Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2023.3252490

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2023.3248519

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2023.3247685

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

We have been investigating the possibility of a low-frequency and high-efficiency wireless power transmission (WPT) system for the railway vehicle using a high-temperature superconducting (HTS) coil. We investigated a basic HTS coil structure having a low ac loss and a high coupling coefficient between the primary and secondary coils by adjusting a radial gap between turns. The devised HTS coil was configured to have a radial gap approximately equal to the HTS tape width and increase the number of turns while reducing the inner diameter of the coil. Also, we analyzed the power transmission characteristics in the 40 kW class WPT system using the devised HTS coils operated at a low frequency around 1 kHz for the railway vehicle. Furthermore, we fabricated the 1 kW class WPT model system at an operating frequency of 0.92 kHz using the devised HTS coil and demonstrated the effectiveness of the low-frequency and high-efficiency WPT system using the devised HTS coil structure. As a result, we clarified that the low-frequency WPT system using the devised HTS coil for the railway vehicle can perform more rapid charging and the high-efficiency transmission than that using the copper coils.

DOI： 10.1109/tasc.2022.3220342

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

In this paper, we discuss two points: (a) the accuracy of contact resistance measurement using the low-frequency AC (LFAC) method and (b) the relation between the contact resistance and the contact resistivity. The LFAC method is used to measure the turn-to-turn contact resistance of a no-insulation (NI) rare-earth barium copper oxide (REBCO) pancake coil. We have previously shown the validity of the LFAC method by experiment. In this paper, the current distribution of aNI REBCO pancake coil on the applyication of the LFAC method is investigated using numerical simulation. The simulation results show the possibility of improving the measurement accuracy. Hence, a correction method is also proposed using the phase difference of the coil voltage and current. The LFAC simulation results also indicate the inconsistency of the well-known relation between contact resistance and contact resistivity. Therefore, we investigated the relation through the LFAC and sudden-discharging test simulations.

DOI： 10.1088/1361-6668/aca5b9

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2023.3258911

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2023.3259923

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

In recent years, an ultrafine Nb3Al wires with a diameter of less than 50 mu m has been developed by a research group at the National Institute for Materials Science (NIMS) in Japan. Therefore, we are planning to use the developed high performance Nb3Al wires for superconducting applications operated by cryocooler. In order to design the superconducting applications cooled by cryocooler, it is necessary to measure the temperature and magnetic field dependence of the critical current of Nb3Al wires under conduction cooling conditions. Single and seven-stranded Nb3Al wires with different diameters (phi 67 mu m and phi 81 mu m) fabricated by the Jelly-rolled method were prepared. The barrier material of the two samples is the same Nb, but the core materials are Nb (phi 67 mu m) and Ta (phi 81 mu m), respectively. The Cu/nonCu ratio of the two samples is 1. In this study, the critical currents of sample wires were measured by a four-probe method with current sweep and constant current, and they were compared to define a reasonable critical current value under conduction cooling. Under conduction cooling, it was confirmed that the critical current measurement by the constant current method was more accurate than the current sweep method.

DOI： 10.1109/tasc.2022.3156927

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

We have proposed a cyclotron for cancer therapy, called Skeleton Cyclotron, which is based on non-insulation (NI) high temperature superconducting (HTS) technology. The Skeleton Cyclotron consists of circular main coils for the isochronous field and non-circular sector coils for the azimuthally varying field (AVF). In order to establish the development technology of HTS multi-coil system for the skeleton cyclotron, we have now designed a small half-size multi-coil system for demonstration, called Ultra-Baby Cyclotron, at the operating current of 540 A, the operating temperature of 20 K and the magnetic field of 1.6 T at the extraction radius of 0.2 m. The NI HTS coil can make both high current density and high magnetic field, so it can achieve miniaturization of its size and high intensity beams. Furthermore, in NI coils, the current flows not only in the coil winding direction but also in the radial direction. Therefore, even if the local normal transition occurs in the coil windings, the current can bypass into the neighboring wires and thermal stability can be improved. On the other hand, when the normal transition and quench occur, the electromagnetic and mechanical behaviors in NI coils are different from those of conventional insulated coil. Therefore, we developed a current distribution analysis code for non-insulation HTS coils and simulated the current distributions during the normal transition and quench in NI REBCO coil system for Skeleton Cyclotron.

