis of experimental results along with its power loss analysis.

DOI： 10.1109/icems.2005.202715

Zero-voltage and zero-current soft - Switching PWM inverter

Eiji Hiraki, Toshihiko Tanaka, Mutsuo Nakaoka

2005 European Conference on Power Electronics and Applications 2005 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE Computer Society

This paper presents a zero-voltage and zero- current soft-switching (ZVZCS) PWM three phase inverter with a single auxiliary resonant commutation cell. All of the main switches in the three-phase inverter side can be turned on and turned off under zero-voltage and zero-current condition. The operating principle of proposed commutation cell is described, and the procedure to determine the optimum circuit parameters from the resonant equations is discussed. The performances of proposed ZVZCS three-phase inverter are discussed from the experimental and simulation points of view.

DOI： 10.1109/epe.2005.219661

三相電圧形圧正弦波ソトスイッチングインバータの瞬時空間電圧ベクトル変調法による出力電圧THDの改善

平木英治, 中岡睦雄

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 87 ( 5 ) 736 - 740 2004年5月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文は,アクティブ補助部分共振転流ブリッジレッグスナバ回路を用いた三相電圧形正弦波PWMソフトスイッチングインバータの変調法として瞬時空間電圧ベクトル変調法を取り上げ,補助共振転流回路部の動作時間が正弦波出力電圧波形の生成精度に与える悪影響及びその対策について考察した結果について述べる.

ZVZCS共振スナバとZVS共振スナバを用いたソフトスイッチングPWMインバータの電磁ノイズ評価と検討

吉田正伸, 広田慶彦, 平木英治, 中岡睦雄

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 87 ( 5 ) 726 - 732 2004年5月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では,三相電圧形インバータの高性能化・高効率化・低電磁ノイズ化の実現のために,部分共振転流スナバ回路を用いたソフトスイッチングPWMインバータを取り上げている.まず,従来のZVS(ゼロ電圧スイッチング)-PWMインバータの一回路方式として共振ACリンクスナバ方式ZVS-PWM三相電圧形インバータを提案し,その回路動作を説明している.次に共振ACリンクスナバ方式ZVS-PWMインバータの伝導性コモンモードノイズとノーマルモードノイズを直流入力バスラインに接続した擬似電源回路網とスペクトルアナライザを用いて測定している.その測定結果よりZVS-PWMインバータでは従来ハードスイッチングインバータに対してコモンモードノイズの低減効果がある一方でノーマルモードノイズが低減できていないことを指摘している.次に,インバータ主スイッチをZVSかつZCS(ゼロ電流スイッチング)動作可能な複合共振ブリッジレッグリンクスナバ方式(Hybrid Resonant Commutation Bridge Leg Link Snubber : HRCB)のZVZCS-PWM三相電圧形インバータを提案し,その回路構成と動作原理を説明している.更にZVZCS-PWMインバータにおいて,伝導性電磁ノイズ評価を行い,コモンモードノイズだけでなくノーマルモードノイズも従来ハードスイッチングPWMインバータと比べて低減できることを示している.最後にZVS-PWMインバータとZVZCS-PWMインバータの伝導性電磁ノイズ測定結果より,インバータ主スイッチにおけるZVSかつZCSの完全なソフトスイッチング動作によって,コモンモード及びノーマルモード双方の伝導性電磁ノイズの低減手法として有効であることを明らかにしている.

高出力マグネトロン駆動用高周波高電圧トランスリンク直列共振形ZCS-PFM制御DC-DCコンバータ

石飛学, 苗井健, 宗進耕児, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 124 ( 4 ) 352 - 359 2004年4月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a single lossless inductive snubber-assisted ZCS-PFM series resonant DC-DC power converter with a high-frequency high-voltage transformer link for industrial-use high power magnetron drive. The current flowing through the active power switches rises gradually at a turned-on transient state with the aid of a single lossless snubber inductor, and ZCS turn-on commutation based on overlapping current can be achieved in wide range pulse frequency modulation control scheme. The high-frequency high-voltage transformer primary side resonant current always becomes continuous operation mode, by electromagnetic loose coupling design of the high-frequency high-voltage transformer and the magnetizing inductance of the high-frequency high-voltage transformer. As a result, this high-voltage power converter circuit for the magnetron is possible to achieve a complete zero current soft switching under a condition of the broad width gate voltage signals. Furthermore, this high-voltage DC-DC power converter circuit can regulate the output power from zero to full over audible frequency range because of two resonant frequency circuit design. Its operating performances are evaluated and discussed on the basis of the power loss analysis simulation and the experimental results from a practical point of view.

DOI： 10.1541/ieejias.124.352

新型複合共振転流ブリッジレッグリンクスナバを用いた三相電圧形ZVZCS-PWMインバータと実証評価

平木英治, 吉田正伸, 広田慶彦, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 124 ( 3 ) 286 - 294 2004年3月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents the newly-proposed hybrid resonant commutation bridge leg link (HRCB) snubber circuit which can achieve zero voltage and zero current soft-switching commutation for single-phase and three-phase voltage source-type inverter, along with its unique features and operation principle. The circuit parameter design approach for the HRCB snubber circuit and the determination estimating scheme of the gate pulse timing processing which is more suitable and acceptable for single-phase and space voltage vector modulated three-phase voltage source inverter using the HRCB snubber circuit are described in this paper. In particular the three-phase voltage source soft-switching inverter associated with the proposed HRCB circuits are evaluated and discussed from simulation and experimental viewpoint. The practical effectiveness of the HRCB snubber-assisted three-phase voltage source soft-switching inverter using IGBT power modules which is based on the instantaneous space voltage vector modulation is clarified on the output voltage waveform, actual efficiency and electromagnetic noises in comparison with three-phase voltage source-type conventional hard-switching inverter.

DOI： 10.1541/ieejias.124.286

Static VAR compensator-based terminal voltage regulation scheme of self-excited induction generator driven by variable speed prime mover for clean renewable energy utilizations

Tarek Ahmed, Eiji Hiraki, Mutsuo Nakaoka, Osamu Noro

Conference Proceedings - IPEMC 2004: 4th International Power Electronics and Motion Control Conference 3 1219 - 1224 2004年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, the steady-state analysis of the three-phase self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) such as a wind turbine is presented. The steady-state torque-speed characteristics of the VSPM are considered with the three-phase SEIG equivalent circuit for evaluating the operating performances due to the inductive load variations. Furthermore, a PI closed-loop feedback voltage regulation scheme based on the static VAR compensator (SVC) for the three-phase SEIG driven by the VSPM is designed and considered for the wind power generation conditioner. The simulation and experimental results prove the practical effectiveness of the additional SVC with the PI controller-based feedback loop in terms of high performances with low cost.

A novel soft switching PWM sinewave converter with regenerative pulse current edge-resonant snubber power modules for distributed power supplies

Mantaru Nakamura, Tarek Ahmed, Eiji Hiraki, Mutsuo Nakaoka

IEE Conference Publication 1 203 - 208 2004年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, a novel circuit topology of the active auxiliary edge resonant snubber suitable and acceptable for high power soft switching inverter and rectifier applications which includes some salient features as compared with conventional active auxiliary resonant commutation pole snubber is proposed newly. This resonant snubber circuit can minimize the switching power losses of power semiconductor devices (IGBTs), switching voltage and current surges, high frequency leakage currents to the heat sink in addition to the switching surge related electromagnetic noises in high power conversion conditioning and processing circuits on the basis of the voltage source type sinewave PWM inverter and voltage source sinewave PWM PFC converter as well as bi-directional PWM converter interfaced the battery energy storage system. This resonant snubber-assisted inverter and rectifier for high power conversion is described and discussed on the basis of soft switching transition and commutation operation of the voltage source type high efficiency pulse modulated inverter. The operation principle and operating characteristics of this active auxiliary snubber circuit are respectively described, together with the practical design procedure of this unique edge auxiliary snubber. Furthermore, the three-phase soft switching sinewave PWM inverter with the novel auxiliary active edge resonant bridge leg link snubbers treated here is implemented and discussed as compared with three phase hard switching sinewave PWM inverter, along with the practical evaluations bi-directional double converter for UPS system. © 2004 Yamaguchi University, Japan.