DOI： 10.1109/tasc.2022.3174811

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

In recent year, there has been remarkable progress in the use of high-field rare-earth barium copper oxide (REBCO) coils in NMR, MRI, and accelerator applications. No-insulation (NI) winding techniques are adopted to achieve high thermal stability and high current density. Thus, each winding in a non-impregnated NI REBCO coil can deform separately and move freely because of the thermal strain and electromagnetic force. The additional force and stress due to a screening current has also become an issue in REBCO coils. The screening current leads to a non-uniform force distribution in REBCO tapes and forces exceeding an acceptable value. It has been reported that REBCO coils have experienced mechanical deterioration or damage when operating under high magnetic fields. However, the detailed mechanism for this damage or deterioration has not been clarified. In order to clarify the detailed mechanism of this damage to a REBCO coil, the stress and strain during the winding, cooling down, charging, and discharging processes need to be evaluated. Furthermore, in NI REBCO coils, the turn-to-turn contact configurations are very important for the current bypassing, the thermal and mechanical stability. In previous studies, we have developed the numerical simulation code on the electromagnetic behavior of screening current and mechanical behavior of the turn-to-turn contact state. This study numerically evaluated the deformation and stress in REBCO tape and the turn-to-turn contact in NI REBCO coils.

DOI： 10.1109/tasc.2022.3171160

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

In recent years, high field REBCO coils have been applied with great interest to NMR and accelerators due to their high thermal stability and high current density. However, deteriorations and damages of REBCO coils are occurring. During the charge and discharge of REBCO coils, screening currents are induced to circulate in the windings, resulting in a non-uniform current distribution in the wires. It has been reported that the electromagnetic force distribution in the wire becomes significantly non-uniform, resulting in degradation of REBCO coils. In this study, the effects of stress and deformation of REBCO coils were investigated through electromagnetic stress analysis using two-dimensional axisymmetric structural analyses, taking into account thermal stress during cooling, tension during winding and electromagnetic force during not only charge and but also discharge, and the suppression of stress and deformation by the currently devised YOROI-coil (Y-based oxide superconductor and reinforcing outer integrated coil) structure and over-banding was evaluated.

DOI： 10.1109/tasc.2022.3177389

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

We are developing a high-temperature superconducting (HTS) air-core compact cyclotron, named Skeleton Cyclotron (Ueda et al. 2013), (Ueda et al. 2019), that can accelerate various particles and variable energy for radioisotope (RI) production. The coil system of Skeleton Cyclotron consists of circular main coils and noncircular sector coils which are wound by REBa2Cu3O6+delta (REBCO) tape applied no-insulation (NI) winding technique for both high current densities and thermal stabilities. The electromagnetic and thermal behaviors in NI coil differs from those in conventional insulated coils during charging, discharging, and quenching. Therefore, it is necessary to investigate the mechanical behavior and reinforcement structure of multiple NI coils in Skeleton Cyclotron. In this study, we report on the numerical evaluation of mechanical properties of NI REBCO coils in Skeleton Cyclotron at charging and quenching considering the current distributions and electromagnetic stresses unique to NI coils. In the quenching process, the radial current in a quenching pancake of the sector coil became dominant, resulting in generating the rotating force and non-symmetric deformation. YOROI-coil (Y-based oxide superconductor and reinforcing outer integrated coil) structure is effective for the additional magnetic stress.

DOI： 10.1109/tasc.2022.3163693

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

No-insulation (NI) winding technique provides high thermal stability, and the turn-to-turn contact resistance is an important factor to characterize the thermal stability and charging delay of NI HTS magnets. Therefore, a method that can accurately measure the contact resistance between turns of NI HTS magnets was required. We have previously proposed a turn-to-turn contact resistance measurement method using a low frequency AC current. The proposed low-frequency-AC-current (LFAC) can accurately evaluate the contact resistance between turns only when the whole AC current flows in the radial direction of the NI HTS pancake coil (there is almost no coil inductance). In addition, the AC current flowing in the radial direction needs to have a uniform current distribution in the plane of winding wire (REBCO wire). Therefore, in this study, an experimental study was conducted to prove the reliability of the proposed LFAC method. In the experiment, three NI test coils with different winding tension (0.5, 1 and 2 kg) were prepared, and four pickup coils were placed under each test coil to evaluate the radial current bypass characteristics. The contact resistance of each test coil was decreased from a few percent to several tens of percent by multiple cooling cycles from room temperature to liquid nitrogen temperature. Although it is a qualitative observation, the validity of the LFAC method was proved by the prepared pickup coils, and it was shown that even a small change of contact resistance in NI coils can be measured.