新電圧ベクトル変調パルスパターン制御3レベル三相電圧形ソフトスイッチングインバータ

山本真義, 佐藤伸二, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 12 ) 1397 - 1405 2003年12月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a novel prototype of 3-level 3-phase voltage-fed soft switching commutation inverter with two Active Auxiliary Resonant DC Link (ARDCL) snubbers which can operate under a condition of Zero Voltage Switching (ZVS) transition. Its operating principle is described herein. The feasible steady-state performances of the proposed soft switching commutated inverter using the latest IGBTs such as planner type and trench type IGBTs, which is more suitable for power systems applications, are evaluated and discussed on the basis of its experimental results and simulation ones.

DOI： 10.1541/ieejias.123.1397

2次側アシストソフトスイッチング高周波リンクPWM DC/DCコンバータ

佐藤伸二, モイセエフセルゲイ, 石飛学, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 12 ) 1414 - 1421 2003年12月

記述言語：日本語出版者・発行元：一般社団法人電気学会

Advanced development of the high frequency pulse modulated DC/DC power converters are indispensable in order to achieve smaller size, higher performances of the power supplies. In resent years the problems of the electromagnetic noise generation caused by the hard-switching pulse width modulation (PWM)—based high frequency operation of the switching power devices have been significant, including switching losses and switching surges. As result a variety of soft-switching power conversion circuit technologies have been attracted special interests for reducing switching power losses and minimizing electromagnetic interference. The soft-switching pulse modulation of DC/DC power circuit topologies can be divided into continuous current mode resonant type and quasi-resonant voltage mode type. The soft-switching DC/DC converters, a continuous current mode zero current soft-switching (ZCS) DC/DC converter with pulse frequency modulation (PFM) has been already put into a practical use. In this sort of power converters soft-switching commutation can be achieved over wide load variation ranges and high stability can be also performed, but high current peak stress through power semiconductor devices arises, however, and it causes relatively large increase of conduction power losses in the power semiconductor devices, high frequency transformers as well as rectifier diodes. As a result, the problem of a high efficiency for DC/DC power converter could not still unsolved.<br>Thereupon, in this paper, quasi-resonant voltage mode based soft-switching PWM DC/DC power converter with a high frequency transformer link is presented, which has on/off assisted synchronous rectifier in its secondary side. The PWM operation of this converter is described in comparison with conventional one. Due to using power MOSFET as on/off assisted synchronous rectifier in the secondary side of the high frequency isolated transformer, it is possible to achieve stable zero voltage soft-switching (ZVS) conditions from no load to the rated load for minimum requirement of a magnetizing current. As result of a high value of the magnetizing inductance design, the power converter actual efficiency of this converter can be designed so as to above 97% in experiment. Moreover, results of a switching losses analysis are discussed from an experimental point of views in this paper. The effectiveness of the power converter treated hare is proved from a practical point of view by using 32kHz-2.5kW breadboard setup.

DOI： 10.1541/ieejias.123.1414

瞬時空間電圧ベクトル正弦波変調3相電圧形ソフトスイッチングインバータの時分割出力パルスパターンと波形生成精度に関する考察

吉田正伸, 平木英治, 中岡睦雄

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 86 ( 11 ) 2417 - 2422 2003年11月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では,3相電圧形インバータヘのソフトスイッチングPWM技術導入の一手法として共振インダクタ一括形共振ACリンクスナバ回路を提案しその回路動作について述べている.次に,本共振ACリンクスナバ回路を導入したソフトスイッチングインバータの正弦波変調法として瞬時空間電圧ベクトル正弦波変調が正弦波三角波比較変調方式に比べて適していることを説明し,本共振ACリンクスナバ回路の動作原理に基づいた時分割パルスパターンについて提案している.更に,時分割パルス出力法を用いてソフトスイッチングインバータを正弦波変調した場合には出力可能なパルス幅に制限があり,短い出力パルス幅の場合には補正が必要であることを言及し,補正パルスパターンの発生原理と波形ひずみの関係について詳述し,最小パルス幅補正を行った際のシミュレーション解析結果を図示している.最後に本共振ACリンクインバータに対して,その時分割パルスパターンの特徴を利用した最小パルス幅補正の必要のない時分割パルスパターンを新しく提案し,その出力パルスパターンに対してシミュレーション解析を行った結果からその有効性を明らかにしている.

一括インダクタ形共振ACリンクスナバを用いた三相電圧形ソフトスイッチングインバータの性能評価

吉田正伸, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 11 ) 1269 - 1275 2003年11月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a novel three-phase voltage source type soft-switching inverter using the main and auxiliary IGBT power module packages in order to reduce their switching power losses as well as its electromagnetic noises. A single inductor-assisted resonant AC link snubber circuit as one of some resonant snubbers to achieve the zero voltage soft-switching for the three-phase voltage source inverter (VSI) with instantaneous space voltage vector sinewave modulation strategy is originally demonstrated as compared with the other resonant AC link snubber circuit topologies. In addition to this, its operation principle and unique features are described in this paper for resistive and inductive loads. Furthermore, the practical basic operating performances of the new instananeous space vector modulated soft-switching VSI using IGBT power modules are evaluated and discussed on the basis of power conversion efficiency and electromagnetic conductive and radiative noises from an experimental point of view, as compared with those of hard-switching VSI.

DOI： 10.1541/ieejias.123.1269

MRI傾斜磁場発生用多並列ブリッジ電流増幅器とディジタル最適制御設計法

渡辺修治, 高野博司, 福田博也, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 8 ) 894 - 902 2003年8月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper deals with a digital control scheme of multiple paralleled high frequency switching current amplifier with four-quadrant chopper for generating gradient magnetic fields in MRI (Magnetic Resonance Imaging) systems. In order to track high precise current pattern in Gradient Coils (GC), the proposal current amplifier cancels the switching current ripples in GC with each other and designed optimum switching gate pulse patterns without influences of the large filter current ripple amplitude. The optimal control implementation and the linear control theory in GC current amplifiers have affinity to each other with excellent characteristics. The digital control system can be realized easily through the digital control implementation, DSPs or microprocessors. Multiple-parallel operational microprocessors realize two or higher paralleled GC current pattern tracking amplifier with optimal control design and excellent results are given for improving the image quality of MRI systems.

DOI： 10.1541/ieejias.123.894

2石補助共振DCリンクスナバを用いた三相電圧形ソフトスイッチングPWMインバータの直流電圧利用率改善

長井真一郎, 佐藤伸二, 山本真義, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 6 ) 710 - 716 2003年6月

記述言語：日本語出版者・発行元：一般社団法人電気学会

In recent years, a resonant snubber to minimize switching power losses and EMI noises have attracted special interest for the voltage-fed soft switching sinewave PWM inverters and active rectifiers. The authors have discussed the performance evaluations on lower noise and high efficiency for two switch auxiliary resonant DC link snubber assisted three-phase voltage-fed soft switching PWM inverter. It was proved that cost effective three phase soft switching inverter treated here is able to improve both efficiency and EMI noise. However, some practical problems to be improved have recognized for the soft-switching three phase PWM inverter treated here from a practical point of view. This three phase soft-switching inverter with two switch type auxiliary resonant DC link snubber has significant disadvantages of DC busline link voltage reduction for the existence of the zero voltage mode transition period as well as the larger size and physical volume of electrolytic capacitor incorporated into the resonant DC link snubber. The additional technology to minimize the busline DC link zero voltage period in order to overcome the practical problems mentioned above is newly proposed in this paper. From experimental and simulation viewpoints, the modified version of this soft-switching inverter is discussed and evaluated for the DC busline voltage utilization factor as compared with the previously developed one.

DOI： 10.1541/ieejias.123.710

デュアルモードPFM直列共振ZCS高周波インバータを用いた多倍圧整流コンバータの過渡・定常特性改善

〓恩輝, ガマゲラクナース, 石飛学, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 6 ) 649 - 659 2003年6月

記述言語：日本語出版者・発行元：一般社団法人電気学会

The A variety of switched-mode high voltage DC power supplies using voltage-fed type or current-fed type high-frequency transformer resonant inverters using MOS gate bipolar power transistors; IGBTs have been recently developed so far for a medical-use X-ray high power generator. In general, the high voltage high power X-ray generator using voltage-fed high frequency inverter with a high voltage transformer link has to meet some performances such as (i) short rising period in start transient of X-ray tube voltage (ii) no overshoot transient response in tube voltage, (iii) minimized voltage ripple in periodic steady-state under extremely wide load variations and filament heater current fluctuation conditions of the X-ray tube. <BR>This paper presents two lossless inductor snubber-assisted series resonant zero current soft switching high-frequency inverter using a diode-capacitor ladder type voltage multiplier called Cockcroft-Walton circuit, which is effectively implemented for a high DC voltage X-ray power generator. This DC high voltage generator which incorporates pulse frequency modulated series resonant inverter using IGBT power module packages is based on the operation principle of zero current soft switching commutation scheme under discontinuous resonant current and continuous resonant current transition modes. This series capacitor compensated for transformer resonant power converter with a high frequency transformer linked voltage boost multiplier can efficiently work a novel selectively-changed dual mode PFM control scheme in order to improve the start transient and steady-state response characteristics and can completely achieve stable zero current soft switching commutation tube filament current dependent for wide load parameter setting values with the aid of two lossless inductor snubbers. It is proved on the basis of simulation and experimental results in which a simple and low cost control implementation based on selectively-changed dual-mode PFM for high-voltage X-ray DC-DC power converter with a voltage multiplier strategy has some specified voltage pattern tracking voltage response performances under rapid rising time and no overshoot in start transient tube voltage as well as the minimized steady-state voltage ripple in tube voltage.

DOI： 10.1541/ieejias.123.649

高昇圧変換比をもつゼロ電圧ソフトスイッチング高周波PWM昇圧チョッパ形DC-DCコンバータ

イナバクラウジオユウジ, 小西義弘, 平木英治, 中岡睦雄

電子情報通信学会論文誌. B, 通信 = The transactions of the Institute of Electronics, Information and Communication Engineers. B 86 ( 3 ) 599 - 603 2003年3月

2相並列高周波PWMチョッパ形電力増幅器を用いた傾斜磁場電流マルチループフィードバック追従制御

渡辺修治, 高野博司, 福田博也, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 123 ( 3 ) 188 - 195 2003年3月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper deals the digital optimal current control scheme to improve MRI (Magnetic Resonant Imaging) Gradient-Magnetic Coil (GC) current control implementation. The GC current needs high precision control specifications so as to take clear images with MRI. The novel MRI-GC current control amplifier has the high-frequency PWM chopper circuit with a multi-parallel input structure. The GC current control circuit can prevent the current ripple amplitude and realize high precision GC current controls, but the control system is hard to design because the GC current control circuit has the multi-input and multi-output structure and required high precision control abilities. Therefore, the digital optimal control scheme has tried to apply for the GC current control. The optimal controller is skillful at the design of multi-input and multi-output systems. The novel controller will actualize the high precision GC current controllability because Error System newly includes the GC current error parameter so as to decide the multi-inputs. In this paper, we discuss the novel controller with computer simulations that it can expect the high precision GC current control to improve the image quality of MRI systems.

DOI： 10.1541/ieejias.123.188

共振開始初期電流を必要としないアクティブ補助共振転流スナバを用いたインバータの性能評価

中村萬太郎, 山崎貴幸, Chandhaket Srawouth, AHMED Tarek, 平木英治, 中岡睦雄

電子情報通信学会技術研究報告. EE, 電子通信エネルギー技術 102 ( 643 ) 31 - 36 2003年2月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では、無停電電源、電力系統連系分散型燃料電池発電電源、マイクロガスタービン・風力タービン駆動発電装置、電気鉄道補助電源、アクティブパワーフィルタなど各種の電圧形インバータ応用装置として、補助スイッチを持つアクティブ補助共振スナバを用いた新方式部分共振PWMブリッジインバータを新提案し、そのソフトスイッチングパルス変調(PWM)方式並びに補助共振スナバ回路の最適設計条件について述べている。すなわち本ソフトスイッチングPWMインバータ方式は主スイッチの他に補助スイッチを含む部分共振スナバ回路が必要であるが、主スイッチおよび補助スイッチともにZVSまたはZCSによるソフトスイッチングを実現し、各スイッチのスイッチング損失の低減とインバータのノイズの低減が可能となる方式である。本電圧形インバータ回路の補助スイッチと共振スナバ回路は主スイッチがスイッチング動作する時点のみ働き、その最適回路設計をすることにより補助スイッチおよび共振スナバ回路の電流値を負荷電流値レベルに押さえることが可能である他、かつスイッチング時の電圧または電流の立上り立下り時間を設定することもできる。また本回路方式においてはソフトスイッチング動作を行うために特別の電圧または電流の検出回路を含むシステムの制御に持ち込む必要がない。この回路方式は直流電源の中点電位を必要としない。一般のソフトスイッチングPWM技術と同様であるが、パワー半導体スイッチのスイッチング時間特性と導通時の飽和電圧降下特性にトレードオフの関係があるため、飽和電圧降下特性の改善に特化したパワー半導体スイッチ(IGBT)を適用すれば一層の効率向上が可能となることを言及している。

高周波共振型インバータを用いた液晶バックライト誘電体バリア放電ランプの性能評価

藤田堅太郎, 谷松弘章, Gamage Laknath, 村岡秀和, 平木英治, 中岡睦雄

照明学会全国大会講演論文集 36 17 - 17 2003年

記述言語：日本語出版者・発行元：一般社団法人照明学会

液晶バックライト用ランプとしてＣＣＦＬ（冷陰極蛍光ランプ）が幅広く用いられている。環境リサイクルの点から水銀フリーが要求され、液晶バックライト用として注目されている。誘電体バリヤ放電ランプの電気回路モデル（非線形容量モデル）を提示し、その定数測定法を明らかにする。次に、ローコスト・高効率電圧共振型インバータを用いて誘電体バリヤ放電ランプを駆動させたときの特性について述べている。さらに、調光制御としてパルス密度変調方式を導入しその有効性を述べている。本文の内容としては、（１）誘電体バリヤ放電ランプの構造と電気的等価回路、（２）電気回路のパラメータの測定法と数値例、（３）一石電圧共振型高周波インバータ、（４）パルス密度変調による出力変調と特徴、（５）電流共振型インバータとパルス密度変調制御、（６）性能評価と実証的検討、（７）まとめ、（８）改良型電圧共振型高周波インバータの導入と将来動向という構成で発表を行う。

DOI： 10.11515/ieijac.36.0.17.0

共振ACリンクスナバ方式三相電圧形インバータの伝導性・放射性電磁ノイズ評価と検討

吉田正伸, 平木英治, 中岡睦雄, 篠原貞夫, 古川勝彦

電気学会全国大会講演論文集 2003 ( 4 ) 2003年

マグネトロン駆動用高周波高電圧トランスリンク電流形ZVS-PFM DC-DC電力変換器と特性評価

石飛学, 苗井健, 平木英治, 中岡睦雄

パワーエレクトロニクス学会誌 29 ( 2 ) 48 - 53 2003年

出版者・発行元：パワーエレクトロニクス学会

We have considered a voltage-source type series-resonant ZCS-PFM DC-DC Converter in order to drive an industrial-use magnetron for generating high power microwave in advance. This DC-DC converter can achieve a complete zero current soft switching by assist of the transformer parasitic parameter and a lossless inductive snubber. And the output power is regulated over all power ranges without audible frequency range due to the magnetizing current of the high-frequency transformer. However, this DC-DC converter has a weak point that it is easy to oscillate by the parasitic capacitance of the switching device and the lossless inductive snubber. Therefore in this paper, the new topology that can solve that weak point without hurting good characteristics of that converter is proposed and evaluated on the basis of simulation and experimental results.

DOI： 10.5416/jipe2003.29.2_48

系統連系高周波2石フライバックトランス絶縁方式ソフトスイッチングPWM正弦波インバータ

チャンタケートサラウット, 小西義弘, 小倉弘毅, 平木英治, 中岡睦雄

パワーエレクトロニクス学会誌 29 ( 2 ) 54 - 61 2003年

出版者・発行元：パワーエレクトロニクス学会

This paper presents two novel prototypes of the utility AC power source connected sinewave inverter using the high-frequency two-switch flyback transformer which is more suitable and acceptable for the small-scale solar photovoltaic and fuel cell generator interfaced power conditioners. The proposed sinewave soft-switching PWM power conditioner with a high-frequency AC link has a function of electrical isolation including sinewave hard-switching PWM power conditioner with a high frequency link, which is considered for solar photovoltaic power conditioner and fuel cell generator related power conditioner from the viewpoints of safety and reliability in total system. The discontinuous conduction mode (DCM) operation of the flyback transformer in this circuit system is also introduced to feature a simple, low-cost and high-efficiency topology of the sinewave inverter circuit and digital control implementation. The operating principle of the proposed sinewave soft-switching PWM inverter circuit as compared with sinewave hard-switching PWM inverter are described for the designing of circuit parameters. Moreover, the digitally controlled sinewave PWM control processing scheme is presented herein. Finally, the sinewave soft-switching PWM inverter prototype is actually built and tested to verify the validity of the proposed power conditioner for new energy generation systems.

DOI： 10.5416/jipe2003.29.2_54

高周波リンク電流形ZVS-PFM並列共振DC/DCコンバータ

苗井健, 石飛学, GAMAGE L, 平木英治, 中岡睦雄

電気学会半導体電力変換研究会資料 SPC-03 ( 25-28.30-36 ) 2003年

三相電圧形ZVZCS-PWMインバータの特性評価と検討

吉田正伸, 藤井勇馬, 平木英治, 中岡睦雄

電気学会産業応用部門大会講演論文集 2003 ( 1 ) 2003年

昇圧チョッパ型入力段を持つ三相電圧形ソフトスイッチングインバータの電力変換効率推定

平木英治, 吉田正伸, 中岡睦雄

電気学会全国大会講演論文集 2003 ( 4 ) 2003年

ZCS&ZVS補助共振レッグリング形インバータとその実証評価

広田慶彦, 吉田正伸, 平木英治, 中岡睦雄, 篠原貞夫, 古川勝彦

電気学会半導体電力変換研究会資料 SPC-03 ( 25-28.30-36 ) 2003年

パルス密度変調制御負荷共振形高周波インバータと新しい応用

GAMAGE L, 松田樹也, 村岡秀和, 平木英治, 中岡睦雄

電気学会半導体電力変換研究会資料 SPC-03 ( 150-152.154-161 ) 2003年

新しい共振スナバを持つ三相正弦波ZVS-PWMインバータ

中村万太郎, 白石和洋, 今村公輔, AHMED T, 平木英治, 中岡睦雄

電気学会半導体電力変換研究会資料 SPC-03 ( 134-149 ) 2003年

直流昇圧型ソフトスイッチングPWMチョッパの電磁ノイズ評価

小倉弘毅, CHANDHAKET S, AHMED T, 平木英治, 中岡睦雄

電気学会半導体電力変換研究会資料 SPC-03 ( 104-110 ) 2003年

ブリッジ形共振ACリンクスナバを用いた三相電圧形インバータと性能評価

伊与森尚, 吉田正伸, 長井真一郎, 平木英治, 中岡睦雄

電気学会全国大会講演論文集 2003 ( 4 ) 2003年

Three-phase power module bridge type auxiliary resonant AC link snubber-assisted three-phase soft switching inverter 査読

H Iyomori, S Nagai, M Yoshida, E Hiraki, M Nakaoka

IECON'03: THE 29TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1 - 3, PROCEEDINGS 2705 - 2710 2003年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents, a novel prototype of the three-phase power module bridge package type auxiliary resonant AC link snubber circuit for the three-phase voltage source type sinwave soft switching PWM inverter using IGBT power module which operates under instantaneous space voltage vector modulation scheme. The operating principle of a novel prototype resonant AC link snubber circuit in addition to its unique features are described for current source load model during one switching period which is equivalent to the three-phase voltage source type inverter with LPF, along with its design approach based on the simulation data. The steady-state performance evaluations of space vector modulated three-phase voltage source type sinewave soft switching inverter incorporating a new prototype circuit of three-phase active auxiliary resonant AC link snubber is illustrated and discussed as compared with those of three-phase voltage source type sinewave hard switching PWM inverter with a space voltage vector modulation strategy. The power loss analysis of the three-phase soft switching PWM inverter using IGBT power modules is actually evaluated and discussed on the basis of the conduction power losses based upon the measured v-i characteristics in addition to all the switching power losses of each IGBT with antiparallel diode.

Small-scale wind turbine coupled single-phase self-excited induction generator with SVC for isolated renewable energy utilization

T. Ahmed, K. Ogura, K. Soshin, E. Hiraki, M. Nakaoka

Proceedings of the International Conference on Power Electronics and Drive Systems 1 781 - 786 2003年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Institute of Electrical and Electronics Engineers Inc.

In this paper, the static VAR compensator (SVC) composed of the fixed excitation capacitor(FC) in parallel with the thyristor switched capacitor (TSC) and the thyristor controlled reactor (TCR) is applied to regulate and stabilize the generated terminal voltage of the single-phase self-excited induction generator (SEIG) for the passive load variations and the prime mover speed changes. The conventional fixed gain PI controller is employed to adjust the equivalent capacitance of the single-phase SVC in the output of the single-phase SEIG. The closed-loop terminal voltage responses due to different inductive passive load disturbances in the single-phase SEIG using the single-phase SVC with the PI controller are considered and discussed herein. A prototype setup for the single-phase SEIG with SVC voltage regulation feedback control scheme is implemented. The experimental results of this power conditioner are illustrated and give good agreements with the digital simulation results.

DOI： 10.1109/PEDS.2003.1283003

A sinusoidal pulse width modulated inverter using three-winding high-frequency flyback transformer for PV power conditioner

S. Chandhaket, Y. Konishi, K. Ogura, E. Hiraki, M. Nakaoka

PESC Record - IEEE Annual Power Electronics Specialists Conference 3 1197 - 1201 2003年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents a novel prototype of the utility-interfacing sinusoidal pulse width modulation (SPWM) inverter using the high-frequency flyback transformer for the small-scale solar photovoltaic power conditioner (1kW - 4kW). The proposed SPWM power conditioner circuit with a high-frequency link has a function of electrical isolation, which is vital for PV power conditioner systems with the viewpoint of safety, noise requirement and convenience. The discontinuous conduction mode (DCM) operation of the flyback transformer link pulse modulation is also introduced to establish a simple topology of the inverter circuit and control scheme. The proposed PV power conditioner operates with ZVS when it turns off the primary-side switches by the high-frequency switching. This reduces the power losses of the semi-conductor device switchings and improves the power conversion efficiency of the total system as PV power processor. The operating principle of the proposed circuit is described for the understanding of the circuit parameters establishment Then, the digital control scheme is demonstrated herein. The proposed power conditioner is verified on the basis of the computer simulations and experiments. The experimented results show the validity of the proposed power conditioner to have high power conversion efficiency and low harmonic distortions.

Three-Phase Self-Excited Induction Generator Driven by Variable-Speed Prime Mover for Clean Renewable Energy Utilizations and Its Terminal Voltage Regulation Characteristics by Static VAR Compensator

Tarek Ahmed, Eiji Hiraki, Mutsuo Nakaoka, Osamu Noro

Conference Record - IAS Annual Meeting (IEEE Industry Applications Society) 2 693 - 700 2003年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, the practical impedance approach steady-state analysis in the frequency domain of the three-phase self-excited induction generator (SEIG) with squirrel cage rotor is presented along with its operating performance evaluations. The three-phase SEIG is driven by a variable-speed prime mover(VSPM) such as a wind turbine for the clean alternative renewable energy in rural areas. The basic steady-state characteristics of the VSPM are considered in the three-phase SEIG approximate electro-mechanical equivalent circuit and the operating performances of the three-phase SEIG coupled by a VSPM in the steady-state analysis are evaluated and discussed on line under the conditions related to the speed changes of the prime mover and the electrical inductive load power variations with simple computation processing procedures. A three-phase SEIG prototype setup with a VSPM is implemented for the small-scale clean renewable and alternative energy utilizations. The experimental performance results give good agreements with those ones obtained from the simulation results. Furthermore, a PI controlled feedback closed-loop voltage regulation of the three-phase SEIG driven by the VSPM on the basis of the static VAR compensator (SVC) composed of the thyristor phase controlled reactor (TCR) in parallel with the thyristor switched capacitor (TSC) and the fixed excitation capacitor bank (FC) is designed and considered for the wind generation as a renewable power conditioner. The simulation analysis and experimental results obtained from the three-phase SEIG with SVC for its voltage regulation prove the practical effectiveness of the additional SVC with the PI controller-based feedback loop in the steady-state operations in terms of the fast response and the high performances.

パワー半導体デバイスの実測データに基づく半導体電力変換装置の簡易電力損失分析シミュレータの開発

平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 122 ( 12 ) 1142 - 1143 2002年12月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper deals with a feasible power loss analysis simulator which can actually estimate the power losses of switching mode power converters using IGBTs. The power loss analysis simulator proposed newly is based upon the feasible measured switching power loss data tables and v-i characteristics data tables of power semiconductor power devices; IGBT and diodes. The effectiveness of practical simulation technique, which can discuss power loss evaluations for three phase PWM inverter, is confirmed from the viewpoints of the newly proposed simulation and experimental results.

DOI： 10.1541/ieejias.122.1142

共振ACリンク方式三相電圧形インバータの電磁ノイズ評価

吉田正伸, 平木英治, 中岡睦雄

電気学会研究会資料. EDD, 電子デバイス研究会 2002 ( 83 ) 13 - 18 2002年11月

アクティブ補助共振転流スナバインバータの新スイッチングシーケンスによるPWMパターン

中村萬太郎, 山崎貴幸, Ahmed Tarek, 平木英治, 中岡睦雄

電子情報通信学会技術研究報告. EE, 電子通信エネルギー技術 102 ( 475 ) 25 - 30 2002年10月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では無停電電源、商用連系分散型電源など各種のインバータ応用装置として、補助スイッチを持つアクティブ補助共振スナバを用いた部分共振ブリッジインバータを提案し、そのソフトスイッチングパルス変調方式並びに補助共振スナバ回路の最適設計条件について述べている。すなわち本インバータ方式は主スイッチの他に補助スイッチを含む部分共振スナバ回路が必要であるが、主スイッチおよび補助スイッチともにZVSまたはZCSによるソフトスイッチングを実現し、各スイッチのスイッチング損失の低減とインバータのノイズの低減が可能である。本回路の補助スイッチと共振スナバ回路は主スイッチがスイッチング動作する時点のみ働き、その最適設計をすることにより補助スイッチおよび共振スナバ回路の電流値を負荷電流値レベルに押さえることが可能である他、かつスイッチング時の電圧または電流の立上り立下り時間を設定することもできる。また本回路方式においてはソフトスイッチング動作を行うために特別の電圧または電流の検出回路をシステムの制御に持ち込む必要がない。この回路方式は直流電源の中点電位を必要としない。一般のソフトスイッチング技術と同様であるが、パワー半導体スイッチのスイッチング時間特性と導通時の飽和電圧降下特性にトレードオフの関係があるため、電圧降下特性の改善に特化したパワー半導体スイッチを適用すればさらに一層の効率向上が可能となることを言及している。

新方式高周波直列共振形ソフトスイッチングPFMチョッパ制御方式直流昇圧DC-DCコンバータ

〓恩輝, チャンタケートサラウット, 中村萬太郎, 平木英治, 中岡睦雄

電子情報通信学会論文誌. C, エレクトロニクス = The transactions of the Institute of Electronics, Information and Communication Engineers. C 85 ( 10 ) 917 - 924 2002年10月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では,まず,広い出力電圧制御設定域,入力電圧の変動域,負荷変動外乱に対して,安定なゼロ電流ソフトスイッチング(ZCS)動作ができる非絶縁回路トポロジーとなり得る新方式高周波直列共振形ZCS-PFMチョッパ制御直流昇圧DC-DCコンバータを提案している.次に本論文では,その定常回路動作と特徴を述べ,開ループ出力電圧制御特性を図説しかつ評価検討を行っている.更に,シミュレーション解析と試作実験により,本提案直流昇圧DC-DCコンバータの動作と性能評価を行い,その有効性を明らかにしている.

補助共振スイッチングブロックを用いた位相シフトZVS-PWM制御高周波負荷共振インバータとその応用

黒瀬洋一, 奥野敦, 平木英治, 中岡睦雄

電子情報通信学会技術研究報告. EE, 電子通信エネルギー技術 102 ( 338 ) 1 - 5 2002年9月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では新方式のソフトスイッチングPWM高周波インバータを提案し、その動作原理と特徴を述べ、電磁誘導流体加熱応用システムに適応しての性能評価を実験データを用いて行っている。

テクノロジー高効率・低電磁ノイズ高周波スイッチングPWM電力変換装置の開発

吉田正伸, 平木英治, 中岡睦雄

EMC 15 ( 4 ) 52 - 62 2002年8月

電圧形IGBTインバータ用一括インダクタ形共振ACリンクスナバの実証評価検討

吉田正伸, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 122 ( 6 ) 617 - 623 2002年6月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a new prototype configuration of a single-phase voltage source soft switching inverter using IGBT power module packages in order to reduce switching power losses, electromagnetic noises. A single inductor-assisted resonant AC link snubber circuit as one of the resonant snubbers to achieve the zero voltage soft switching for the single-phase voltage source inverter is originally demonstrated, and its operation principle and unique features as well as the practical parameter design method of resonant AC link snubber circuit treated here is described on the basis of computer-aided simulation analysis. Furthermore, the practical operating performans of the single inductor-type resonant AC link snubber for the single-phase voltage source soft switching inverter using IGBTs are discussed and evaluated on the basis of switching power losses and electromagnetic conductive noise as compared with those of single-phase voltage source hard switching inverter from an experimental point of view.

DOI： 10.1541/ieejias.122.617

X線管駆動用ゼロ電流ソフトスイッチングPFM高周波インバータ制御方式DC-DCコンバータ

〓恩輝, 石飛学, Moisseev Serguei, 平木英治, 中岡睦雄

電子情報通信学会論文誌. C, エレクトロニクス = The transactions of the Institute of Electronics, Information and Communication Engineers. C 85 ( 5 ) 356 - 366 2002年5月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

本論文では,小容量医用X線発生直流高電圧スイッチング電源の一方式としてパルス周波数変調(PFM)制御直列トランス共振インバータ駆動方式対称コッククロフト・ウォルトン形全波多倍圧整流回路から構成されるゼロ電流ソフトスイッチング高周波リンクDC-DCコンバータ電源システムを取り上げている.まず,本コンバータの開ループ系としての過渡応答特性と定常応答特性を広く外部設定される負荷抵抗(X線管等価抵抗値)パラメータとロスレスインダクタスナバを用いた高周波トランス直列共振インバータの共振回路パラメータや制御変数としてのインバータスイッチング周波数との関係で図示し,評価検討を行っている.次に本コンバータに対して高周波インバータの周波数切換制御アルゴリズム(デュアルモードPFM制御)を取り入れた管電圧フィードバック制御系に着ける過渡特性と定常特性を正規化パラメータや正規化変数を用いて定量的な評価検討を行っている.更に,本コンバータ出力電圧の過渡応答特性と定常応答特性を縮小モデル試作器による実験結果とシミュレーション結果のもとに本ゼロ電流ソフトスイッチング高周波PFMインバータ制御方式直流高電圧スイッチング電源の有効性を明らかにしている.

小容量X線管駆動用高周波直列共振形インバータ方式直流高電圧発生装置と性能評価

〓恩輝, 石飛学, 平木英治, 中岡睦雄

電気設備学会誌 22 ( 2 ) 134 - 143 2002年2月

ZVS&ZCS複合共振レッグリンクスナバを用いた三相電圧形インバータの検討〔含質疑応答〕

広田慶彦, 吉田正伸, 平木英治

パワーエレクトロニクス研究会論文誌 28 44 - 51 2002年

記述言語：日本語出版者・発行元：パワーエレクトロニクス研究会

In this paper, a novel type of active auxiliary quasi resonant commutation leg link Snubber for three phase soft switching inverter circuit, which can be completely turned on and turned off with ZVS & ZCS hybrid mode transition is presented and discussed. The operating principle of this auxiliary hybrid resonant commutation leg link (AHRCLL) snubber circuit is described, and its optimum circuit parameters are determined from a simulation point of view. In addition to these, the performances of this resonant snubber-assisted three phase voltage source type soft switching inverter are evaluated and discussed on the basis of simulation analysis.

DOI： 10.14913/jipe1995.28.44

An active auxiliary resonant AC link snubber with a single active power switch for voltage source type soft switching sinewave PWM inverter 査読

H Iyomori, M Yoshida, S Chandhaket, E Hiraki, M Nakaoka

2002 INTERNATIONAL CONFERENCE ON COMMUNICATIONS, CIRCUITS AND SYSTEMS AND WEST SINO EXPOSITION PROCEEDINGS, VOLS 1-4 1702 - 1706 2002年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents a novel active auxiliary resonant AC link snubber for soft switching sinewave PWM inverter. Its operating principle is described for current source load model during one sampling period and the circuit design method of this resonant snubber is pointed out by using the operating data. The performance evaluations of single phase zero voltage type soft switching pulse modulated inverter employing an active auxiliary resonant AC link snubber with a single power switch is illustrated as compared with those of a hard switching PWM sinewave inverter herein.

Space voltage vector modulated three phase inverter using auxiliary pulse current transformer-assisted resonant snubbers

C. Y. Inaba, S. Sato, S. Nagai, E. Hiraki, M. Nakaoka

Proceedings of the Power Conversion Conference-Osaka 2002, PCC-Osaka 2002 3 1200 - 1205 2002年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Institute of Electrical and Electronics Engineers Inc.

In this paper, a high frequency transformer-assisted auxiliary active resonant commutated snubber (HFTA-ARCS) for voltage source power conversion is presented. A three phase voltage source type soft switching inverter incorporating HFTA-ARCS circuits in its three bridge legs can reduce current rating of auxiliary active power switches and simplified sensorless control scheme without specified boost current management required for soft switching. Its operating principle and digital control scheme are described and a practical design procedure of circuit parameters on this HFTA-ARCS circuit is also introduced on the basis of computer simulation results. The effectiveness of this inverter is proved on the basis of performance evaluations and is also compared with the conventional three-phase hard switching inverter under the conditions of specified parameters.

DOI： 10.1109/PCC.2002.998143

Auxiliary active resonant commutated snubber-assisted 3-level 3-phase voltage source soft-switching inverter

M. Yamamoto, S. Sato, E. Hiraki, M. Nakaoka

Proceedings of the Power Conversion Conference-Osaka 2002, PCC-Osaka 2002 3 1245 - 1250 2002年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Institute of Electrical and Electronics Engineers Inc.

This paper presents a performance analysis in steady-state of a novel type auxiliary resonant commutation snubber-linked 3-level 3-phase voltage source type soft switching inverter suitable and acceptable for high-power applications in comparison with resonant DC linked 3-level 3-phase voltage source type soft switching inverter proposed previously which can operate under a condition of zero voltage switching (ZVS). The digital control scheme of this inverter is presented. The steady-state performances of this inverter are illustrated and evaluated on the basis of the simulation results.

DOI： 10.1109/PCC.2002.998151

アクティブ補助共振転流スナバ方式三相電圧形ソフトスイッチングインバータ

山元久明, 岩本英雄, 吉田正伸, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 121 ( 7 ) 823 - 824 2001年7月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a three phase voltage source space voltage vector modulated soft switching inverter using bridge leg-side active auxiliary resonant commutation snubbers (ARCS) with a high frequency pulse current transformer which is designed for power regeneration to DC source, along with its performance evaluations under a digital servo control scheme.

DOI： 10.1541/ieejias.121.823

MRI傾斜磁場発生用PWM電力増幅器の電流パターン追従ディジタル最適予見制御

渡辺修治, 高野博司, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 121 ( 7 ) 756 - 763 2001年7月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper deals with a two-paralleled switch-mode PWM power amplifier using current pattern tracking scheme in order to generate a gradient magnetic field in the Magnetic Resonance Imaging (MRI) system. This power conversion circuit has 8-IGBTs at their inputs/outputs so as to realize further high-power density, and to reduce current switching ripple of the Gradient Coils (GCs) as well as to raise current responses. The modern optimal preview control implementation in 2 parallel bridge type PWM power amplifier can improve the quick and precise current pattern tracking control responses in accordance with the specified values for the magnetic field in GCs. It is clearly proven from a theoretical point of view that the proposed control software is to be enlarged highly the diagnostic target and improves the image quality of MRI systems.

DOI： 10.1541/ieejias.121.756

3レベル三相電圧形ソフトスイッチングインバータの実証的評価

山本真義, 平木英治, 中岡睦雄

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 121 ( 7 ) 821 - 822 2001年7月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a novel type of 3-level 3-phase voltage-fed soft switching inverter with two new Auxiliary Resonant DC Link (ARDCL) snubbers topologies which can operate under a condition of Zero Voltage Switching (ZVS). The feasible operating performances of the proposed soft switching inverter using IGBT module which is more suitable for power systems applications is evaluated on the basis of its experimental results.

DOI： 10.1541/ieejias.121.821

パルス電流トランス付アクティブ補助共振転流スナバと最適回路設計

山元久明, 平木英治, 奥野敦, 中岡睦男

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 121 ( 4 ) 522 - 523 2001年4月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents a novel prototype of auxiliary resonant commutated snubber (ARCS) which incorporates a high frequency pulse current transformer with power regeneration diode loop, along with its practical design considerations.

DOI： 10.1541/ieejias.121.522

高周波パルス電流トランスを用いた三相電圧形ソフトスイッチングインバータとその実証評価

山元久明, 平木英治, 中村万太郎, 中岡睦雄

電気学会半導体電力変換研究会資料 SPC-01 ( 26-37 ) 2001年

Auxiliary resonant commutated snubber linked 3-level 3-phase voltage source soft-switching inverter

M. Yamamoto, E. Hiraki, Y. Konishi, M. Nakaoka

Conference Record - IAS Annual Meeting (IEEE Industry Applications Society) 3 1455 - 1460 2001年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents a performance analysis in steady-state of a novel type Auxiliary Resonant Commutation Snubber-linked 3-level 3-phase voltage source type soft switching inverter suitable and acceptable for high-power applications in comparison with resonant DC linked 3-level 3-phase voltage source type soft switching inverter proposed previously which can operate under a condition of Zero Voltage Switching (ZVS). The digital control scheme of this inverter is presented. The steady-state performances of this inverter are illustrated and evaluated on the basis of the simulation results.

Practical design procedure of resonant snubber with current transformer and performance evaluations of a digitally controlled three phase soft switching inverter

C. Y. Inaba, Y. Hirota, Y. Konishi, E. Hiraki, M. Nakaoka

Conference Record - IAS Annual Meeting (IEEE Industry Applications Society) 4 2448 - 2454 2001年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, a high frequency transformer-assisted auxiliary active resonant commutation snubber (HFTA-ARCS) for voltage source soft switching pulse width modulated power conversion and inversion circuits using IGBTs is presented. A three phase voltage source type soft switching inverter incorporating HFTA-ARCS circuits in its three bridge legs can reduce current rating of auxiliary active power switches and has sensorless simplified control scheme which any specified boost current management is not required for soft switching. Its operation principle and digital control scheme are described and a practical design method of circuit parameters on this HFTA-ARCS circuits is also introduced on the basis of computer simulation. Moreover, this space vector modulated soft switching inverter system with DSP-based digital control scheme is discussed on the basis of performance evaluations. The effectiveness of this inverter is proved by simulation results. The operating performances of this inverter system are compared with those of conventional three-phase hard switching inverter under practical conditions of specified parameters.

高周波ソフトスイッチングインバータを用いた電磁誘導流体加熱装置

金田充, 平木英治, 中岡睦雄, 弘田泉生, 大森英樹

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 120 ( 8 ) 1088 - 1089 2000年8月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents an electromagnetic induction eddy current-based continuous fluid heating appliance using voltage-fed quasi resonant high-frequency soft switching inverter with time ratio control scheme. Its power regulation characteristic are illustrated and this new consumer appliance is evaluated on the basis of its computer simulation and 4kW experimental setup.

DOI： 10.1541/ieejias.120.1088

部分共振ZVS-PWM制御高周波インバータの近似電力算定式

金田充, 平木英治, 中岡睦雄, 弘田泉生, 大森英樹

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 120 ( 8 ) 1086 - 1087 2000年8月

記述言語：日本語出版者・発行元：一般社団法人電気学会

This paper presents an approximate equation to evaluate the regulated output power of asymmetrical ZVS-PWM high frequency quasi resonant inverter for induction heating. Its approximate output power regulation characteristics derived from a theoretical point of view are discussed for induction heating loads as compared with the simulation results.

DOI： 10.1541/ieejias.120.1086

3-Level 3-phase voltage-fed soft-switching inverter with new space voltage vector modulation scheme for dispersed new energy power supply and its feasible evaluations

M. Yamamoto, E. Hiraki, M. Ando, M. Nakaoka

2000 IEEE Power Engineering Society, Conference Proceedings 4 2465 - 2470 2000年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Institute of Electrical and Electronics Engineers Inc.

This paper presents a digitally-controlled three-level three-phase voltage source soft switching inverter with two auxiliary resonant DC link (ARDCL) snubbers which can operate under the condition of zero voltage switching (ZVS). Its operating principle and its related new instantaneous space vector allocation method are proposed and discussed. The feasible performances of this soft switching inverter, suitable for high power applications, are illustrated and evaluated as compared on the basis of simulation and experimental results with a three-level three-phase hard switching inverter.

DOI： 10.1109/PESW.2000.847196

Simulation method for DSP-controlled active PFC high-frequency power converters

S. Mobin, E. Hiraki, H. Takano, M. Nakaoka

IEE Proceedings: Electric Power Applications 147 ( 3 ) 159 - 166 2000年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEE

A generic simulation approach for digital-signal-processor (DSP) controlled power converter systems is described. Software program statements for simulating a feedback control scheme could also be incorporated in the software code of a DSP-controlled power conversion system. The power electronic circuit simulation technique is based on the substitution of switch-modulated resistors in place of all the active and/or passive power switches
one state equation described by state variables, i.e. inductor currents and capacitor voltages, and the solution of the state equation is computed by an appropriate numerical method. The simulation approach is explained by a practical application example of the DSP-controlled active-switch three-phase power-factor-correction (PFC) converter system.

DOI： 10.1049/ip-epa:20000375

3-Level 3-phase voltage-fed soft-switching inverter with new space voltage vector modulation scheme and its feasible evaluations

M. Yamamoto, H. Iwamoto, E. Hiraki, T. Horiuchi, Y. Sugawara, M. Nakaoka

IEE Conference Publication ( 475 ) 541 - 547 2000年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEE

This paper presents of digitally-controlled 3-level 3-phase voltage source type soft switching IGBT inverter topology with two Auxiliary Active Resonant DC Link (ARDCL) snubbers which can operate under a condition of Zero Voltage Switching (ZVS). Its operating principle and its related new instantaneous space vector allocation modulation method are proposed and discussed for telecommunication energy plants. The feasible performances of ARDCL-assisted soft switching inverter suitable for high power applications is illustrated and evaluated on the basis of simulation and experimental results as compared with the 3-level 3-phase hard switching inverter using IGBT power modules.

DOI： 10.1049/cp:20000305

Multifunctional digitally-controlled bidirectional three-phase soft-switching PWM converter

Hisaaki Yamamoto, Claudio Yudi Inaba, Eiji Hiraki, Mutsuo Nakaoka

IEE Conference Publication ( 475 ) 86 - 90 2000年

掲載種別：研究論文（学術雑誌）

In this paper, a prototype of a multifunctional controlled three-phase voltage-source bidirectional zero voltage soft- switching PWM converter with three auxiliary active resonant commutated snubber link (ARCSL) is presented for Battery and/or Electric Double Layer Capacitor Energy Storage System (BESS) and Active Power Filter System (APFS). The operating principle of this active resonant snubber-assisted soft-switching converter circuit and multi-functional digital control-based converter system including active rectifier and inverter operation modes are described herein. The effectiveness of Soft-Switching Bidirectional converter system is proved on the basis of simulation analysis.

DOI： 10.1049/cp:20000225

Feasible performance evaluations of 3-level 3-phase voltage source soft-switching inverter using IGBT modules

M. Yamamoto, M. Yoshida, T. Honda, H. Iwamoto, E. Hiraki, S. Sugimoto, I. Kouno, M. Nakaoka

Proceedings of the International Conference on Power Electronics and Drive Systems 2 1084 - 1089 1999年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents feasible performance of digitally-controlled 3-level 3-phase voltage source type soft switching inverter with two Auxiliary Resonant DC link snubbers which can operate under a condition of Zero Voltage Switching (ZVS). The operating principle of this inverter topology suitable for high power energy storage utilization system is discussed as compared with 2-level soft switching inverter. The system effectiveness of new inverter treated here are proved on the basis of the experimental results.

DOI： 10.1109/peds.1999.792859

Performance evaluations of three-phase voltage source instantaneous voltage vector modulated soft commutation inverter with active resonant snubbers in three-phase AC load side

Masanobu Yoshida, Kouki Ogura, Hideo Iwamoto, Eiji Hiraki, Mutsuo Nakaoka

IECON Proceedings (Industrial Electronics Conference) 2 903 - 908 1999年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper describes a three-phase voltage source-fed soft switching inverter system with auxiliary resonant AC link snubbers for CVCF application which incorporates by the optimal type-1 servo controller operated on the d-q coordinate frame. In this paper, the steady state and transient-state operating performance tills soft switching inverter and is illustrated and evaluated on the basis of its computer simulation analysis. The circuit design procedure of active resonant snubber circuit topology in AC side is illustrated by the simulation results. The effectiveness of this soft switching inverter is proved from a practical point of view.

Three-phase voltage source NPC soft-switching inverter for interactive energy storage plants

M. Yamamoto, M. Yoshida, H. Iwamoto, E. Hiraki, S. Sugimoto, I. Kouda, M. Nakaoka

INTELEC, International Telecommunications Energy Conference (Proceedings) 29 - 21 1999年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents feasible performance of digitally-controlled three-level three-phase voltage source soft switching inverter with two Auxiliary Resonant DC link snubbers which can operate under a condition of Zero Voltage Switching (ZVS). The operating principle of this inverter topology is suitable for high power energy storage utilization system is discussed as compared with two-level soft switching inverter. The system effectiveness of new inverter treated here are proved on the basis of the experimental results.

Voltage-fed NPC soft-switching inverter with new space voltage vector modulation scheme

M. Yamamoto, E. Hiraki, H. Iwamoto, S. Sugimoto, I. Kouda, M. Nakaoka

Conference Record - IAS Annual Meeting (IEEE Industry Applications Society) 2 1178 - 1185 1999年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper presents of digitally-controlled 3-level 3-phase voltage-fed soft switching inverter with two Auxiliary Resonant DC Link (ARDCL) snubbers which can operate under a condition of Zero Voltage Switching (ZVS). Its operating principle and its related new instantaneous space vector allocation method are proposed and discussed. The feasible performances of this soft switching inverter treated here which are suitable for high power utilization systems is illustrated and evaluated as compared with the 3-level 3-phase hard switching inverter on the basis of simulation and experimental results.

Novel soft-switching dc-dc power converter with high-frequency transformer secondary-side phase shifted PWM active rectifier

Takeshi Morimoto, Shinya Shirakawa, Eiji Hiraki, Mutsuo Nakaoka

INTELEC, International Telecommunications Energy Conference (Proceedings) 5 - 3 1999年

掲載種別：研究論文（国際会議プロシーディングス）

This paper presents a novel prototype of soft-switching PWM DC-DC power converter using synchronous active power switches in series with each rectifier diode in high-frequency transformer secondary side. This high-efficient soft-switching DC-DC power converter topology with transformer link that is suitable for high-power applications can completely achieve soft-switching under the condition of no freewheeling current operation and wide load variations. Using the proposed soft-switching PWM DC-DC power converter, switching losses of active power devices and their conduction losses are both reduced as compared with the previously-developed soft-switching PWM DC-DC converter. The steady-state operating characteristics of the proposed power converter circuit and its unique features are illustrated and discussed on the basis of the simulation analysis and some results of 2kW-40kHz experimentation.

Utility-interactive three-phase soft-switching pulse width modulated converter with active resonant snubbers in bridge leg sides for energy storage devices

Hisaaki Yamamoto, Eiji Hiraki, Yoshihiro Konishi, Katsumi Nishida, Toshikazu Horiuchi, Yoshitaka Sugawara, Mutsuo Nakaoka

IECON Proceedings (Industrial Electronics Conference) 2 897 - 902 1999年

掲載種別：研究論文（国際会議プロシーディングス）

In this paper, a prototype of a multi-functional controlled three-phase voltage-source bidirectional zero voltage soft-switching PWM converter with three auxiliary active resonant commutated snubber link (ARCS) is presented for Battery and/or Electric Double Layer Capacitor Energy Storage System (BESS). The operating principle of this active resonant snubber-assisted soft-switching converter circuit for BESS and multi-functional digital control-based converter system including active rectifier and inverter operation modes are described herein. The operation characteristics of this bidirectional three phase soft-switching space voltage vector modulated converter with ARCS for BESS is demonstrated under the conditions of battery charging-based peak-cut mode and battery charging-based energy storage mode in comparison with conventional utility-connected three phase hard-switching converter for BESS. The effectiveness of the converter system is proved on the basis of simulation analysis.

Digitally-controlled three phase soft-switching PFC converter with instantaneous power feedback control scheme

M. Yamamoto, H. Hattori, E. Hiraki, M. Nakaoka

PEDES 1998 - 1998 International Conference on Power Electronic Drives and Energy Systems for Industrial Growth 2 1002 - 1006 1998年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Institute of Electrical and Electronics Engineers Inc.

This paper presents a performance analysis in steady-state and transient-state of auxiliary resonant commutation snubber (ARCS)-linked three phase voltage source soft switching PFC rectifier with a digital control scheme which is suitable for high power applications as compared with three phase hard switching PFC rectifier. The system performances of this soft-switching PFC rectifier are illustrated and evaluated on the basis of the experimental results.

DOI： 10.1109/PEDES.1998.1330738

Object-oriented simulation of DSP controlled three phase active PFC converter

S. M. Ulhaq, E. Hiraki, M. Nakaoka, H. Takano

IEE Conference Publication ( 456 ) 28 - 33 1998年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEE

In this paper, an efficient power electronic circuit simulation approach is discussed for a digitally controlled three phase active PFC converter system. The control circuit simulation software used in this simulation technique is also applied to the digital signal processor (DSP) based control implementation of a practical power factor correction (PFC) power conversion circuit with a digital control scheme. This circuit simulation technique is based on a circuit equation modeled by substituting control input dependent time-varying resistors in place of all the power switches incorporated in the bridge arms of the three phase active PFC converter circuit and system treated here, one state-vector equation described by state-variables for inductors and capacitors, together with an algebraic computation method to transform the matrix of the circuit equation into matrix of the state vector equation. In addition, this paper proves the effectiveness of a voltage-fed three phase PFC converter with a digital control PWM strategy and its performance evaluations on the basis of computer-aided simulation results together with experimental results.

DOI： 10.1049/cp:19980495

Three phase voltage-fed space vector modulated soft-switching PFC rectifier with instantaneous power feedback scheme

M. Yamamoto, S. Hattori, E. Hiraki, M. Nakaoka, T. Horiuchi, Y. Sugawara

IEE Conference Publication ( 456 ) 92 - 98 1998年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEE

This paper presents performance evaluations in steady and transient-states of quasi-resonant commutated bridge arm link three phase PFC rectifier with instantaneous power feedback and DC output voltage regulation loops. This three phase PFC rectifier topology is based upon digitally-modulated sinewave space vector processing, which can operate under a principle of ZVS-PWM transition due to auxiliary quasi-resonant commutation circuit incorporated into each three phase bridge arm. In the first place, a practical design of auxiliary resonant commutation circuit with current source type load model is graphically described on the basis of its state variable analysis. In the second place, the digital control system of three phase voltage-fed soft-switched PWM converter suitable and acceptable for high power utility applications is implemented on the synchronous rotating d-q coordinate axis. Finally, a novel prototype of this three phase PFC rectifier operating at soft-switching PWM strategy is evaluated as compared with hard switching PWM three phase PFC rectifier in terms of computer-aided simulation results.

DOI： 10.1049/cp:19980506

IV. 共振形電力変換器の応用

中岡睦雄, 平木英治

電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society 117 ( 2 ) 129 - 132 1997年2月

高周波共振形電力変換関連技術共振形電力変換器の応用

中岡睦雄, 平木英治

電気学会論文誌 D 117 ( 2 ) 1997年

最近のスイッチング技術

中岡睦雄, 平木英治

電気学会論文誌 D 1997 ( 4 ) 1997年

New phase-shifted soft-switching PWM series resonant inverter topologies and their practical evaluations

Satoshi Nagai, Eiji Hiraki, Yasuhiro Arai, Mutsuo Nakaoka

Proceedings of the International Conference on Power Electronics and Drive Systems 1 318 - 322 1997年

掲載種別：研究論文（国際会議プロシーディングス）

This paper presented three versions of phase-shifted soft-switching PWM with constant frequency or load-adaptive PFM series resonant inverter topologies. Constant frequency phase-shifted inverter is widely used for high power applications. But soft-switching operation is not realized, operating frequency range is limited to around 20 kHz. To introduce load-adaptive PFM control, lossless capacitors, lossless inductors, switching losses and stresses are much reduced and frequency limit is extended more than 100 kHz for IGBTs for example. These inverters are suit for induction-heating applications in metal electroheat processing plants, food cooking processing plants, hot water and hot gas producing processing plants.

太陽電池から所望の駆動力を得るための誘導機システムの制御

泉照之, 田村敬造, 平木英治, 中岡睦雄

パワーエレクトロニクス研究会論文誌 21 ( 1 ) 91 - 100 1995年

出版者・発行元：パワーエレクトロニクス学会

Solar energy is more attractive and acceptable as one of available power sources in future from a view point of a clean and inexhaustible power supply. However, the electric power generated from a solar photovoltaic array largely depends on weather conditions. Therefore a constant mechanical power can not be obtained from one motor which is driven on the basis of the electric power from a solar photovoltaic array. In order to produce a stable mechanical power, the authors propose the parallel operation system using two induction machines.<br>This paper presents on the stability of the proposed system in which the machine A is related to a solar phtovoltaic array coupled with a general purpose inverter and another machine B is interconnected directly to the utility-grid AC line. It is shown that the system can generate a stable mechanical power with cooperation of the machine B even if the output power of the machine A becomes zero. Furthermore the operating frequency of the inverter is determined by utilizing the relation of the maximum power and the optimal operating voltage of a solar photovoltaic array. As a result, the output power of the machine A becomes always a maximum value under variable weather conditions.

DOI： 10.14913/jipe1995.21.91

Optimal control of a servo system regenerating conservative energy to a condenser

Teruyuki Izumi, Prasanna Boyagoda, Mutsuo Nakaoka, Eiji Hiraki

International IEEE/IAS Conference on Industrial Automation and Control: Emerging Technologies, Proceedings 651 - 656 1995年

掲載種別：研究論文（国際会議プロシーディングス）

An Optimal controller for a servo system with a manipulator is developed. The emphasis is on the minimization of the overall energy consumption of the system. The optimum current function is obtained under the minimization criteria of the consumption energy for a manipulator under gravity conditions and otherwise. The solution to the two-point-boundary-value-problem is obtained by using the Generalized Newton-Raphson method. Further when the link of the manipulator is decelerated, the generated electric power from the motor is stored in a condenser. This is achieved while supplying the optimal current by using a DC Chopper circuit. It is shown from experiment that the efficiency of energy storage is improved by increasing the capacitance of the condensers. The overall energy is shown to decrease by this method.

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