DOI： 10.1109/tasc.2022.3175791

Web of Science

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

We devised an HTS cable termination applying a wireless power transmission (WPT) system. The WPT system for the HTS cable termination can mechanically separate the HTS cable (low temperature part) from the copper cable (normal temperature part). In order to clarify the feasibility and design guidelines of the WPT system for the HTS cable termination, it is necessary to investigate the power transmission characteristics of the WPT system using the HTS and copper coils. In this study, we analyzed the power transmission characteristics of the simple WPT model system for the HTS cable termination by an equivalent circuit model and a finite element method analysis, and investigated the basic coil structure for the HTS cable termination applying the WPT system. As a result, the high-efficiency WPT system for the HTS cable termination can be realized by increasing the transport current of the HTS coil more than that of the copper coil. Also, we found that the HTS-Cu system using the primary-side HTS coil and the secondary-side copper coil is suitable for the HTS cable termination applying the WPT system.

DOI： 10.1109/tasc.2022.3167933

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

In recent years, a development of a high magnetic field magnet using a high temperature superconducting (HTS) wire has been advanced. On the other hand, we are planning to use the HTS wires for superconducting applications cooled by cryocooler. So, it is necessary to measure the temperature dependence of the magnetic properties of the metal substrates (Hastelloy, stainless steel and NiW) for HTS wire under conduction cooling conditions. We have been developing a single sheet tester (SST) that can evaluate the magnetic properties of electromagnetic steel sheets and other materials. However, since the size of an excitation coil in the conventional SST is large, it is difficult to install them in the conduction cooling system. In this study, we fabricated the compact SST and its measurement accuracy was compared with the conventional SST. The magnetic properties of metal substrates were measured at room temperature and liquid nitrogen temperature (77 K). As a result, although the measurement accuracy of the compact SST was slightly reduced by decreasing the coil size, we found that the error of the magnetic field homogeneity of the compact SST was within 2% at the center region of the 5 mm length. The magnetic properties of Hastelloy and stainless steel were almost unchanged at both room temperature and liquid nitrogen temperature. However, the magnetic properties of the NiW substrate changed significantly at liquid nitrogen temperature. The B-H characteristics of the NiW substrate in the rolling and transverse directions were clearly different, and the iron loss increased significantly at liquid nitrogen temperature.

DOI： 10.1109/tasc.2022.3159499

Web of Science

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

We have been investigating a wireless power transmission (WPT) system using a high-temperature superconducting (HTS) coil for a railway vehicle. In the previous research, we investigated the conceptual design of the WPT system using the HTS coils for the railway vehicle. However, in order to suppress the AC loss per HTS coil below the cooling power of a cryocooler, it was necessary to install multiple HTS coils in parallel on the vehicle and ground sides. Therefore, we investigated the low-loss and high-energy density coil structure in the WPT system for the railway vehicle. In this study, we analyzed the AC loss and the coupling coefficient of various HTS coil structures using the narrow REBaCuO (RE: Rare Earth elements, REBCO) wires in parallel by finite element method (FEM) calculation, and evaluated the power transmission characteristics of the WPT system using the HTS coil structures using the narrow REBCO wires in parallel for the railway vehicle. As a result, we found that the AC loss of the HTS coil structure using the narrow REBCO wires in parallel was lower than that using the wide REBCO wire. The coupling coefficient between coils using a single pancake coil structure was higher than that using a double pancake coil structure. Also, the receiving power density of the WPT system was improved by the HTS coil structures using the narrow REBCO wires. Particularly, the receiving power density of the single pancake coil using the twisted narrow wire in parallel in the coil radial direction increased to about 1.5 times that of the single pancake coil using the wide wire.

DOI： 10.1109/tasc.2022.3169997

Web of Science

researchmap

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

A wireless power transmission (WPT) system using the high temperature superconducting (HTS) coil for a railway vehicle is required to transmit the electric power of several hundred kW in a short time (60 s). In order to design the WPT system using HTS coil with the thermal stability, and it is necessary to clarify the thermal characteristics of the HTS coil at the operating current in kHz band and the operating conditions considering thermal stability in the WPT system. We analyzed the frequency characteristics of the critical current in the HTS coil above 1 kHz and investigated the operating conditions considering thermal stability in the WPT system for the railway vehicle using HTS coil in liquid nitrogen. As a result, the critical current of the HTS coil in the kHz band decreased with the frequency. This is because the AC loss in the HTS coil increased with the frequency, and the critical current density of the HTS coil decreased with increasing the surface temperature. In order to design the HTS coil with thermal stability in the kHz band, and it is necessary to operate the HTS coil on alternating current less than about 50% of the critical current measured by direct current. We found that the thermally stable WPT system capable of fast charging for 60 seconds can be realized by operating current at the frequency of about 2 kHz.

DOI： 10.1109/tasc.2021.3059234

Scopus

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

To achieve high-field rare-earth barium copper oxide (REBCO) coils, the mechanism of the deterioration of or damage to such coils needs to be clarified. A REBCO coil experiences various stresses and strains during the winding, cooling down, charging, and discharging processes. Furthermore, the additional force and stress due to a screening current has become an issue in REBCO coils. To protect REBCO coils from large electromagnetic stress in a high field, a reinforcement structure called the Y-based oxide superconductor and reinforcing outer integrated (YOROI) coil was proposed. This study numerically evaluated the effect of the YOROI coil structures against thermal and electromagnetic stress using a two-dimensional axisymmetric structural analysis. This simulation considered the following: 1) the mechanical stress induced by 10 N of winding tension, 2) thermal stress during cooling from 300 K to 10 K, and 3) electromagnetic stress, which included the additional stress due to a screening current during the charging process. The mechanical behavior due to each process was investigated, and the effect of the YOROI structures was also examined.

DOI： 10.1109/tasc.2021.3060702

Scopus

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

The characteristics of no-insulation high-temperature superconducting (HTS) manet is dominated by the magnitude of the turn-to-turn contact resistance. A few techniques have been proposed to increase the turn-to-turn contact resistance. The relation between the turn-to-turn contact resistance and the magnet stability has also been investigated in simulations. Although the turn-to-turn contact resistance measurement was only the sudden-discharging method before, we proposed a low-frequency-AC current (LFAC) method. Using our proposed method, it is possible to measure the turn-to-turn contact resistance under various conditions. In a previous paper, we measured it when charging DC current to a single pancake coil. In this paper, the turn-to-turn contact resistance was measured by the LFAC method when an external field of 1-3 T was applied to a single pancake coil. The coil strain was also measured, and the relation of the turn-to-turn contact resistance and the coil strain was also discussed.

DOI： 10.1109/tasc.2021.3070232

Scopus

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2021.3072871

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tasc.2021.3063654

researchmap

Authorship：Lead author   Language：Japanese  

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

© 2002-2011 IEEE. In this paper, we investigated a large-capacity Wireless Power Transmission (WPT) system operating in the kHz frequency band using high-temperature superconducting (HTS) coils for a railway vehicle. We analyzed the ac losses of the HTS coils using finite element method (FEM) and obtained the transmission efficiency at the power transmission of 38.7 kW at 0.8 and 4.3 kHz. As a result, we clarified that the transmission efficiency between the primary HTS coil and the secondary HTS coil of the WPT system for the railway vehicle is more than 90%. The heat generation in the coils can be suppressed by using the HTS coils for the WPT system. The ac losses per cycle (J/cycle) increased as operating frequency decreased since the HTS tape length increased with the lower operating frequency to achieve the same power transmission. However, the total loss per unit time (W) of the HTS coils did not nearly increase with the frequency. This result suggests that the WPT system using the HTS coil can be operated at the low-frequency region around 1 kHz. The system efficiency including the cryocooler power loss was lower than the transmission efficiency using copper coils. However, the analysis result shows that, if the critical current density of a commercial HTS tape at 77 K increases by approximately four times, the WPT system with HTS coils can realize a higher-efficiency and longer-time operation in a low frequency region of kHz than the system with the copper coils.

DOI： 10.1109/TASC.2019.2904649

Scopus

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

We have investigated the application of a high-temperature superconducting (HTS) coil to a high-power wireless power transmission system operated in the frequency region less than 10 kHz. In order to reduce the ac loss of the HTS coil, it is necessary to clarify the characteristics of magnetization loss in the HTS tape with a copper layer in the kHz frequency band. Therefore, we prepared GdBCO tapes with and without the copper layer and measured the magnetization loss of the GdBCO tape exposed to a vertical magnetic field in the kHz frequency band. We analyzed the ac losses of the GdBCO layer, the copper layer, and the other layers within the tape by a finite element method analysis. The influence of the copper layer thickness on the ac loss in each layer was investigated by a finite element method (FEM) analysis. The magnetization loss per cycle of the GdBCO tape slightly decreased with the frequency. The magnetization loss, however, can be approximately estimated by Brandt's formula with a certain accuracy when the n value of the tape is large. In the GdBCO tape with the copper layer, when the external magnetic field was large, the magnetization loss per cycle of the GdBCO layer was larger than the copper layer loss. The magnetization loss, however, decreased and the copper layer loss increased with the thickness of the copper layer. The total loss of the GdBCO tape can be reduced by placing the coppers layer near the GdBCO layer.

DOI： 10.1109/TASC.2018.2820734

Scopus

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

Wireless power transmission has been investigated to realize more efficient and more convenient noncontact power transmission systems for electric tramways, electric vehicles, portable telephones, and so on. Since the magnetic resonance type wireless power transmission system is often used in frequency regions of megahertz, there are some problems, such as the increase of wire resistance due to skin effect and a switching loss in converter. Therefore, it is expected to realize high-power wireless power transmission in low-frequency regions of kilohertz. In a wireless power transmission system using copper coils, however, the transmission efficiency decreases with the decrease of resonance frequency because quality factor decreases with the decrease of the resonance frequency. Therefore, we fabricated a model system using high-Temperature superconducting (HTS) double-pancake coils composed of REBCO tape and investigated the transmission efficiency characteristics to evaluate the possibility of application of the HTS coil to a high-efficiency wireless power transmission system operated in the low-frequency region of kilohertz. In the copper coil system, the transmission efficiency increases with the resonance frequency. In the HTS coil system, however, a high-efficiency transmission was obtained, even at a low-resonance frequency, due to a large quality factor at low frequency. Moreover, in the wireless power transmission system using HTS coils, the transmission efficiency was high not only at the resonance frequency but also around the resonance frequency. From these results, we believe that HTS coil can realize the high-efficiency wireless power transmission in a low-frequency region of kilohertz.

DOI： 10.1109/TASC.2016.2629263

Scopus

researchmap

Authorship：Lead author   Language：English  

researchmap

researchmap

researchmap

researchmap

researchmap

Authorship：Lead author   Language：Japanese  

researchmap

Language：Japanese  

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Cryogenic Association of Japan  

DOI： 10.2221/jcsj.58.3

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Cryogenic Association of Japan  

DOI： 10.2221/jcsj.58.11

researchmap

Language：Japanese  

researchmap

Language：Japanese  

researchmap

Language：Japanese  

researchmap

Language：Japanese  

researchmap

Language：Japanese  

researchmap

Language：Japanese  

researchmap

Authorship：Lead author  

J-GLOBAL

researchmap

Authorship：Lead author  

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

researchmap

Authorship：Lead author  

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Authorship：Lead author  

J-GLOBAL

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

J-GLOBAL

researchmap

researchmap

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

researchmap

researchmap

Authorship：Lead author  

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author   Language：Japanese   Publisher：東北大学電気通信研究所  

CiNii Article

researchmap

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author  

researchmap

researchmap

Authorship：Lead author  

researchmap

Authorship：Lead author   Language：Japanese   Publisher：パワーエレクトロニクス学会  

DOI： 10.5416/jipe.40.236

CiNii Article

researchmap

Authorship：Lead author  

researchmap

Event date： 2023.9.10 - 2023.9.15

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.9.10 - 2023.9.15

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.9.10 - 2023.9.15

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.9.3 - 2023.9.7

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.9.3 - 2023.9.7

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.9.3 - 2023.9.7

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.9.3 - 2023.9.7

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2023.5.31 - 2023.6.2

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2023.5.31 - 2023.6.2

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.23 - 2022.10.28

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2022.10.22

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.10.22

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.10.22

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.10.22

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.10.22

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.10.22

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.6.20 - 2022.6.22

Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.6.20 - 2022.6.22

Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.6.20 - 2022.6.22

Presentation type：Oral presentation (general)  

researchmap

Event date： 2022.6.20 - 2022.6.22

Presentation type：Oral presentation (general)  

researchmap

Event date： 2021.11.30 - 2021.12.2

Language：English   Presentation type：Oral presentation (general)  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2021.11.15 - 2021.11.19

Language：English   Presentation type：Poster presentation  

researchmap

Event date： 2020.12.8 - 2020.12.10

Presentation type：Oral presentation (general)  

researchmap

Event date： 2020.10.24 - 2020.11.7

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

researchmap

Language：Japanese  

researchmap

Language：Japanese  

researchmap

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

researchmap

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap