Updated on 2022/10/25

写真a

 
YAMAMOTO Masayoshi
 
Organization
Institute of Materials and Systems for Sustainability Center for Integrated Research of Future Electronics Division Professor
Graduate School
Graduate School of Engineering
Title
Professor
Contact information
メールアドレス
External link

Degree 1

  1. Ph.D. (Engineering) ( 2004.3   Yamaguchi University ) 

Research Interests 2

  1. Power Electronics

  2. パワーエレクトロニクス

Research Areas 2

  1. Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Power engineering  / Power Electronics

  2. Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Power engineering

Current Research Project and SDGs 1

  1. 次世代航空機の電動化に関する研究

Research History 6

  1. Nagoya University   Professor

    2017.5

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    Country:Japan

  2. Nagoya University

    2016.12 - 2017.4

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    Country:Japan

  3. Shimane University   Associate professor

    2011.4 - 2017.4

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    Country:Japan

  4. Shimane University   Lecturer

    2006.4 - 2011.3

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    Country:Japan

  5. サンケン電気株式会社

    2004.4 - 2006.3

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    Country:Japan

  6. Shimane University Interdisciplinary Faculty of Science and Engineering, Department of Electronic and Control Systems Engineering

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Education 1

  1. Yamaguchi University   Graduate School, Division of Science and Engineering

    - 2003

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    Country: Japan

Professional Memberships 22

  1. 自動車技術会

  2. パワーエレクトロニクス学会

  3. 電子情報通信学会

  4. 電気学会

  5. IEEE

  6. 新材料半導体パワーデバイスとその利用に関する技術協同研究委員会

  7. 新材料パワー半導体の変換器応用に関する技術協同研究委員会

  8. 平成26年電子・情報・システム部門大会実行委員会

  9. 平成26年電子・情報・システム部門大会委員会

  10. 平成28・29年度学会活動推進員〔中国支部〕

  11. 平成26・27年度学会活動推進員〔中国支部〕 ・電気学会

  12. 平成24年全国大会実行委員会

  13. 島根県パワーエレクトロニクス研究会

  14. 商用電源にインターフェイスされる電力変換システム技術調査専門委員会・電気学会

  15. 交流電源インターフェイス用コンバータ技術調査専門委員会 ・電気学会

  16. 交流電源にインタフェースされるパワーエレクトロニクス回路技術調査専門委員会

  17. 中国支部役員会・電気学会

  18. ワイヤレス電力伝送システムにおける電力変換技術協同研究委員会

  19. 論文委員会(D1グループ) ・電気学会

  20. 自動車用パワーエレクトロニクスの適用調査専門委員会

  21. 自動車用パワーエレクトロニクスの新展開調査専門委員会

  22. 自動車用パワーエレクトロニクスの拡大調査専門委員会

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Committee Memberships 18

  1. 論文委員会(D6グループ)   委員  

    2020.1   

  2. 選挙管理委員会   委員  

    2019.10 - 2021.6   

  3. 総務会議   委員 東海 総務担当  

    2019.5 - 2020.6   

  4. 電動車両のパワーコントロールユニットの高性能化に関する協同研究委員会   委員  

    2019.4 - 2021.3   

  5. ICEMS2020実行委員会   委員  

    2019.4 - 2021.3   

  6. 広報委員会   委員  

    2018.6 - 2019.5   

  7. 編修専門第3部会   委員  

    2018.5 - 2020.6   

  8. 東海支部役員会   総務企画幹事  

    2018.5 - 2020.6   

  9. SiCとGaNと共に発展するパワーエレクトロニクスにおけるシステムインテグレーション技術調査   委員  

    2018.4 - 2021.3   

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    Committee type:Academic society

  10. 交流電源にインタフェースされる電力変換回路および制御技術調査専門委員会   幹事  

    2018.4 - 2020.3   

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    Committee type:Academic society

  11. 平成30・31年度学会活動推進員〔東海支部〕   総務企画幹事  

    2018.4 - 2020.3   

  12. 日本学術振興会 産学協力研究委員会   副委員長  

    2016.10   

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    Committee type:Academic society

  13. 平成28・29年度学会活動推進員〔中国支部〕   推進員(学校)  

    2016 - 2018   

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    Committee type:Academic society

    平成28・29年度学会活動推進員〔中国支部〕

  14. IPEC2018組織委員会   委員  

    2015.12 - 2019.3   

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    Committee type:Academic society

  15. IPEC2018組織委員会   委員  

    2015 - 2019   

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    Committee type:Academic society

    IPEC2018組織委員会

  16. 自動車用パワーエレクトロニクスの新展開調査専門委員会   委員  

    2015 - 2017   

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    Committee type:Academic society

    自動車用パワーエレクトロニクスの新展開調査専門委員会

  17. 新材料パワー半導体の変換器応用に関する技術協同研究委員会   委員長  

    2015 - 2017   

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    Committee type:Academic society

    新材料パワー半導体の変換器応用に関する技術協同研究委員会

  18. 電気学会半導体電力変換技術委員会   1号委員  

    2014.1   

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    Committee type:Academic society

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Awards 3

  1. 優秀論文発表賞

    2022.2   電気学会 半導体電力変換研究会   直流ブラシモータにおけるスパイクサージ の分析と解析モデルの提案

    片桐高大

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  2. 電気学会優秀論文発表賞

    2022.1   電気学会  

    塩山 知

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  3. 第16回WPT研コンテスト 優秀賞

    2020.11   WPT研究会   電界&磁界ハイブリッド結合!!反射波も利用できる 走れ!オメガ・ヴィークル

    蔵本 大樹、大矢 根蒼、大野 広道、山本 真義様

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    Country:Japan

 

Papers 102

  1. A simple gate driver design for GaN-based switching devices with improved surge voltage and switching loss at 1 MHz operation International coauthorship International journal

    Jodo Shota, Iwaki Toshihiro, Uchiyama Kosuke, Islam Md. Zahidul, Kataoka Kensuke, Hayakasa Yuki, Imaoka Jun, Yamamoto Masayoshi, Niitsu Kiichi

    JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 60 ( SA )   2021.1

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    Language:English  

    Web of Science

  2. Effect of Tunnel Pits Radius Variation on the Electric Characteristics of Aluminum Electrolytic Capacitor Reviewed International journal

    IEICE TRANSACTIONS ON ELECTRONICS   Vol. E104C ( 1 ) page: 22 - 33   2021.1

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    Authorship:Last author   Language:English  

    DOI: 10.1587/transele.2020ECP5009

    Web of Science

  3. Effects of Secondary Leakage Inductance on the LLC Resonant Converter Reviewed International coauthorship International journal

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

    IEEE TRANSACTIONS ON POWER ELECTRONICS   Vol. 35 ( 1 ) page: 835 - 852   2020.1

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  4. Current and Voltage Hybrid Source Gate Driver for Maximizing the Switching Capability of SiC MOSFETs Reviewed International journal

    Ishido Ryosuke, Okawauchi Yuta, Nakahara Ken, Shirai Shinya, Yamamoto Masayoshi

    2020 IEEE WORKSHOP ON WIDE BANDGAP POWER DEVICES AND APPLICATIONS IN ASIA (WIPDA ASIA)     2020

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    Authorship:Last author   Language:English  

    DOI: 10.1109/WiPDAAsia49671.2020.9360286

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  5. Improved core loss calculation method considering the non-uniform distribution of magnetic flux density in powder cores Reviewed International coauthorship International journal

    Ishikura Yuki, Imaoka Jun, Noah Mostafa, Yamamoto Masayoshi

    IET POWER ELECTRONICS   Vol. 12 ( 6 ) page: 1393 - 1399   2019.5

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    Authorship:Last author   Language:English  

    DOI: 10.1049/iet-pel.2018.5362

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  6. 13.56MHz Half-Bridge GaN-HEMT Resonant Inverter Achieving High Power, Low Distortion, and High Efficiency by ‘L-S Network’

    OYANE Aoi, SENANAYAKE Thilak, MASUDA Mitsuru, IMAOKA Jun, YAMAMOTO Masayoshi

    IEICE Transactions on Electronics   Vol. E105C ( 9 ) page: 407 - 418   2022.9

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    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    <p>This paper proposes a topology of high power, MHz-frequency, half-bridge resonant inverter ideal for low-loss Gallium Nitride high electron mobility transistor (GaN-HEMT). General GaN-HEMTs have drawback of low drain-source breakdown voltage. This property has prevented conventional high-frequency series resonant inverters from delivering high power to high resistance loads such as 50Ω, which is typically used in radio frequency (RF) systems. High resistance load causes hard-switching also and reduction of power efficiency. The proposed topology overcomes these difficulties by utilizing a proposed ‘L-S network’. This network is effective combination of a simple impedance converter and a series resonator. The proposed topology provides not only high power for high resistance load but also arbitrary design of output wattage depending on impedance conversion design. In addition, the current through the series resonator is low in the L-S network. Hence, this series resonator can be designed specifically for harmonic suppression with relatively high quality-factor and zero reactance. Low-distortion sinusoidal 3kW output is verified in the proposed inverter at 13.56MHz by computer simulations. Further, 99.4% high efficiency is achieved in the power circuit in 471W experimental prototype.</p>

    DOI: 10.1587/transele.2021ECP5048

    Web of Science

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  7. Spike Surge and Conducted EMI Simulation of DC Brush Motor Considering Steady Arc at Mechanical Contacts

    Katagiri Kodai, Ogawa Toru, Yamamoto Masayoshi, Imaoka Jun, Sasaki Mamoru

    IEEJ Transactions on Industry Applications   Vol. 142 ( 7 ) page: 490 - 497   2022.7

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    <p>This study provides a circuit analysis model of a DC brush motor to predict spike surges at mechanical contacts and conducted EMI by considering the behavior of steady arc discharge. The mechanical contacts model comprises multiple variable resistors, constant voltage sources, ideal diodes, and stray capacitances. In the proposed model, spike surges with steady arc could be predicted with 90% accuracy. Moreover, simulated conducted EMI according to CISPR 25 standard is deviated from the measured value at a maximum of 25dB. Therefore, it is demonstrated that the quantitative prediction of conducted EMI requires consideration of a showering arc model at mechanical contacts.</p>

    DOI: 10.1541/ieejias.142.490

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  8. An Evaluation of a New Type of High Efficiency Hybrid Gate Drive Circuit for SiC-MOSFET Suitable for Automotive Power Electronics System Applications

    YAMAMOTO Masayoshi, SHIRAI Shinya, THILAK Senanayake, IMAOKA Jun, ISHIDO Ryosuke, OKAWAUCHI Yuta, NAKAHARA Ken

    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences   Vol. E105A ( 5 ) page: 834 - 843   2022.5

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    Language:Japanese   Publisher:The Institute of Electronics, Information and Communication Engineers  

    <p>In response to fast charging systems, Silicon Carbide (SiC) power semiconductor devices are of great interest of the automotive power electronics applications as the next generation of fast charging systems require high voltage batteries. For high voltage battery EVs (Electric Vehicles) over 800V, SiC power semiconductor devices are suitable for 3-phase inverters, battery chargers, and isolated DC-DC converters due to their high voltage rating and high efficiency performance. However, SiC-MOSFETs have two characteristics that interfere with high-speed switching and high efficiency performance operations for SiC MOS-FET applications in automotive power electronics systems. One characteristic is the low voltage rating of the gate-source terminal, and the other is the large internal gate-resistance of SiC MOS-FET. The purpose of this work was to evaluate a proposed hybrid gate drive circuit that could ignore the internal gate-resistance and maintain the gate-source terminal stability of the SiC-MOSFET applications. It has been found that the proposed hybrid gate drive circuit can achieve faster and lower loss switching performance than conventional gate drive circuits by using the current source gate drive characteristics. In addition, the proposed gate drive circuit can use the voltage source gate drive characteristics to protect the gate-source terminals despite the low voltage rating of the SiC MOS-FET gate-source terminals.</p>

    DOI: 10.1587/transfun.2021GCI0001

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  9. Analysis of DC Brush Motor Spike Surge and Proposal of a Simulation Model Based on an Equivalent Circuit

    Katagiri Kodai, Ogawa Toru, Yamamoto Masayoshi, Imaoka Jun, Sasaki Mamoru, Noda Kazuhiro

    IEEJ Transactions on Industry Applications   Vol. 142 ( 3 ) page: 167 - 176   2022.3

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    <p>This paper presents a circuit analysis model to predict spike surges at mechanical contacts of a DC brush motor. Measured spike surge waveforms are classified into four types depending on the existence of a steady arc and a showering arc. The directly open without arcs condition is clarified to be the maximum spike surge voltage condition. Additionally, an equivalent circuit model is developed to simulate spike surges. This model considers complex high-frequency characteristics and rotation angle dependence of impedances. A full-slot equivalent circuit model is represented by a combination of single-slot models. The spike surge simulation model considers induced voltage and variable resistors representing mechanical contact switching in addition to impedance characteristics. The simulated spike surges show good quantitative agreement with the measured values.</p>

    DOI: 10.1541/ieejias.142.167

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  10. Transformer with Adjustable Path-Core Type Inductance for Use in GaN-HEMT LLC Resonant Converter

    Ou Tengfei, Noah Mostafa, Tsuruya Mamoru, Namiki Seiji, Morita Koichi, Imaoka Jun, Yamamoto Masayoshi

    IEEJ Journal of Industry Applications   Vol. 11 ( 1 ) page: 41 - 48   2022

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    <p>A novel magnetic structure for use in LLC resonant converters is proposed in this paper. It is known as a Path-core type Resonant Inductance Adjustable (PRIA) transformer, which is a type of transformer with adjustable resonant inductance. In the proposed transformer, the resonant inductance and magnetizing inductance can be designed separately; therefore, it becomes less challenging to realize the required resonant frequency. Moreover, the magnetizing inductance is not affected by any variation in the resonant inductance. The proposed PRIA transformer is found to improve the efficiency of the LLC converters. In this paper, the design of a resonant inductance of a PRIA transformer is presented. In addition, the application of PRIA transformers to a 1-MHz LLC resonant converter and 1kW 1.4-MHz LLC resonant converter is presented.</p>

    DOI: 10.1541/ieejjia.21002488

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  11. An Investigation and Proposal for Accurate Leakage Inductance Modeling Based on Dowell Model

    Wu Y.H., Shigematsu K., Omoto Y., Imaoka J., Yamamoto M.

    2022 International Power Electronics Conference, IPEC-Himeji 2022-ECCE Asia     page: 1964 - 1969   2022

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    Language:Japanese   Publisher:2022 International Power Electronics Conference, IPEC-Himeji 2022-ECCE Asia  

    The aim of this research is to build a highly applicable, accurate, and fast leakage inductance modeling method based on Dowell model. Which is a widely used analytical modeling method to estimate AC resistance and leakage inductance. Since most of the literatures use Dowell model basically with the limited condition achieving ac-curate modeling of leakage inductance, in this research, an accuracy investigation is conducted with the samples of EE-core transformers by finite element method (FEM) simulation and practical transformers to find the inaccurate modeling related to the geometrical characteristic. After that, a proposed hybrid modeling using artificial neural network (ANN) is conducted to create a black box error correction model of conventional Dowell model with FEM results. As the result, the modeling shows high accuracy by Dowell with ANN error correction model. It carries out the future to develop a modified Dowell model by analyzing the ANN error correction model. Which can describe the geometrical characteristic of transformer accurately.

    DOI: 10.23919/IPEC-Himeji2022-ECCE53331.2022.9807009

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  12. Common Mode Noise Reduction of Two-Phase Interleaved Boost Converters with Integrated Magnetics Utilizing Balanced Technique

    Nagai T., Sasaki M., Imaoka J., Yamamoto M., Nakano A.

    2022 International Power Electronics Conference, IPEC-Himeji 2022-ECCE Asia     page: 746 - 752   2022

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    Language:Japanese   Publisher:2022 International Power Electronics Conference, IPEC-Himeji 2022-ECCE Asia  

    High-power density and high efficiency in boost converters are required in several applications such as motor drive systems in eco-friendly vehicles and power conditioning systems used in renewable energy systems. To realize these requirements, applying compound semiconductor devices such as GaN and SiC are attractive options because they can drive at high-switching frequency with low power losses, and it is known to contribute to the miniaturization of passive devices. However, when driving power devices with high switching speed at high-switching frequency, EMI (Electro-Magnetic Interference) noise with a wide spectrum is produced. To attenuate EMI noise, large EMI filters have to be equipped. When using large EMI filters, the downsizing effect of power converters is reduced. To countermeasure the above problem, this paper proposes interleaved boost converter with integrated magnetics capable of Common-Mode (CM) noise reduction without adding EMI filters. The noise reduction is realized by the balanced technique, which is known as an effective noise reduction technique from a circuit topology perspective. In addition, interleaved circuit topology and integrated magnetics are contributed to realizing high-power density converters. The effectiveness of the proposed converters is discussed from simulation and experimental viewpoints.

    DOI: 10.23919/IPEC-Himeji2022-ECCE53331.2022.9806834

    Scopus

  13. A Magnetic Design Method for Powder Core Inductor with Concentrated Airgap Considering DC Superposition Characteristics Used for High Current Applications

    Imaoka J., Yu-Hsin W., Shigematsu K., Noah M., Yamamoto M., Martinez W.

    2021 23rd European Conference on Power Electronics and Applications, EPE 2021 ECCE Europe     2021.9

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    Language:Japanese   Publisher:2021 23rd European Conference on Power Electronics and Applications, EPE 2021 ECCE Europe  

    Powder cores are attractive magnetic cores for high current applications such as bidirectional dc/dc converters used in power trains of eco-friendly automotive because of their high saturation flux density, high Curie temperature, and soft saturation characteristics. However, powder cores have nonlinear relative permeability characteristics dependent on the magnetic field intensity which results in a drop in the inductance value at high current values. There are two key solutions to keep constant inductance value at maximum power rating of circuit specifications: (1) inserting a concentrated airgap (2) reducing the number of turns to tackle the drop of relative permeability due to dc-bias. Therefore, this paper proposes a novel magnetic design method for powder core inductors with concentrated airgap which to keep the desired inductance constant under dc-bias conditions. The feature of the proposed design methodology is based on considering non-linear relative permeability directly based on the magnetic characteristics modeling. The validity of the proposed method is confirmed by experimental tests using EE core.

    Scopus

  14. Cooperative Control of Multi-Input Modular DC/DC Converter for Electric Off-Highway Vehicles

    Piao Qingyun, Kakisaka Tasuku, Imaoka Jun, Yamamoto Masayoshi, Konoto Masaaki

    IEEJ Transactions on Industry Applications   Vol. 141 ( 4 ) page: 304 - 312   2021.4

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    <p>A cooperative control scheme for a power conversion system having several energy sources and modular dc/dc converters is proposed in this paper. The proposed cooperative control approach has the advantage of realizing constant dynamic characteristics even when the different input voltages fluctuate or when the output power of each input voltage source is limited. The effectiveness of the proposed cooperative control method is verified via simulation and experiment.</p>

    DOI: 10.1541/ieejias.141.304

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  15. Improvement of the Transmission Efficiency in the Electric Field Resonance Wireless Power Transmission by Utilizing Helical Resonators

    OYANE Aoi, YAMAMOTO Masayoshi

      Vol. J104-B ( 3 ) page: 309 - 311   2021.3

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    The efficiency of electric field resonance wireless power transmission (WPT) is low in long distances. However, the proposed system realizes high efficiency in long distances by utilizing high-Q helical resonators. The transmission efficiency of the proposed system is increased by at most 69.4% compared with the conventional system at 27.12MHz.

    DOI: 10.14923/transcomj.2020gwl0001

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  16. A Novel Power Loss Calculation Method for Power Magnetic Components in Power Converters

    Ishikura Yuki, Hosotani Tatsuya, Yamamoto Masayoshi

    IEEJ Transactions on Fundamentals and Materials   Vol. 141 ( 1 ) page: 69 - 75   2021.1

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    <p>This paper reports a power loss calculation method for magnetic components in power converters. The differences in B-H loop areas are analyzed and discussed in case of sinusoidal waveform and square wave voltage excitation. Relying on the output results, iron loss calculation method based on square wave excitation is proposed. Experimental results show that the proposed iron loss calculation method is accurate compared with the traditional method using Steinmetz's equation. In addition, the proposed method reduces the calculation procedure compared with the method using Steinmetz's equation. The proposed iron loss calculation method is very practical and beneficial for converter designers.</p>

    DOI: 10.1541/ieejfms.141.69

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  17. A simple gate driver design for GaN-based switching devices with improved surge voltage and switching loss at 1 MHz operation

    Jodo S., Iwaki T., Uchiyama K., Islam M.Z., Kataoka K., Hayakasa Y., Imaoka J., Yamamoto M., Niitsu K.

    Japanese Journal of Applied Physics   Vol. 60 ( SA )   2021.1

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    Language:Japanese   Publisher:Japanese Journal of Applied Physics  

    In power electronics, the impedance of reactance components increases proportionally with frequency; therefore, the sizes of reactance components can be reduced by increasing the switching frequency. Gallium nitride (GaN)-based devices have received significant attention in high-frequency applications because the figure-of-merit of GaN is superior to that of silicon (Si). However, for high-frequency operation, a trade-off relationship between the surge voltage induced by parasitic inductances, and the switching loss becomes significant. Therefore, in this study, we propose a gate driver that improves the trade-off relationship. This gate driver was obtained via the addition of simple logic circuits and capacitors to a conventional gate driver. The effectiveness of our proposed circuit was verified via SPICE simulations with Cadence Spectre using 180 nm CMOS technology. The simulation results show that by operating at 1 MHz, this circuit can help reduce the surge voltage by 12.2% and the switching loss by 14.3%.

    DOI: 10.35848/1347-4065/abbdc7

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  18. Bidirectional Converter with Multi-stage FETs Featuring Voltage Balance Control Function Using Variable Capacitors

    Ishikura Yuki, Hosotani Tatsuya, Yamamoto Masayoshi

    IEEJ Journal of Industry Applications   Vol. 10 ( 1 ) page: 100 - 106   2021

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    Language:Japanese   Publisher:The Institute of Electrical Engineers of Japan  

    <p>This paper presents a bidirectional converter with multi-stage FETs featuring voltage balance control function using variable capacitors. The proposed converter is constructed using low-voltage Si-FETs in a series connection, and it improves the voltage balance between the drain-source voltages of the series connected FETs in the OFF period. Using the converter figure of merit (FOM), which can estimate the converter losses from the specifications of the FETs, the effectiveness of the proposed converter is compared to that of a converter using SiC-FETs. The factors of the voltage unbalance are analytically clarified using the equivalent circuit. The principle of voltage balance control function using the variable capacitor is discussed. The experimental results show that the proposed converter can achieve a maximum power conversion efficiency of 99.2%.</p>

    DOI: 10.1541/ieejjia.19003873

    Web of Science

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  19. Reversed Configuration Boost Converter to Reduce Effective CM Capacitance

    Sasaki Mamoru, Imaoka Jun, Yamamoto Masayoshi

    2021 IEEE INTERNATIONAL FUTURE ENERGY ELECTRONICS CONFERENCE (IFEEC)     2021

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    Language:Japanese   Publisher:2021 IEEE International Future Energy Electronics Conference, IFEEC 2021  

    More and more wide band gap power devices are used in switching converters to achieve high power density and high efficiency. However,those devices increase electromagnetic interference (EMI),especially common mode (CM) noise propagates through parasitic capacitance. A noise filter is a popular way to decrease EMI. But a filter decreases the power density of the converter because of the bulk components. Therefore,a noise reduction method with small increase in volume and weight is necessary. In this paper,a novel but simple circuit configuration for high power application to reduce CM noise is investigated in simulation and experiment.

    DOI: 10.1109/IFEEC53238.2021.9662002

    Web of Science

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  20. Time-Shifted Control of Self-Synchronous Rectifier For MHz Wireless Power Transfer Systems

    Sasaki Masato, Sakuno Keiichi, Yamamoto Masayoshi

    PROCEEDINGS OF 2021 IEEE 30TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE)   Vol. 2021-June   2021

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    Language:Japanese   Publisher:IEEE International Symposium on Industrial Electronics  

    Recently wireless power transfer systems via resonant magnetic coupling (MRC-WPT) is the promising wireless power supply method to mobile applications. 13.56MHz highly resonant wireless power receivers experience high rectifier losses when using Schottky diodes and can fail to meet the thermal limit requirements for many products such as laptops. Therefore, the synchronous rectification is one of the effective solutions. However, the increased occupancy of the control signal propagation delay in switching cycle, tend to make the introduction of the synchronous rectification difficult. This novel synchronous rectifier can operate under any propagation delay of gate drivers. The analysis successfully verified the operating principle and clarified the usefulness of the proposed control for MHz WPT systems.

    DOI: 10.1109/ISIE45552.2021.9576180

    Web of Science

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  21. EMI Analysis and Suppression Method Using Ferrite Beads Applied to LLC Converter

    Okochi Rino, Takatsuji Hiroyuki, Imaoka Jun, Yamamoto Masayoshi

    2021 IEEE INTERNATIONAL FUTURE ENERGY ELECTRONICS CONFERENCE (IFEEC)     2021

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    Language:Japanese   Publisher:2021 IEEE International Future Energy Electronics Conference, IFEEC 2021  

    To operate the LLC converter at high switching frequency,the excitation current flowing through the transformer is increased,which generates a large conducted noise. The peaks in the noise spectrum are caused by the ringing of the switching node voltage and the resonance of the CM equivalent circuit. In this paper,a method using ferrite beads and additional resistors in combination with the input filter is proposed to suppress the ringing. Its effectiveness in reducing the high-frequency noise while maintaining the fast-switching speed is confirmed by simulation and experiment.

    DOI: 10.1109/IFEEC53238.2021.9661804

    Web of Science

    Scopus

  22. Analysis on Parasitic Capacitance to Prevent False Turn-on in GaN HEMT

    Iwaki Toshihiro, Sawada Takashi, Imaoka Jun, Yamamoto Masayoshi

    2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)     page: 5616 - 5621   2021

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    Driving power devices such as GaN HEMTs at high-frequency is one of the successful solutions to miniaturize the magnetic components of circuits. On the other hand, GaN HEMTs have drawbacks in high-speed switching. For example, in a full-bridge inverter configuration, a fast turn-on of one power device can cause a false turn-on of the complementary power device. Therefore, the GaN HEMT might be destroyed by the overcurrent and transient heat caused by the short circuit. The most important factor for the false turn-on of GaN HEMTs is its reverse transfer capacitance (Crss), but other parasitic components such as inductances in PCB should be considered to analyze the false turn-on phenomena. In this paper the theoretical analysis of the capacitance components that may cause the false turn-on is conducted. Based on the theoretical analysis, we propose the conditions of the parasitic component of the gate drive circuit to prevent false turn-on.

    DOI: 10.1109/ECCE47101.2021.9595846

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    Scopus

  23. A Novel Measurement Method for DC Superimposition Characteristics of Three-Phase Coupled Inductors with Powder Cores

    Mishima Yamato, Aoki Tatsuya, Matsuta Kazuya, Imaoka Jun, Yamamoto Masayoshi, Yoshimoto Kosuke

    2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)     page: 5334 - 5341   2021

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    the objective of this research is to build the measurement method of DC superimposition of multiphase coupled inductors with powder cores. From a perspective of magnetic material, powder cores are usually applied to inductor core in high current applications such as E-mobility due to their attractive features. In addition, multiphase DC/DC converters with coupled inductors can effectively downsize passive components that occupy significant space in power converters. However, when applying coupled inductor with powder cores under the dc current superimposed condition, self-inductance and mutual inductance values of coupled inductors are varied depending on dc current values. Furthermore, measurement methods of the dc superimposition characteristics of multiphase coupled inductor have not been discussed in the relevant literature. Therefore, this paper proposes two measurement methods for DC superimposition characteristics of three-phase coupled inductors with powder cores used in three-phase DC-DC converters. The first method is for three-phase coupled inductors with an asymmetric magnetic core structure, and the values of each self-inductance and mutual inductance can be measured separately. The second method is a simplified measurement method limited to multiphase coupled inductors with symmetric magnetic core structures. DC superimposition characteristics of coupled inductors can be measured with a smaller number of measurements than the first method, and it can be extended to N phase coupled inductors. The verification of the two methods has been evaluated through simulation and experiment.

    DOI: 10.1109/ECCE47101.2021.9595692

    Web of Science

    Scopus

  24. A Magnetic Design Method for Powder Core Inductor with Concentrated Airgap Considering DC Superposition Characteristics Used for High Current Applications

    Imaoka Jun, Yu-Hsin Wu, Shigematsu Koichi, Noah Mostafa, Yamamoto Masayoshi, Martinez Wilmar

    2021 23RD EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'21 ECCE EUROPE)     2021

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    Web of Science

  25. 13.56MHz high power half-bridge GaN-HEMT resonant inverter achieving 99% power efficiency

    Oyane A., Senanayake T., Hattori F., Imaoka J., Yamamoto M., Masuda M.

    9th IEEE International Conference on Power Electronics, Drives and Energy Systems, PEDES 2020     2020.12

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    High-power inverters with high frequency have been required for progressing technologies such as wireless power transfer (WPT) and plasma processing. Recently, gallium nitride high electron mobility transistor (GaN-HEMT) is getting lots of attention from the viewpoint of fast switching ability and low power consumption. However, GaN-HEMT inverters are difficult to be operated in over several kW because of its low drain-source breakdown voltage. In other words, the conventional half-bridge GaN-HEMT inverter can output high power only for the small load resistance less than several-O. This paper overcomes this difficulty by implementing an impedance conversion network in the prior stage of the series resonator. The proposed topology realizes not only high-power from low drain-source voltage but also the sine wave output with very low harmonics. 3kW output to 50O load at 13.56MHz is theoretically designed, and verified by computer simulations. And also, the experimental prototype using GaN-HEMTs achieves the high efficiency of 99.43% at 13.56MHz and 471W.

    DOI: 10.1109/PEDES49360.2020.9379451

    Scopus

  26. Magnetic Design Method for Multi-Material Inductor to Flatten Efficiency Curve of Power Converters within Wide Load Ranges Invited Reviewed

    Ishikura Y, Imaoka J., Noah M., Aoki T, Ito K, Yamamoto M

    IEEE Transactions on Magnetics   Vol. 56 ( 10 ) page: 1 - 8   2020.10

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  27. Magnetic Design Method for Multi-Material Inductor to Flatten Efficiency Curve of Power Converters Within Wide Load Ranges Reviewed International coauthorship International journal

    Ishikura Yuki, Imaoka Jun, Noah Mostafa, Aoki Tatsuya, Ito Koichiro, Yamamoto Masayoshi

    IEEE TRANSACTIONS ON MAGNETICS   Vol. 56 ( 10 )   2020.10

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  28. Output Power Pulsation Suppressed with an Activity Smoothen Buck-Boost Converter to Achieve Electrolytic Capacitor-less AC/DC Converter

    Ou T., Namiki S., Tsuruya M., Noah M., Morita K., Mukaiyama D., Imaoka J., Yamamoto M.

    12th AEIT International Annual Conference, AEIT 2020     2020.9

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    An Activity Smoothen Circuit with bidirectional Buck-Boost Converter (AS-BBC) was approached to smoothen the output power of a power factor correction (PFC) converter, which is an AC/DC converter, without using any electrolytic capacitors in this paper. In order to smoothen the output pulsation current of the PFC converter, electrolytic capacitors have been used generally, since electrolytic capacitors have a large magnitude capacity. However, there is a lifespan to electrolytic capacitors. On the other hand, film capacitors have a semi-permanent lifespan with so much less magnitude capacity than electrolytic capacitors. A way of using the AS-BBC to make a small capacitor work like a large capacitor as a smoothing capacitor to handle the output power is presented in this paper. Approximately 47% of the pulsation output is suppressed with a 4.4μ F film capacitor with the AS-BBC. Since there is no electrolytic capacitor adapted, a semi-permanent lifespan PFC converter is achieved successfully.

    DOI: 10.23919/AEIT50178.2020.9241166

    Scopus

  29. Temperature Dependency Modeling, Simulation and Experimental Validations of DC Superimposition Characteristics for Gapped-Ferrite Inductor Including Saturation Region

    Imaoka J., Aoki T., Shigematsu K., Yamamoto M.

    IEEE International Symposium on Industrial Electronics   Vol. 2020-June   page: 1466 - 1473   2020.6

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    To realize the early development of power converters, research on the front-loading design in which the efficiency, control characteristics, converter size, thermal management, and Electromagnetic Compatibility (EMC) are carefully considered before making a prototype, has been attracting. To carefully design and predict these design factors before prototyping, making accurate models of active/passive components operated on simulation of the multi-physical domain such as thermal, magnetic, and electrical is indispensable. This is because these characteristics of active/passive components on power converters are affected by each other. In this background, this paper proposes a nonlinear relative permeability modeling method with a temperature dependency of gapped-ferrite cores. The temperature dependency of the effective relative permeability of the gapped-ferrite core is investigated under core temperature within-50°C-+ 150°C. As features of the proposed modeling method and simulation model, a simple mathematical equation and lookup tables are utilized for simple implementation to the simulator. The validity of the proposed modeling method is confirmed by both simulation and experimental tests under operating conditions including the magnetic saturation regions.

    DOI: 10.1109/ISIE45063.2020.9152521

    Scopus

  30. Analysis of Common Mode Noise Reduction Mechanism in A Shielded Inductor

    Sasaki M., Imaoka J., Yamamoto M., Nakano A., Fuse K.

    IEEE International Symposium on Industrial Electronics   Vol. 2020-June   page: 660 - 665   2020.6

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    To achieve high power density, a power converter circuit is often operated at high frequency, and fast switching devices are also combined to reduce switching loss. On the other hand, both high frequency and fast switching greatly increases conductive noise amplitude at frequency over several megahertz. Therefore, electromagnetic compatibility (EMC) is necessary for a high power density converter. However, an additional filter, which consists of large and heavy passive elements, greatly degrades power density. Thus, in this paper, a noise reduction method for noise at frequency band over 10 MHz with small volume increase is presented and investigated. Consequently, the simulation and experimental result verifies that the proposed method decreases MHz-band noise with small volume increase.

    DOI: 10.1109/ISIE45063.2020.9152408

    Scopus

  31. Comparison of switching performance between GaN and SiC MOSFET via 13. 56MHz Half-bridge Inverter

    Xiong Y., Oyane A., Ou T., Thilak S., Imaoka J., Yamamoto M.

    IEEE International Symposium on Industrial Electronics   Vol. 2020-June   page: 672 - 676   2020.6

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    Both silicon-carbide (SiC) and gallium-nitride (GaN) are wide bandgap power transistor which are developing rapidly. They are able to be used as the main switches in the high-frequency power conversion systems successfully. These high-frequency switches just meet the high demand of low-size power electronics device in recent years. As the high-frequency system always relies on the switches, we designed and made evaluation boards for both SiC and GaN switches by 13. 56MHz half-bridge inverter. Both simulation and experimental results show that GaN achieved more successfully switching, which made good output waveform with very short dead-time. And in simulation, lower switching loss of GaN is also confirmed. As all above, it is obvious that GaN device is more suitable for high-frequency application.

    DOI: 10.1109/ISIE45063.2020.9152253

    Scopus

  32. Technical Trend of Power Electronics Systems for Automotive Applications Invited Reviewed

    Yamamoto M., Kakisaka T, Imaoka J

    Japanese Journal of Applied Physics   Vol. 59 ( SG ) page: 0805-1 - 0805-13   2020.4

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  33. 多段FET駆動技術を用いた双方向コンバータ Invited Reviewed

    石倉祐樹 ,細谷達也, 山本 真義

    電子情報通信学会論文誌 B   Vol. J103-B ( No.4 ) page: .154 - 161   2020.4

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  34. Technical trend of power electronics systems for automotive applications Reviewed International journal

    JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

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  35. Bidirectional Converter Using Multi-stage FET Driving Technique

    ISHIKURA Yuki, HOSOTANI Tatsuya, YAMAMOTO Masayoshi

      Vol. J103-B ( 4 ) page: 154 - 161   2020.4

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    This paper presents a bidirectional converter using by multi-stage FET driving technique. The proposed converter is constructed by implementing series connected low voltage Si-FETs in multi-stage. A driving circuit using multi-stage driving technique can drive series connected FETs from the one power supply without any isolated power supplies and high voltage process ICs. In addition, the balancing capacitors which constructed the converter have voltage averaging function in drain-source voltage to tackle the voltage unbalance between the series connected FETs. Using the figure of merit which can estimate converter losses from the specification of power devices, the usefulness of the circuit configuration which using low voltage Si-FETs instead of SiC-FETs is shown. The effect of the voltage averaging function by the balancing capacitors, the operating principle of the driving circuit and the power conversion mechanism are clarified and presented using the circuit simulator and a converter equivalent circuit. The experimental results show that the proposed driving technique allows the bidirectional converter to achieve a maximum power conversion efficiency of 99.2%.

    DOI: 10.14923/transcomj.2019jbp3022

    CiNii Research

  36. Bidirectional Converter with Multi-stage FETs Featuring Voltage Balance Control Function Using Variable Capacitors

    Ishikura Yuki, Hosotani Tatsuya, Yamamoto Masayoshi

    IEEJ Transactions on Industry Applications   Vol. 140 ( 3 ) page: 168 - 174   2020.3

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    <p>This paper presents a bidirectional converter with multi-stage FETs featuring voltage balance control function using variable capacitors. The proposed converter is constructed using low-voltage Si-FETs in a series connection, and it improves the voltage balance between the drain-source voltages of the series connected FETs in the OFF period. Using the converter figure of merit (FOM), which can estimate the converter losses from the specifications of the FETs, the effectiveness of the proposed converter is compared to that of a converter using SiC-FETs. The factors of the voltage unbalance are analytically clarified using the equivalent circuit. The principle of voltage balance control function using the variable capacitor is discussed. The experimental results show that the proposed converter can achieve a maximum power conversion efficiency of 99.2%.</p>

    DOI: 10.1541/ieejias.140.168

    Scopus

    CiNii Research

  37. Voltage Balancing Control Method Using Variable Capacitors with Simple Turn-on Adjusting Function for Multi-Stage FET Bidirectional Converter

    Ishikura Y., Hosotani T., Noah M., Imaoka J., Yamamoto M.

    Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC   Vol. 2020-March   page: 2944 - 2949   2020.3

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    This paper proposes a voltage balancing control method using variable capacitors with simple turn-on adjusting function for multi-stage FET bidirectional converter. The proposed voltage balancing control circuit is composed of a feedback circuit using photocouplers and a delay circuit using variable capacitors with turn-on adjusting diodes. The proposed voltage balancing circuit can reduce the drain-source voltage unbalance which occur during the turn-on and turn-off period of series-connected FETs. The theoretical discussion includes analyzing the unbalanced drain-source voltage in seriesconnected FETs using a simplified converter. Also, the principal of the proposed voltage balancing control method is clarified. The experimental results show that the proposed voltage balancing control method can reduce the drain-source voltage difference Δvds of series-connected FETs from 36 V to 11 V (69% reduction in Δvds) during the turn-off and from 22 V to 11 V (50% reduction in Δvds) during the turn-on period. The multistage FET bidirectional converter can achieve a maximum power conversion efficiency of 99.2%.

    DOI: 10.1109/APEC39645.2020.9124221

    Scopus

  38. A simple gate driver design for GaN-based switching devices with improved surge voltage and switching loss at 1-MHz operation Invited Reviewed

    Shota Jodo, Toshihiro Iwaki, Kosuke Uchiyama, Md. Islam, Kensuke Kataoka, Yuki Hayasaka, Jun Imaoka, Masayoshi Yamamoto, Kiichi Niitsu

    Japanese Journal of Applied Physics   Vol. No. 60 ( SADD02 ) page: SAAD02-1 - SAAD02   2020

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  39. Comparison of switching performance between GaN and SiC MOSFET via 13.56MHz Half-bridge Inverter

    Xiong Yi, Oyane Aoi, Ou Tengfei, Thilak Senanayake, Imaoka Jun, Yamamoto Masayoshi

    2020 IEEE 29TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE)     page: 672 - 676   2020

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    Web of Science

  40. Analysis of Common Mode Noise Reduction Mechanism in A Shielded Inductor

    Sasaki Mamoru, Imaoka Jun, Yamamoto Masayoshi, Nakano Akira, Fuse Koji

    2020 IEEE 29TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE)     page: 660 - 665   2020

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  41. Temperature Dependency Modeling, Simulation and Experimental Validations of DC Superimposition Characteristics for Gapped-Ferrite Inductor Including Saturation Region

    Imaoka Jun, Aoki Tatsuya, Shigematsu Koichi, Yamamoto Masayoshi

    2020 IEEE 29TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE)     page: 1466 - 1473   2020

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    Web of Science

  42. Voltage Balancing Control Method Using Variable Capacitors with Simple Turn-on Adjusting Function for Multi-Stage FET Bidirectional Converter

    Ishikura Yuki, Hosotani Tatsuya, Noah Mostafa, Imaoka Jun, Yamamoto Masayoshi

    2020 THIRTY-FIFTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2020)     page: 2944 - 2949   2020

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    Web of Science

  43. Energy Management Storage System with a Multi-stage FET Bidirectional Converter

    Ishikura Yuki, Hosotani Tatsuya, Yamamoto Masayoshi

    Journal of the Japan Institute of Power Electronics   Vol. 46 ( 0 ) page: 44 - 50   2020

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    This paper presents an energy management storage system with a multi-stage FET bidirectional converter. The
    proposed system is constructed by a bidirectional converter using series connected FETs, and it realizes highly energy management that maximizes battery performance. By calculating the power loss using the converter performance index FOM (Figure of merit), it is shown that the proposed configuration can be possible to reduce the power loss 70% compared to the conventional configuration. In the proposed system, using a power control method that reduces the charging current, the battery charging losses can be reduced 60%. The analysis results show that the proposed system can achieve a charging energy efficiency of 96.9%, and reduce the yearly CO2 emission of 33%.

    DOI: 10.5416/jipe.46.44

    CiNii Research

  44. Dielectric Characteristics Analysis of Aluminum Electrolytic Capacitors Based on Linear Response Function Reviewed International journal

    Mukaiyama Daisaku, Yamamoto Masayoshi

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   Vol. 166 ( 16 ) page: E554 - E563   2019.12

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  45. Modeling, Magnetic Design, Simulation Methods, and Experimental Evaluation of Various Powder Cores Used in Power Converters Considering Their DC Superimposition Characteristics Reviewed International journal

    Imaoka Jun, Okamoto Kenkichiro, Shoyama Masahito, Ishikura Yuki, Noah Mostafa, Yamamoto Masayoshi

    IEEE TRANSACTIONS ON POWER ELECTRONICS   Vol. 34 ( 9 ) page: 9033 - 9051   2019.9

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  46. Comprehensive Analysis of Coupled Inductors with Powder Cores Used in Interleaved Converter: Measurement, Modeling, Design Methods, and Experimental Evaluation

    Aoki T., Imaoka J., Yamamoto M., Yoshimoto K.

    Proceedings of the International Conference on Power Electronics and Drive Systems   Vol. 2019-July   2019.7

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    One of the best techniques for downsizing power converters is to use coupled inductors in multiphase circuits. Meanwhile, from a magnetic material perspective, powder core material is well known as an attractive magnetic material with superior features such as high saturation flux density. However, since the relative permeability of power cores depends on the magnetic field intensity, designing coupled inductors is difficult, and the modeling method is not well discussed in the relevant literature. The purpose of this research is to model coupled inductors with powder cores and present a simple magnetic design method. A model of coupled inductors is created by a novel measurement method of the dc superimposition characteristic unique to the coupled inductor of two-phase interleaved circuits. Furthermore, a design method based on a theoretical analysis using a magnetic circuit model had been established. The validity and effectiveness of the proposed methods are confirmed from simulation and experimental tests. This research is helpful in the field of the model-based development of coupled inductors.

    DOI: 10.1109/PEDS44367.2019.8998883

    Scopus

  47. Bidirectional Converter with Balancing Capacitor using Multi-stage FET Driving Technique

    Ishikura Y., Imaoka J., Noah M., Yamamoto M.

    2019 IEEE 3rd International Conference on DC Microgrids, ICDCM 2019     2019.5

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    This paper proposes a bidirectional converter with balancing capacitor using multi-stage FET driving technique. The proposed converter is constructed by implementing series-connected low voltage Si-FETs in multi-stages. The balancing capacitor can average the applied voltage on FETs in the transient state of the switching operation and tackle the voltage unbalance between the series-connected FETs. The proposed driving circuit is using multi-stage FET driving technique and can drive all the series-connected FETs using only one power supply. The effect of the balancing capacitor and the proposed driving technique are clarified and presented using the circuit simulator and the converter equivalent circuit. The proposed topology improves the converter power conversion efficiency. The experimental results show that the proposed driving technique allows the bidirectional converter to achieve a maximum power conversion efficiency of 99.2%.

    DOI: 10.1109/ICDCM45535.2019.9232896

    Scopus

  48. Cooperative Control of Multi-Input Modular DC/DC Converter for Electric Off-Highway Vehicles

    Piao Q., Konoto M., Kakisaka T., Imaoka J., Yamamoto M.

    2019 IEEE 3rd International Conference on DC Microgrids, ICDCM 2019     2019.5

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    This paper proposes a cooperative control used in a power conversion system consists of several energy sources and modular DC/DC converters. The proposed cooperative control method has attractive features of realizing constant dynamic characteristics even when each input voltage fluctuates or in case of the output power of each input voltage source is limited. The proposed cooperative control method has dual control loops with current control as an inner loop and voltage control as the outer loop. In addition, feed-forward control of the input voltage and the compensators for each control loop are implemented to suppress the influence of input voltage fluctuation or power capacity limit on dynamic characteristics. The effectiveness of the proposed control is validated by simulation test.

    DOI: 10.1109/ICDCM45535.2019.9232868

    Scopus

  49. 東海支部における地域貢献活動紹介

    山本 真義

    電気学会誌   Vol. 139 ( 4 ) page: 244 - 244   2019.4

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    Language:Japanese   Publisher:一般社団法人 電気学会  

    <p>はじめに</p><p>電気学会東海支部としては,学術講演会,講習会,見学会,サイエンスセミナーなどの諸行事を開催し,学会活動の一層のオープン化を目指している。今回はそういった地域貢</p>

    DOI: 10.1541/ieejjournal.139.244

    CiNii Research

  50. Introduction: Applications Roadmap of GaN Power Semiconductor Devices

    YAMAMOTO Masayoshi

    The Journal of The Institute of Electrical Engineers of Japan   Vol. 139 ( 2 ) page: 76 - 79   2019.2

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    DOI: 10.1541/ieejjournal.139.76

    CiNii Research

  51. Comprehensive Analysis of Coupled Inductors with Powder Cores Used in Interleaved Converter: Measurement, Modeling, Design Methods, and Experimental Evaluation

    Aoki Tatsuya, Imaoka Jun, Yamamoto Masayoshi, Yoshimoto Kosuke

    2019 IEEE 13TH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND DRIVE SYSTEMS (PEDS)     2019

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  52. Comparative Evaluation of Electrical and Calorimetric Methods to Estimate Core Loss in Powder Cores

    Ishikura Yuki, Imaoka Jun, Noah Mostafa, Yamamoto Masayoshi

    IEEJ Journal of Industry Applications   Vol. 8 ( 3 ) page: 386 - 393   2019

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    <p>The utilization of powder cores for many power electronic applications has drawn a significant amount of attention owing to their attractive magnetic properties. However, because of their low relative permeability characteristics, a precise measurement of the core loss is very difficult to obtain. Imprecise estimation of the core loss may lead to an inaccurate thermal design of power converters. Measuring and calculating the accurate value of the core loss allows the circuit designer to design a more efficient system. This paper discusses the revalidation of electrical measurement by comparing the electrical method with the calorimetric method in powder cores. The calorimetric method is one of the most promising methods to accurately measure the core loss; however, it is time consuming. A difference less than 10% has been reported for the core loss measurement error while comparing the electrical method and the calorimetric method in various conditions. These results indicate that the electrical method using the B-H analyzer is effective for measuring the core losses in some conditions for powder cores. Along with the theoretical discussion, simulation and experimental tests are also conducted.</p>

    DOI: 10.1541/ieejjia.8.386

    Web of Science

    Scopus

    CiNii Research

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

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

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

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  54. Study on the Imbalanced Voltage of Series-connected Active Power Semiconductor Devices in Power Conversion Systems

    Zhang Hongjing, Imaoka Jun, Noah Mostafa, Ishikura Yuki, Yamamoto Masayoshi

    2019 IEEE WORKSHOP ON WIDE BANDGAP POWER DEVICES AND APPLICATIONS IN ASIA (WIPDA ASIA 2     2019

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    Web of Science

  55. Magnetic Design Method for Multi-Material Powder Core Inductor to Improve Efficiency of Bidirectional DC/DC Converter within Wide Load Range

    Imaoka J., Ishikura Y., Ito K., Aoki T., Noah M., Yamamoto M.

    2019 10TH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND ECCE ASIA (ICPE 2019 - ECCE ASIA)     2019

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    Web of Science

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

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

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

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  57. Bidirectional Converter with Balancing Capacitor using Multi-stage FET Driving Technique

    Ishikura Yiki, Imaoka Jun, Noah Mostafa, Yamamoto Masayoshi

    2019 IEEE THIRD INTERNATIONAL CONFERENCE ON DC MICROGRIDS (ICDCM)     2019

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    Web of Science

  58. Cooperative Control of Multi-Input Modular DC/DC Converter for Electric Off-Highway Vehicles

    Piao Qingyun, Konoto Masaaki, Kakisaka Tasuku, Imaoka Jun, Yamamoto Masayoshi

    2019 IEEE THIRD INTERNATIONAL CONFERENCE ON DC MICROGRIDS (ICDCM)     2019

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    Web of Science

  59. Common Mode Conductive Noise Cancellation for Multiphase Converter Using Auxiliary Winding

    Sasaki Mamoru, Imaoka Jun, Yamamoto Masayoshi, Nakano Akira, Fuse Koji

    2019 IEEE THIRD INTERNATIONAL CONFERENCE ON DC MICROGRIDS (ICDCM)     2019

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    Web of Science

  60. Core Loss Evaluation in Powder Cores: A Comparative Comparison between Electrical and Calorimetric Methods

    Ishikura Y., Imaoka J., Noah M., Yamamoto M.

    2018 International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018     page: 1087 - 1094   2018.10

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    Utilizing powder cores in many power electronics applications have gained interest due to the attractive magnetic properties of powder core materials. For instance, powder cores have soft saturation characteristics and high saturation flux density compared to gapped ferrites. However, due to their low relative-permeability and the low loss characteristics, a precise measurement of the core losses is very difficult to be obtained. One of the common approaches to measure core losses is by measuring the electrical signals of the winding terminals, we hereafter refer it as electrical methods. Another alternative approach is calorimetric methods, which rely on measuring the core temperature rise. Nonetheless, these methods may have huge measurement error in case of powder cores. This paper evaluates the accuracy of measuring core losses in powder cores, and a comparison between the electrical and calorimetrical methods is presented. Along with the theoretical discussion, simulation and experimental tests are conducted.

    DOI: 10.23919/IPEC.2018.8508012

    Scopus

  61. Effect of inductor parasitic resistances on the voltage gain of high step-up DC-DC converters for electric vehicle applications

    Martinez Wilmer, Cortes Camilo, Yamamoto Masayoshi, Imaoka Jun

    IET POWER ELECTRONICS   Vol. 11 ( 10 ) page: 1628 - 1639   2018.8

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  62. Review of Current Balance Mechanism in Multiphase LLC Resonant Converters

    Noah M., Imaoka J., Ishikura Y., Umetani K., Yamamoto M.

    IEEE International Symposium on Industrial Electronics   Vol. 2018-June   page: 1030 - 1036   2018.8

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    In multi-phase power conversion circuits, achieving an equalized current sharing between the paralleled modules is a challenge. Especially, in the LLC resonant converter topology, where the voltage gain is very sensitive to a minor change in the resonant tank parameters. In practical applications, the resonant tank parameters are never exactly identical among the phases, leading to unbalanced current sharing between the paralleled modules. This paper reviews the state of the art of current balance mechanisms proposed previously in the literature and revisits a newly proposed method to improve the current balance, which relies on a single balancing transformer connected in series with the paralleled resonant tanks. A comparison between the proposed method and connecting the three transformers in star is conducted. While evaluating the current balancing methods, the following sources of unbalance have been considered: a) resonant and magnetizing inductances b) resonant capacitors. c) on-resistances of the switching devices. d) propagation delay of the gate drivers.

    DOI: 10.1109/ISIE.2018.8433827

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  63. Oscillation analysis and current peak reduction in paralleled SiC MOSFETs

    Nanamori Kimihiro, Sugihara Yusuke, Yamamoto Masayoshi

    IET CIRCUITS DEVICES & SYSTEMS   Vol. 12 ( 4 )   2018.7

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    DOI: 10.1049/iet-cds.2017.0255

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  64. Ankle–brachial pressure index as a predictor of the 2-year outcome after transcatheter aortic valve replacement: data from the Japanese OCEAN-TAVI Registry

    Yamawaki M., Araki M., Ito T., Honda Y., Tokuda T., Ito Y., Ueno H., Mizutani K., Tabata M., Higashimori A., Tada N., Takagi K., Yamanaka F., Naganuma T., Watanabe Y., Yamamoto M., Shirai S., Hayashida K.

    Heart and Vessels   Vol. 33 ( 6 ) page: 640 - 650   2018.6

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    Peripheral artery disease plays a pivotal role for access site selection in transcatheter aortic valve replacement (TAVR). Abnormal ankle–brachial index (ABI) is a generalized mortality marker in many cardiovascular scenarios. However, the long-term outcomes in high-risk TAVR populations remain unclear. We investigated the association between low ABI and 2-year outcome after TAVR. Of 1613 patients enrolled in the OCEAN-TAVI registry, 1458 (90.4%) who underwent ABI before TAVR were divided into groups: patients with (1) ABI ≥ 0.9 in both legs and (2) ABI < 0.9 in either leg. Primary endpoint was all-cause death within 2 years. ABI < 0.9 was noted in 304 patients (20.8%). ABI < 0.9-group had more frequent and severe comorbidities. Primary endpoint in ABI < 0.9-group was significantly higher than that in ABI ≥ 0.9-group (15.8 vs. 8.7%, p < 0.001). This trend continued in the transfemoral (TF)-approach (14.9 vs. 7.5%, p < 0.001), but not in the alternative approach (17.2 vs. 15.8%, p = 0.815). Within 30 days, ABI < 0.9-group had a higher cardiac death rate (3.1 vs. 1.0%, p = 0.033), whereas between 31 days and 2 years, non-cardiovascular death was more frequently observed (9.2 vs. 5.1%, p = 0.003). In ABI < 0.9-group, in-hospital vascular complications (11.9 vs. 4.9%, p < 0.001) and acute kidney injury (10.8 vs, 5.7%, p = 0.009) were more frequently found when using the transfemoral-approach. In multivariate analysis, ABI < 0.9 was an independent predictor of 2-year mortality (adjusted hazard ratio 1.495, 95% CI 1.007–2.220, p = 0.046). Pre-procedure ABI < 0.9 is a useful prognostic marker for all-cause mortality, even in high-risk TAVR populations.

    DOI: 10.1007/s00380-017-1096-y

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  65. A Current Sharing Method Utilizing Single Balancing Transformer for a Multiphase LLC Resonant Converter With Integrated Magnetics Reviewed International coauthorship International journal

    Noah Mostafa, Endo Shun, Ishibashi Hiroki, Nanamori Kimihiro, Imaoka Jun, Umetani Kazuhiro, Yamamoto Masayoshi

    IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS   Vol. 6 ( 2 ) page: 977 - 992   2018.6

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    Integrated magnetics is applied to replace the three-discrete transformers by a single core transformer in a three-phase LLC resonant converter. The magnetic circuit of the integrated transformer is analyzed to derive coupling factors between the phases; these coupling factors are intentionally minimized to realize the magnetic behavior of the three-discrete transformers, with the benefit of eliminating the dead space between them. However, in a practical design, the transformer parameters in a multiphase LLC resonant converter are never exactly identical among the phases, leading to unbalanced current sharing between the paralleled modules. In this regard, a current balancing method is proposed in this paper. The proposed method can improve the current sharing between the paralleled phases relying on a single balancing transformer, and its theory is based on Ampere's law, by forcing the sum of the three resonant currents to zero. Theoretically, if an ideal balancing transformer has been utilized, it would impose the same effect of connecting the integrated transformer in a solid star connection. However, as the core permeability of the balancing transformer is finite, the unbalanced current cannot be completely suppressed. Nonetheless, utilizing a single balancing transformer has an advantage over the star connection, as it keeps the interleaving structure simple which allows for traditional phase-shedding techniques, and it can be a solution for the other multiphase topologies where realizing a star connection is not feasible. Along with the theoretical discussion, simulation and experimental results are also presented to evaluate the proposed method considering various sources of the unbalance such as a mismatch in: 1) resonant and magnetizing inductances; 2) resonant capacitors; 3) transistor on-resistances of the MOSFETS; and 4) propagation delay of the gate drivers.

    DOI: 10.1109/JESTPE.2017.2777508

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  66. A Magnetic Design Method Considering DC-Biased Magnetization for Integrated Magnetic Components Used in Multiphase Boost Converters Reviewed International coauthorship International journal

    Imaoka Jun, Okamoto Kenkichiro, Kimura Shota, Noah Mostafa, Martinez Wilmar, Yamamoto Masayoshi, Shoyama Masahito

    IEEE TRANSACTIONS ON POWER ELECTRONICS   Vol. 33 ( 4 ) page: 3346 - 3362   2018.4

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    High power density and high efficiency in dc/dc converters are required in various applications such as the automotive application. Interleaved multiphase circuits with integrated magnetic components can fulfill these requirements because passive components occupying significant space in power converters can be downsized without high-switching frequency driving of power devices. However, dc-biased magnetization is a drawback of integrated magnetic components because of unbalanced inductor average currents. This imbalance arises from the tolerance among the phase components. To overcome this problem, inductor average current control is implemented in interleaved multiphase dc/dc converters. Nevertheless, the imbalance cannot be completely eliminated because the current sensors inserted into each phase have gain errors. The purpose of this paper is to present a magnetic design method to improve the immunity to unbalanced currents. A comprehensive analysis is carried out with two main objectives: to prevent magnetic saturation, which may arise due to the current unbalance and to downsize the magnetic components by selecting the optimal coupling coefficient taking into consideration the maximum permissible percentage of unbalanced currents. Simulation case studies are presented to support the analysis. Finally, a 1-kW prototype of the interleaved boost converter is built to validate the accuracy of the design method.

    DOI: 10.1109/TPEL.2017.2707385

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  67. Lagrangian dynamics model and practical implementation of an integrated transformer in multi-phase LLC resonant converter

    Noah Mostafa, Umetani Kazuhiro, Imaoka Jun, Yamamoto Masayoshi

    IET POWER ELECTRONICS   Vol. 11 ( 2 ) page: 339 - 347   2018.2

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    DOI: 10.1049/iet-pel.2017.0485

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  68. Winding orientation method to minimise the secondary leakage of a gapped transformer utilised in LLC resonant converter

    Noah M., Umetani K., Yamamoto M., Imaoka J.

    ELECTRONICS LETTERS   Vol. 54 ( 3 ) page: 157 - 159   2018.2

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  69. A Novel Transformer Structure Used in a 1.4 MHz LLC Resonant Converter with GaNFETs

    Ou Tengfei, Noah Mostafa, Morita Koichi, Tsuruya Mamoru, Namiki Seiji, Imaoka Jun, Yamamoto Masayoshi

    2018 IEEE INTERNATIONAL POWER ELECTRONICS AND APPLICATION CONFERENCE AND EXPOSITION (PEAC)     page: 1562 - 1566   2018

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  70. Core Loss Evaluation in Powder Cores: A Comparative Comparison between Electrical and Calorimetric Methods

    Ishikura Yuki, Imaoka Jun, Noah Mostafa, Yamamoto Masayoshi

    2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA)     page: 1087 - 1094   2018

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  71. Experimental Evaluation of Inverter System Consisting of 4-parallel GaN Devices Unit

    Ohnuma Yoshiya, Miyawaki Satoshi, Hattori Fumiya, Yamamoto Masayoshi

    2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA)     page: 2738 - 2742   2018

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  72. Parasitic Inductance Design Considerations to Suppress Gate Voltage Oscillation of Fast Switching Power Semiconductor Devices

    Sugihara Yusuke, Nanamori Kimihiro, Yamamoto Masayoshi, Kanazawa Yasuki

    2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA)     page: 2789 - 2795   2018

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  73. Multiple Exciting Voltage Control for Maximization of Multi-hop Wireless Power Transfer Efficiency

    Sasaki Masato, Yamamoto Masayoshi

    2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA)     page: 3344 - 3348   2018

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  74. Modeling, Magnetic Design, and Simulation Methods Considering DC Superimposition Characteristic of Powder Cores Used in Power Converters

    Imaoka Jun, Okamoto Kenkichiro, Shoyama Masahito, Ishikura Yuki, Noah Mostafa, Yamamoto Masayoshi

    2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA     page: 1095 - 1102   2018

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  75. Magnetic Design and Experimental Evaluation of a Commercially Available Single Integrated Transformer in Three-Phase LLC Resonant Converter

    Noah Mostafa, Kimura Shota, Imaoka Jun, Martinez Wilmar, Endo Shun, Yamamoto Masayoshi, Umetani Kazuhiro

    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS   Vol. 54 ( 6 ) page: 6190 - 6204   2018

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    DOI: 10.1109/TIA.2018.2856631

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  76. Fundamental Experiment of 3-phase Electric Resonant Coupling Wireless Power Transfer

    Hattori Fumiya, Imaoka Jun, Yamamoto Masayoshi, Masuda Mitsuru

    2018 7TH INTERNATIONAL CONFERENCE ON RENEWABLE ENERGY RESEARCH AND APPLICATIONS (ICRERA)     page: 1417 - 1422   2018

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  77. Review of Current Balance Mechanism in Multiphase LLC Resonant Converters

    Noah Mostafa, Imaoka Jun, Ishikura Yuki, Umetani Kazuhiro, Yamamoto Masayoshi

    2018 IEEE 27TH INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE)     page: 1030 - 1036   2018

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  78. Proposal for the New Control Method Having High Responsiveness and Robustness for the Boost-Type DC-DC Converter

    Kawakami Taichi, Harada Toshikazu, Yamamoto Masayoshi, Umetani Kazuhiro

    IEEJ Transactions on Electronics, Information and Systems   Vol. 138 ( 4 ) page: 395 - 404   2018

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    <p>This paper proposes a novel control method to improve the responsiveness and the robustness of the boost DC-DC converter. The proposed control method is a feedback control incorporating a minor control that works to balance the input and output power. Experiment was carried out to verify the responsiveness and the robustness of the proposed control in comparison with the conventional voltage-mode and current-mode control. As a result, the proposed method revealed both of the fast response and the robust output voltage regulation against the load change.</p>

    DOI: 10.1541/ieejeiss.138.395

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  79. Bidirectional Converter Using Multistage FET Driving technique with voltage balance function

    Ishikura Yuki, Hosotani Tatsuya, Yamamoto Masayoshi

    Journal of the Japan Institute of Power Electronics   Vol. 44 ( 0 ) page: 128 - 134   2018

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    This paper presents a bidirectional convert using by multistage FET driving technique with voltage balance function. The voltage balance function can reduce influence of the voltage unbalance phenomenon which drain voltage fluctuation depending on output current. The voltage unbalance phenomenon is clarified by using an equivalent circuit of FETs connected in series. The necessity of voltage balance function is discussed, and verified in experiment. The experimental results have proven that the bidirectional converter by using the driving technique can achieve 98% or more power conversion efficiency from 170 W to 1000 W of power range, and a maximum power conversion efficiency of 99.2%.

    DOI: 10.5416/jipe.44.128

    CiNii Research

  80. An mathematical analysis of false turn-on phenomenon of GaN HEMT

    Iwaki T., Sawada T., Yamamoto M.

    2017 IEEE CPMT Symposium Japan, ICSJ 2017   Vol. 2017-January   page: 189 - 190   2017.12

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    GaN-HEMT achieves the reduction in size and weight of power conversion circuits, thanks to its high frequency switching characteristics. However, the switching speed and low threshold voltage may cause a false turn-on phenomenon, which is a fatal effect for the applications. It is urgent issue to tackle and avoid this problem by modifying the circuit conditions. In this letter, the theoretical analysis of a full bridge inverter is developed to figure out the behavior of the gate voltage, which is the keyfactor parameter of false turn-on. Based on the analysis, the circuit conditions which minimize the gate voltage spike are derived.

    DOI: 10.1109/ICSJ.2017.8240113

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  81. An analysis of false turn-on phenomenon of GaN HEMT with parasitic components

    Iwaki T., Ishiwaki S., Sawada T., Yamamoto M.

    INTELEC, International Telecommunications Energy Conference (Proceedings)   Vol. 2017-October   page: 347 - 350   2017.12

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    Wide band gap power semiconductor devices are now replacing the Si-MOSFET or IGBT. GaN-HEMT achieves the reduction in size and weight, thanks to its high frequency switching behavior. However, its high-speed switching characteristics and low threshold voltage may cause a false turn-on phenomenon, which is a fatal effect for the applications. It is urgent issue to tackle and avoid this problem by modifying the circuit conditions. We described differential equations from simplified equivalent circuit of inverter, and algebraically solved with some assumptions. At the same time, drain voltage equation is also developed. As a result, the gate voltage fluctuation was described as a composite waveform including two LC resonance phenomenon, which occur on gate drive circuit and main power flow.

    DOI: 10.1109/INTLEC.2017.8214160

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  82. Analytical investigation of interleaved DC-DC converter using closed-coupled inductor with phase drive control

    Ebisumoto D., Kimura S., Nanamori K., Noah M., Ishihara M., Imaoka J., Yamamoto M.

    INTELEC, International Telecommunications Energy Conference (Proceedings)   Vol. 2017-October   page: 526 - 529   2017.12

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    Interleaved techniques and magnetic integration in a boost converter have gained attention in electric powertrains system for electric, hybrid and fuel cell vehicles in order to achieve high power density or to improve power conversion efficiency. Furthermore, the proposed multi-phase boost converter is equipped with a phase drive control to improve the efficiency at all load ranges. Furthermore, a design method of a coupled-inductor for an interleaved boost converter with phase drive control is also proposed. However, the interleaved DC-DC converter using coupled method with phase drive control has many problems. In this paper, this problem of interleaved DC-DC converter using coupled inductor with phase drive control (PDC) is analyzed. In addition, defensive method of this method.

    DOI: 10.1109/INTLEC.2017.8214190

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  83. Total volume evaluation of high-power density non-isolated DC-DC converters with integrated magnetics for electric vehicles Reviewed International coauthorship International journal

    Martinez Wilmar, Cortes Camilo, Yamamoto Masayoshi, Imaoka Jun, Umetani Kazuhiro

    IET POWER ELECTRONICS   Vol. 10 ( 14 ) page: 2010 - 2020   2017.11

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    One of the main problems in electric vehicles is the volume of their electrical systems because their bulky components carry additional mass and high cost to the total system. On this topic, interleaving-phases and magnetic coupling techniques have been reported as effective methods for increasing the power density of the DC-DC converters that work between the storage unit and the motor inverter. In that sense, a volume assessment of these topologies would provide a better understanding of the problems to be faced when an electric power train is designed. In this paper, a volume modelling methodology is introduced with the purpose of comparing four different DC-DC converters: Single-Phase Boost, Two-Phase Interleaved with non-coupled inductors, Loosely Coupled Inductor (LCI), and Integrated Winding Coupled Inductor (IWCI). The analysis considers the volume of magnetic components, power devices (conventional and next-generation), cooling devices and capacitors. The methodology can be used as a part of an optimization procedure to minimize the volume of DC-DC converters. Conclusively, LCI and IWCI were found effective to miniaturize power converters with a power density of 8.4 W/cc and 9.66 W/cc, respectively. Moreover, a maximum efficiency of 98.04% and 97.61% was obtained for a 1kW LCI and IWCI prototypes, respectively.

    DOI: 10.1049/iet-pel.2017.0157

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  84. An investigation into a slight-variation of the transformer effective permeability in LLC resonant converter

    Noah M., Endo S., Kimura S., Yamamoto M., Imaoka J., Umetani K., Hiraki E.

    2017 19th European Conference on Power Electronics and Applications, EPE 2017 ECCE Europe   Vol. 2017-January   2017.11

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    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.

    DOI: 10.23919/EPE17ECCEEurope.2017.8099301

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  85. A Lagrangian dynamics model of integrated transformer incorporated in a multi-phase LLC resonant converter

    Noah M., Umetani K., Endo S., Ishibashi H., Imaoka J., Yamamoto M.

    2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017   Vol. 2017-January   page: 3781 - 3787   2017.11

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    In conventional arrangements of three-phase LLC converters, there are at least three magnetic components that occupy a considerable volume and mass of the power converter. Although, the three-phase LLC topology has many advantages over the single-phase one, circuit designers tend to select the singlephase topology because it has a minimal number of magnetic components. In this paper, with the purpose of promoting the industrial applications of the three-phase topology, Lagrangian dynamics is applied to theoretically prove that it is possible to replace the three-discrete transformers by a single integrated transformer. The Lagrangian dynamics theory allowed us to derive a physically motivated model for the integrated transformer, in which each component of the integrated transformer has its own Lagrangian parameter. The remarkable result to emerge from the Lagrangian model is that in a symmetrical design, there is no interphase coupling; this is regardless of the value of the coupling coefficient between the phases. This means that there is no return path for the three ac fluxes, and as a result the magnetic components can be downsized. Therefore, the major advantages of using integrated magnetics in the LLC converter can be concluded as: cost-reduction, reduced weight, and realizing higher power density. Along with the theoretical discussion, experimental validation is provided utilizing a 500W - 390V/12V - 200kHz prototype.

    DOI: 10.1109/ECCE.2017.8096668

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  86. Analytical investigation on design instruction to avoid oscillatory false triggering of fast switching SiC-MOSFETs

    Sugihara Y., Nanamori K., Ishiwaki S., Hayashi Y., Aikawa K., Umetani K., Hiraki E., Yamamoto M.

    2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017   Vol. 2017-January   page: 5113 - 5118   2017.11

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    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.

    DOI: 10.1109/ECCE.2017.8096861

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  87. Analysis of false turn-on phenomenon of GaN HEMT with parasitic inductances for propose novel design method focusing on peak gate voltage

    Ishiwaki S., Iwaki T., Sugihara Y., Nanamori K., Yamamoto M.

    2017 IEEE Energy Conversion Congress and Exposition, ECCE 2017   Vol. 2017-January   page: 1395 - 1401   2017.11

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    GaN HEMT is generally characterized as fast switching and expected to achieve a power converter with high efficiency and high power density as a next-generation power semiconductor. However, the fast switching generates large switching noise, causing gate voltage fluctuation. Therefore, GaN HEMT can suffer from false triggering such as a false turn-on phenomenon due to its own low threshold voltage. The phenomenon is problematic especially for practical applications such as a half-bridge circuit. In order to elucidate this phenomenon, we derived the equation expressing gate voltage fluctuation. As a result, the gate voltage fluctuation was described as a composite waveform including two resonance frequencies. Additionally, the appropriateness of the analysis result was supported by comparing theoretical peak gate voltage of the simulation and experimental results. On the other hand analytical results indicated likelihood that balancing factors included in an analytical expression suppress false turn-on phenomenon. Although analytical treatment elucidated gate voltage fluctuation comprehensively, theoretical equation is complicated as design guideline to avoid the false turnon phenomenon. Therefore, this paper analyzed the gate voltage fluctuation mathematically based on L'Hopital's Rule and derived the minimum condition of the peak gate voltage. As a result, mathematical treatment proposes a design method focusing on a peak gate voltage that can achieve the safe operation of a halfbridge circuit.

    DOI: 10.1109/ECCE.2017.8095953

    Scopus

  88. Mathematical analysis of GaN high electron mobility transistor false turn-on phenomenon

    Iwaki T., Ishiwaki S., Sawada T., Yamamoto M.

    ELECTRONICS LETTERS   Vol. 53 ( 19 )   2017.9

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    DOI: 10.1049/el.2017.2225

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  89. A Lagrangian Dynamics Model of Integrated Transformer Incorporated in a Multi-phase LLC Resonant Converter

    Noah Mostafa, Umetani Kazuhiro, Endo Shun, Ishibashi Hiraki, Imaoka Jun, Yamamoto Masayoshi

    2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)     page: 3781 - 3787   2017

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    Web of Science

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

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

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

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  91. Analytical Investigation of Interleaved DC-DC Converter using Closed-Coupled Inductor with Phase Drive Control

    Ebisumoto Daigoro, Kimura Shota, Nanamori Kimihiro, Noah Mostafa, Ishihara Masataka, Imaoka Jun, Yamamoto Masayoshi

    2017 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC)     page: 526 - 529   2017

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  92. Analysis of False Turn-On Phenomenon of GaN HEMT with Parasitic Inductances for Propose Novel Design Method Focusing on Peak Gate Voltage

    Ishiwaki Seiya, Iwaki Toshihiro, Sugihara Yusuke, Nanamori Kimihiro, Yamamoto Masayoshi

    2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)     page: 1395 - 1401   2017

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  93. An Mathematical Analysis of False Turn-On Phenomenon of GaN HEMT

    Iwaki Toshihiro, Sawada Takashi, Yamamoto Masayoshi

    2017 IEEE CPMT SYMPOSIUM JAPAN (ICSJ)     page: 189 - 190   2017

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    Web of Science

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

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

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

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  95. An Analysis of False Turn-On Phenomenon of GaN HEMT with Parasitic Components

    Iwaki Toshihiro, Ishiwaki Seiya, Sawada Takashi, Yamamoto Masayoshi

    2017 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC)     page: 347 - 350   2017

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  96. Allowable Power Analysis and Comparison of High Power Density DC-DC Converters with Integrated Magnetic Components

    Kimura Shota, Nanamori Kimihiro, Kawakami Taichi, Imaoka Jun, Yamamoto Masayoshi

    IEEJ Journal of Industry Applications   Vol. 6 ( 6 ) page: 463 - 472   2017

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    <p>Interleaved dc-dc converters with integrated magnetic components are popular as converters capable to achieve high efficiency with less of volume and mass. There are three methods for integrated magnetic components: loosely-coupled inductors, closed-coupled inductors and integrated-winding-coupled inductors. This paper presents a method to calculate the allowable power in various circuit topologies. It is useful for measuring the allowable power without magnetic saturation of an inductor based on its size. Following the analysis of allowable power for each coupled inductor, the allowable power of the integrated magnetic components is compared to that of the conventional interleaved converter. This comparison is realized under the same conditions. As a result, the interleaved converter with loosely-coupled and integrated winding coupled inductors were found to be effective for the downsizing of the magnetic components under continuous conduction mode operation. On the other hand, the interleaved converter with close-coupled inductors is effective for the downsizing of the magnetic components under critical conduction mode operation. This comparative data is discussed from both theoretical and experimental points of view.</p>

    DOI: 10.1541/ieejjia.6.463

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  97. A Novel LLC Resonant DC-DC Converter with Integrated Transformer

    Kimura Shota, Nanamori Kimihiro, Noah Mostafa, Yamamoto Masayoshi

    2017 IEEE INTERNATIONAL TELECOMMUNICATIONS ENERGY CONFERENCE (INTELEC)     page: 506 - 510   2017

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    Authorship:Last author   Language:English  

    Web of Science

  98. Modeling and Design of Interleaved Multi-phase DC-DC Converter with 2-phase Coupled Inductor Cell for High Power Density

    Kimura Shota, Nanamori Kimihiro, Yamamoto Masayoshi

    2017 IEEE 6TH INTERNATIONAL CONFERENCE ON RENEWABLE ENERGY RESEARCH AND APPLICATIONS (ICRERA)     page: 416 - 422   2017

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    Authorship:Last author   Language:English  

    Web of Science

  99. Power Flow Interactive Sharing between Two DC Nanogrids Photovoltaic Local Branch Dynamic System at Island Operation

    Bauomy Maged F., Gamal Haytham, Shaltout Adel A., Noah Mostafa, Yamamoto Masayoshi

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

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    Authorship:Last author   Language:English  

    Web of Science

  100. Magnetic Structure of Close-Coupled Inductors to Improve the Thermal Handling Capability in Interleaved DC-DC Converter

    Chuong Thai Hoang, Kimura Shota, Ebisumoto Daigoro, Noah Mostafa, Ishihara Masataka, Yamamoto Masayoshi, Imaoka Jun, Martinez Wilmar

    2017 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)     page: 205 - 210   2017

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    Language:Japanese  

    Web of Science

  101. Analysis of Self Turn-ON Phenomenon for the Application of Power Semiconductor Devices

    Proceedings of Microelectronics Symposium   Vol. 27 ( 0 ) page: 15 - 16   2017

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    Language:Japanese   Publisher:The Japan Institute of Electronics Packaging  

    DOI: 10.11486/mes.27.0_15

    CiNii Research

  102. Analyzing visitors' characteristics in tourist areas based on mobile phone users' location data

    Yamamoto M.

    Conference Proceedings - 23rd ISSAT International Conference on Reliability and Quality in Design     page: 1 - 5   2017

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    Language:Japanese   Publisher:Conference Proceedings - 23rd ISSAT International Conference on Reliability and Quality in Design  

    In recent years, so-called "big data" have been attracting the attention of companies and researchers. This study aims to identify the number of visitors of each period and their characteristics based on the location data of mobile phone users collected by the mobile phone company. The study sites of this survey are tourist destinations in Ishikawa Prefecture and Toyama city, including Kanazawa city, which became nationally popular after the Hokuriku Shinkansen opened in 2015. The opening of the Hokuriku Shinkansen brought more visitors to many areas. However, it also led to fewer visitors in some areas. The positive effect was remarkable in Kanazawa.

    Scopus

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Books 13

  1. フォルクスワーゲン「ID.3」徹底分解

    山本真義( Role: Joint author)

    日経BP  2022.2 

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    Language:Japanese Book type:Textbook, survey, introduction

  2. パワー半導体SiC/GaNの課題... 高速スイッチングによるサージと 対策回路への研究

    山本真義( Role: Joint author)

    CQ出版株式会社  2022.2 

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    Language:Japanese Book type:Textbook, survey, introduction

  3. 電動車向け次世代パワー半導体の最新動向と今後の予測

    山本真義( Role: Joint author)

    技術情報協会  2022.2 

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    Language:Japanese Book type:Textbook, survey, introduction

  4. 次世代EV/HEV用モータの高出力化と関連材料の開発

    山本真義( Role: Joint author)

    技術情報協会  2022.1 

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    Language:Japanese Book type:Textbook, survey, introduction

  5. 次世代パワー半導体の開発動向と応用展開EV・HEV用モータと、高出力化に向けた関連材料の開発

    山本真義( Role: Joint author)

    技術情報協会  2021.12 

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    Language:Japanese Book type:Textbook, survey, introduction

  6. テクノロジー・ロードマップ 2022-2031 全産業編

    山本真義( Role: Joint author)

    日経BP  2021.11 

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    Language:Japanese

  7. JRCM NEWS

    山本真義( Role: Joint author)

    一般財団法人 金属材料研究開発センター  2021.8 

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    Total pages:6   Responsible for pages:1   Language:Japanese

  8. 次世代ジェット旅客機

    山本真義( Role: Sole author)

    日刊興業新聞  2021.5 

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    Total pages:28   Responsible for pages:1   Language:Japanese

  9. 自動車電動化の潮流

    山本真義( Role: Sole author)

    日刊工業新聞  2021.2 

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    Total pages:36   Responsible for pages:1   Language:Japanese

  10. 次世代パワー半導体の開発と空飛ぶクルマへの適用

    山本真義( Role: Sole author)

    空飛ぶクルマ  2020.10 

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    Total pages:350   Responsible for pages:20   Language:Japanese

  11. xEV における SiC/GaN 応用パワーエレクトロニクスの EMC 対策技術

    山本真義( Role: Sole author)

    月刊 車載テクノロジー  2020.9 

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    Total pages:500   Responsible for pages:6   Language:Japanese Book type:Textbook, survey, introduction

  12. 超高速GaNパワー半導体応用におけるノイズ発生 メカニズムと高速スイッチングに起因するノイズの効果的な抑制法

    山本真義( Role: Sole author)

    工業材料  2020.9 

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    Total pages:450   Responsible for pages:7   Language:Japanese Book type:Textbook, survey, introduction

  13. 次世代自動車用パワー半導体と周辺機器・部材の分解解説と技術動向

    山本真義( Role: Sole author)

    クリーンテクノロジー  2020.9 

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    Total pages:450   Responsible for pages:7   Book type:Textbook, survey, introduction

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Presentations 47

  1. 日米欧中の電気自動車(EV)戦略と2030年の電気自動車予想像 Invited

    山本真義

    弁理士会講演会  2022.2.19  弁理士会

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  2. 航空機電動化に向けた高電力密度インバータ設計手法の各リスト実証 Invited

    山本真義

    知の拠点あいち公開セミナー  2022.2.17  知の拠点重点研究プロジェクト統括部

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  3. 2030年の次世代自動車像とそれを支える電動化テクノロジー

    山本真義

    第4回未来のクルマTechnology  2022.2.16  株式会社JTBコミュニケーションデザイン

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  4. 宏光MINI EV(中国・五菱)の分解解説ならびに2030年の電気自動車予想像と広島県自動車関連企業の執るべき戦略 Invited

    山本真義

    広島市ものづくり支援化  2022.2.1  広島市 経済観光局産業振興部

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  5. 日米欧中の電気自動車(EV)戦略と各自動車メーカが求めるEV用材料・素材・パワーエレクトロニクス応用技術最前線 Invited

    山本真義

    山口県産業戦略部オンラインセミナー  2022.1.20  山口県 産業戦略部

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    Event date: 2022.1

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  6. 宏光MINI EVセミナー

    山本真義

    宏光MINI EVセミナー  2021.12.14  一般社団法人日本能率協会

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    Event date: 2021.12

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

    Venue:愛知県名古屋市   Country:Japan  

  7. 次世代自動車2030年ロードマップとそれを支える次世代パワー半導体実装基板技術 Invited

    山本真義

    IMSIオープンフォーラム2021  2021.12.9  一般社団法人電子実装工学研究所

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    Event date: 2021.12

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  8. Next Generation Electric Vehicle in 2030 and Module Packaging and Bonding of Next Generation Power Semiconductor Device for Its Automotive Applications Invited International conference

    2021.12.9 

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    Event date: 2021.12

    Language:English   Presentation type:Oral presentation (keynote)  

    Country:Japan  

  9. 車載用パワーエレクトロニクス技術最新動向とSiC/GaN適用の事例と可能性に関する議論 Invited

    山本真義

    NEDIAパワーエレクトロニクス講座  2021.12.3  財団法人 日本電子デバイス産業協会

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    Event date: 2021.12

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  10. 宏光MINI EVセミナー

    山本真義

    宏光MINI EVセミナー  2021.11.30  一般社団法人日本能率協会

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    Event date: 2021.11

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

    Venue:愛知県名古屋市   Country:Japan  

  11. 主要国における電気自動車の開発動向と我が国が執るべき カーボンニュートラルに向けた電気自動車の市場戦略 Invited

    山本真義

    パワーエレクトロニクス学会  2021.11.20  パワーエレクトロニクス学会

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    Event date: 2021.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  12. 電動車・パワコン・家電民生機器におけるECM対策技術最前線と各応用パワーエレクトロニクス機器分解解説 〜テスラ・モデル3、ジャガー・I-Pace、ポルシェ・タイカン、ファーウェイ製パワコンを中心に〜 Invited

    山本真義

    テクノフェア  2021.11.15  北川工業

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    Event date: 2021.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  13. 日米欧中の電気自動車(EV)戦略と2030年の電気自動車予想像 Invited

    山本真義

    日本弁理士会講演会  2021.11.12  日本弁理士会

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    Event date: 2021.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  14. EV用パワーエレクトロニクス機器の最新技術・市場動向と次世代EVに求められるパワエレ実装技術 Invited

    山本真義

    福岡大学半導体実装研究所講演会  2021.11.11  福岡大学

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    Event date: 2021.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:福岡県福岡市   Country:Japan  

  15. SiC/GaN Hybrid Soft Switching Inverter for Electric Vehicle Applications International conference

    2021.11.6 

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    Event date: 2021.11

    Language:English   Presentation type:Oral presentation (keynote)  

    Country:Japan  

  16. EV用車載パワーエレクトロニクスシステム最新動向と次世代EVに求められるパワエレ実装技術 Invited

    山本真義

    電子機器のトータルソリューション展  2021.10.28  日本貿易振興機構

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    Event date: 2021.10

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:東京ビッグサイト   Country:Japan  

  17. 日米欧中の電気自動車(EV戦略と各自動車メーカのEV用パワーエレクトロニクス応用技術最前線 Invited

    山本真義

    日本弁理士会講演会  2021.10.21  日本弁理士会講演会

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    Event date: 2021.10

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  18. 世界標準化される電気自動車用パワーエレクトロニクスの技術動向と車載用磁性材料へ の期待に関する講演)

    山本真義

    日本ボンド磁性材料協会(JABM)講演会  2021.9.17  日本ボンド磁性材料協会

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    Event date: 2021.9

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  19. EV用車載パワーエレクトロニクスシステム最新動向と次世代EVに求められるパワエレ実装技術 Invited

    山本真義

    カーエレクトロニクス研究会  2021.9.15  エレクトロニクス実装学会 

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    Event date: 2021.9

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  20. 日米欧中のEV用パワー半導体戦略と各自動車メーカの EV用パワーエレクトロニクス応用技術最前線 Invited

    山本真義

    NE先端テクノロジーフォーラム  2021.9.10  日経エレクトロニクス

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    Event date: 2021.9

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  21. パワーコントロールユニット(PCU)における高出力密度を実現する各要素技術と動向 Invited

    山本真義

    産業応用部門大会シンポジウムセッション講演  2021.8.27  電気学会

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    Event date: 2021.8

    Language:Japanese   Presentation type:Oral presentation (keynote)  

    Venue:オンライン   Country:Japan  

  22. 超高速GaNパワー半導体応用におけるノイズ発生メカニズムと 高速スイッチングに起因するノイズの効果的な抑制法 Invited

    山本真義

    応用物理学会 先進パワー半導体分科会  2021.7.30  応用物理学会

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    Event date: 2021.7

    Language:Japanese  

    Venue:名古屋大学   Country:Japan  

  23. 次世代自動車におけるパワーエレクトロニクス機器の1kV化技術動向とそこに求められるワイドバンドギャップパワー半導体応用技術

    山本真義

    ワイドバンドギャップ学会講演会  2021.7.16  ワイドギャップ半導体学会研究会

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    Event date: 2021.7

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  24. 次世代自動車に要求されるSiC/GaNパワーデバイス実装・接合技術と欧米メーカ(テスラ・ジャガー等)のインバータ実装技術紹介 Invited

    山本真義

    日本溶接協会はんだ・微細接合部会シンポジウム  2021.7.5  日本溶接協会

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    Event date: 2021.7

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  25. I-Pace(ジャガー)用インバータの概要と実装手法

    山本真義

    テクノフロンティアセミナー  2021.7.1  一般社団法人日本能率協会

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    Event date: 2021.7

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  26. 北米・欧州・日本の各EV分解から読み解くパワー半導体とそのモジュール・システム 技術最新動向とパワー半導体応用設計思想 Invited

    山本真義

    パワーデバイス用シリコン および関連半導体材料に関する研究会  2021.6.24  一般財団法人ファインセラミックスセンター

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    Event date: 2021.6

    Language:Japanese   Presentation type:Oral presentation (keynote)  

    Venue:オンライン  

  27. 3 I-PACE(ジャガー)・モデル3(テスラ)のインバータ分解から読み解く 車載用熱対策技術最前線とその技術動向 Invited

    山本真義

    テクノフロンティアセミナー  2021.6.10  一般社団法人日本能率協会

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    Event date: 2021.6 - 2021.7

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  28. 各自動車メーカ最新モデル分解から読み解く車載用パワーエレクトロニクス技術 最前線 ~I-PACE(ジャガー)・モデル3(テスラ)・MIRAI(トヨタ)~ Invited

    山本真義

    テクノフロンティアセミナー  2021.6.18  一般社団法人日本能率協会 

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    Event date: 2021.6 - 2021.7

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  29. モデル3(テスラ)用SiCバッテリ充電器における 最新ノイズ対策技術とSiC/GaN時代のノイズ対策技術動向 Invited

    山本真義

    テクノフロンティアセミナー  2021.7.7  一般社団法人日本能率協会

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    Event date: 2021.6 - 2021.7

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  30. 電気自動車向けパワーエレクトロニクス機器の各国における研究開発状況と今後の技術動向 Invited International coauthorship International conference

    山本真義

    日本電気学会:岩崎コンファレンス  2021.5.20  日本電気学会

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    Event date: 2021.5

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  31. EVにおけるPCU及びパワーモジュールの実装・組立技術の開発動向

    山本真義

    ジャパンマーケティングサーベイ  2021.3.30  ジャパンマーケティングサーベイ

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    Event date: 2021.3

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

    Venue:オンライン   Country:Japan  

  32. 名古屋大学におけるGan半導体による電力変換等の研究について

    山本真義

    電源部品事業委員会 JEITA  2021.3.23  電子情報技術産業協会

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    Event date: 2021.3

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

    Venue:オンライン   Country:Japan  

  33. MHzワイヤレス給電を実現する高周波パワー半導体スイッチング技術とその応用事例

    山本真義

    WPT研究会  2021.3.22  WPTシステム研究会

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    Event date: 2021.3

    Presentation type:Symposium, workshop panel (nominated)  

    Venue:オンライン   Country:Japan  

  34. 先進モビリティとパワーエレクトロ二クス技術の進化 Invited

    山本真義

    応用物理学会春季学術講演会  2021.3.17  応用物理学会

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  35. 航空機電動化に向けた高電力密度インバータ設計手法の確立と実証

    山本真義

    知の拠点公開セミナー  2021.3.15  知の拠点あいち

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    Event date: 2021.3

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

    Venue:愛知県長久手市 知の拠点あいち   Country:Japan  

  36. Teslaモデル3分解から読み解く車載応用における技術トレンド Invited

    山本真義

    自動車問題研究会   2021.2.16  自動車問題研究会

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    Event date: 2021.2

    Language:Japanese   Presentation type:Symposium, workshop panel (nominated)  

    Venue:愛知県名古屋市 フォーイン2階多目的ホール   Country:Japan  

  37. 電動車両技術の最新動向

    山本真義

    自動車技術会シンポジウム  2021.2.12  自動車技術会電気動力技術部門委員会

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    Event date: 2021.2

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  38. 次世代パワーエレクトロニクスを革新する高周波・大容量対応パワーマグネティックス応用技術 〜次世代自動車用磁気部品応用技術を例に〜

    山本真義

    マグネティックスによるパワーエレクトロニクスの革新と協創  2021.1.20  電気学会マグネティックス技術委員会

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    Event date: 2021.1

    Language:Japanese   Presentation type:Symposium, workshop panel (nominated)  

    Venue:オンライン   Country:Japan  

  39. 次世代パワー半導体が切り開くモビリティ・インフラ用電力機器の将来と市場可能性

    山本真義

    オンライン  2020.12.18  中部電力

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    Event date: 2020.12

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

    Venue:オンライン   Country:Japan  

  40. 次世代バワー半導体の開発と空飛ぶクルマへの適用

    山本真義

    テクノフロンティアセミナー  2020.12.3  産業能率協会

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    Event date: 2020.12

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

    Venue:オンライン   Country:Japan  

  41. パワエレ技術の最新動向

    山本真義

    愛知県モノづくり技術者のための パワエレセミナー  2020.12.1 

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    Event date: 2020.12

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

    Venue:オンライン   Country:Japan  

  42. 自動車におけるパワーエレクトロ二クス技術が果たす役割と展望 Invited

    山本真義

    応用物理学会  2020.11.28  応用物理学会

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    Event date: 2020.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン   Country:Japan  

  43. テスラ・モデル3の分解から読み解くテスラモーターズ社が考えるパワー半導体応用戦略とそこから予測する次世代自動車像

    山本真義

    電動車両のPCUの高性能化に関する共同研究委員会  2020.11.13  電動車両のPCUの高性能化に関する共同研究委員会

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    Event date: 2020.11

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

    Venue:オンライン   Country:Japan  

  44. テスラ・モデル3分解から読み解くパワー半導体応用戦略とそこから予測する次世代自動車

    山本真義

    EVEX EV-PHV普及活用技術展  2020.11.6  エヌプラス

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    Event date: 2020.11

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

    Venue:東京都   Country:Japan  

  45. 車載応用におけるパワー半導体の熱設計・信頼性技術最前線~テスラ・モデル3分解~読み解くパワー半導体パッケージ戦力~

    山本真義

    ネプコンジャパン  2020.10.22  リードエグジビションジャパン

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    Event date: 2020.10

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

    Venue:愛知県名古屋市   Country:Japan  

  46. テスラ「モデル3」徹底分解セミナー ~分解したらここまで分かる、テスラが示す未来のクルマ~

    山本真義

    日経BP講演会 テスラ分解  2020.9.18  日経BP

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    Event date: 2020.9

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

    Venue:オンライン   Country:Japan  

  47. 航空機電動化

    山本真義

    ÉCLAIRコンソーシアム  2020.9.14  JAXA

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    Event date: 2020.9

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

    Venue:オンライン   Country:Japan  

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Other research activities 1

  1. ⾮接触受電装置および⾮接触給電システム

    2020.10

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    特許出願 特願2021- 19679
    発明者 大矢根 蒼、山本 真義

Research Project for Joint Research, Competitive Funding, etc. 27

  1. ウイルス不活化機能をもつ個人装用型送気服および送気フェイスシールド

    2021.4 - 2022.4

    受託研究費

    山本真義

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\3600000 ( Direct Cost: \3600000 )

  2. GaNパワーデバイス 革新的な省CO2実現のための部材や素材の社会実装・普及展開加速化事業

    2020.10 - 2022.3

    山本真義

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    Authorship:Coinvestigator(s)  Grant type:Competitive

    Grant amount:\29952000 ( Direct Cost: \26133000 、 Indirect Cost:\3819000 )

  3. 低CO2エミッション航空機実現に向けた推進用高出力密度電気モータシステムの研究開発

    2019.11 - 2021.7

    受託研究費

    山本真義

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    Grant type:Competitive

    Grant amount:\17270000 ( Direct Cost: \13387000 、 Indirect Cost:\733000 )

  4. 未来のあるべき社会・ライフスタイルを創造する技術イノベーション事業

    2019.4 - 2022.3

    受託共同研究費

    山本真義

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    Authorship:Coinvestigator(s)  Grant type:Competitive

    Grant amount:\36922000 ( Direct Cost: \34459000 、 Indirect Cost:\2463000 )

  5. 高速スイッチング回路基盤技術の開発

    2018.11 - 2022.3

    受託研究費

    山本真義

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\81975000 ( Direct Cost: \74019000 、 Indirect Cost:\7956000 )

  6. 車両向けパワーエレクトロニクス技術の伝授

    2022.1 - 2023.3

    受託事業費

    山本真義

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    Grant type:Collaborative (industry/university)

    Grant amount:\1346000

  7. 車載向け高周波 絶縁インダクタの研究

    2021.11 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator 

    Grant amount:\3261000 ( Direct Cost: \3076000 、 Indirect Cost:\185000 )

  8. 次世代LED用電源技術の共同研究

    2021.11 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator 

    Grant amount:\2120000 ( Direct Cost: \2000000 、 Indirect Cost:\120000 )

  9. 長距離・大電力のワイヤレス電力伝送技術の研究

    2021.10 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator 

    Grant amount:\1166000 ( Direct Cost: \1100000 、 Indirect Cost:\66000 )

  10. SiCを適用した昇圧DC/DCコンバータのノイズ対策技術の研究

    2021.4 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator 

    Grant amount:\2120000 ( Direct Cost: \2000000 、 Indirect Cost:\120000 )

  11. 電磁波制御技術に関する研究

    2021.4 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator  Grant type:Other

    Grant amount:\2077000 ( Direct Cost: \1966000 、 Indirect Cost:\111000 )

  12. パワーエレクトロニクス技術、パワーコンディショナー及び交流

    2020.11 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator 

    Grant amount:\385000 ( Direct Cost: \385000 )

  13. ツイスト熱電対のノイズ対策についての研究

    2020.10 - 2022.3

    山本真義

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    Authorship:Principal investigator  Grant type:Collaborative (industry/university)

    Grant amount:\814000 ( Direct Cost: \800000 、 Indirect Cost:\14000 )

  14. 次世代自動車電動部品向け新規高機能性薄物シート連続製造技術

    2020.8 - 2022.3

    補助金等

    山本真義

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    Authorship:Principal investigator  Grant type:Other

    Grant amount:\1321000 ( Direct Cost: \1321000 )

  15. ワイドバンドギャップ半導体を用いた電動システムにおけるノイズ対策の研究

    2020.6 - 2021.12

    共同研究

    山本真義

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    Grant type:Other

    Grant amount:\6997000 ( Direct Cost: \6703000 、 Indirect Cost:\294000 )

  16. インバータ回路におけるシャント抵抗を用いたソフトスイッチング

    2020.6 - 2021.3

    山本真義

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    Authorship:Principal investigator  Grant type:Other

    Grant amount:\1338000 ( Direct Cost: \1269000 、 Indirect Cost:\69000 )

  17. GaNを適用したLLC共振絶縁DC/DCコンバータのノイズ対策技術の研究

    2020.5 - 2021.3

    山本真義

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    Grant type:Other

    Grant amount:\1607000 ( Direct Cost: \1538000 、 Indirect Cost:\69000 )

  18. 航空機電動化に向けた高電力密度インバータ設計手法の確立と実証

    2020.4 - 2022.3

    山本真義

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\21994000 ( Direct Cost: \21271000 、 Indirect Cost:\599000 )

  19. ブラシモータ装置の電磁ノイズ解析技術

    2020.4 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator  Grant type:Other

    Grant amount:\1630000 ( Direct Cost: \1538000 、 Indirect Cost:\92000 )

  20. 省エネルギー社会の実現に資する次世代半導体研究開発

    2020.4 - 2021.3

    山本真義

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    Grant amount:\52250000 ( Direct Cost: \50000000 、 Indirect Cost:\2250000 )

  21. 小型・軽量・高効率・低EMC電源を実現する電源基板設計技術

    2020.2 - 2021.3

    山本真義

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    Grant type:Other

    Grant amount:\124000 ( Direct Cost: \113000 、 Indirect Cost:\11000 )

  22. エネルギーマネジメント展開に関する共同研究

    2019.4

    山本真義

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    Grant type:Collaborative (industry/university)

    Grant amount:\256000 ( Direct Cost: \256000 )

  23. 次世代自動車の車内快適性に関する包括的共同研究

    2019.4 - 2021.3

    山本真義

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    Authorship:Principal investigator  Grant type:Collaborative (industry/university)

    Grant amount:\100000 ( Direct Cost: \100000 )

  24. GaNパワーエレクトロニクスに関する研究

    2018.10 - 2022.3

    共同研究

    山本真義

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\800000 ( Direct Cost: \614000 、 Indirect Cost:\186000 )

  25. GaNパワーエレクトロニクスに関する研究

    2018.10 - 2021.3

    山本真義

      More details

    Grant type:Other

    Grant amount:\815000 ( Direct Cost: \769000 、 Indirect Cost:\46000 )

  26. 高出力インバータ回路の開発

    2018.4 - 2021.3

    山本真義

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    Grant amount:\804000 ( Direct Cost: \769000 、 Indirect Cost:\35000 )

  27. 新磁性材料インダクタコアの応用検討

    2017.10 - 2022.3

    共同研究

    山本真義

      More details

    Authorship:Principal investigator  Grant type:Other

    Grant amount:\2341000 ( Direct Cost: \2112000 、 Indirect Cost:\229000 )

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KAKENHI (Grants-in-Aid for Scientific Research) 2

  1. トンネル用LED照明装置

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    Grant type:Competitive

    トンネル用LED照明装置の高効率化、低ノイズ化を実現する

  2. 電気自動車用電源装置の小型軽量化

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    Grant type:Competitive

    車載用電源装置のマルチフェーズ化によるインダクタ部、キャパシタ部の小型軽量化

 

Teaching Experience (On-campus) 11

  1. Electric Circuits with Exercises

    2020

  2. Advanced Experiments and Exercises in Electric Engineering

    2020

  3. Advanced Lectures on Power Electronics Applications

    2020

  4. Power Electronics Seminar 1D

    2020

  5. Power Electronics Seminar 1C

    2020

  6. Power Electronics Seminar 2E

    2020

  7. Power Electronics Seminar 2C

    2020

  8. Power Electronics Seminar 2B

    2020

  9. Power Electronics Seminar 2A

    2020

  10. Power Electronics

    2020

  11. power Electronics

    2020

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Teaching Experience (Off-campus) 1

  1. 特別講義 2030年の次世代電気自動車像とそこで使われるパワーエレクトロニクス応用技術最前線

    2021.12 Okayama University)

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    Level:Undergraduate (specialized)  Country:Japan

 

Social Contribution 3

  1. 2030年の自動車像を予測する ~電気自動車の世界市場展開と新材料半導体~

    Role(s):Lecturer

    名古屋大学  サイエンスフェスティバル2021  2021.11

  2. 次世代パワー半導体が切り開く次世代自動車・航空機・宇宙探査機の世界

    Role(s):Lecturer

    名古屋大学  アカデミックナイト  2020.11

  3. 電気は空へ~電動バイクや電動航空機、宇宙用ロケットや月面探査車の最前線~

    Role(s):Lecturer

    名古屋大学  サイエンスフェスティバル2020  2020.9

Media Coverage 12

  1. フォルクスワーゲン「ID.3」徹底分解 Newspaper, magazine

    日経BP  2022.2

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    Author:Myself 

  2. パワー半導体の高性能化と小型化で、EVの航続距離を伸ばすことができる

    読売新聞  2022.2

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    Author:Myself 

  3. パワー半導体SiC/GaNの課題... 高速スイッチングによるサージと 対策回路への研究 Newspaper, magazine

    CQ出版株式会社  トランジスタ技術 2月号  2022.2

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    Author:Myself 

  4. 次世代EV/HEV用モータの高出力化と関連材料の開発 Newspaper, magazine

    株式会社技術情報協会  2022.1

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    Author:Myself 

  5. 中国の「50万円EV」を分解  機能割り切り格安を実現 Newspaper, magazine

    日本経済新聞  2021.12

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    Author:Myself 

  6. 次世代パワー半導体の開発動向と応用展開EV・HEV用モータと、高出力化に向けた関連材料の開発

    株式会社エヌ・ティー・エス  2021.12

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    Author:Myself 

  7. 次世代自動車2030年ロードマップ Newspaper, magazine

    電波新聞  2021.11

  8. 日本の鉄は赤船に乗るか? ~中国48万円EVの衝撃~ Promotional material

    JRCM NEWS  2021.8

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    Author:Myself 

  9. 航空機産業を支える実力企業 Newspaper, magazine

    日刊工業新聞  2021.5

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    Author:Myself 

  10. MIRAIのみらい TV or radio program

    ZIP-FM  STORY OF MOBILITY  2021.3

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    Author:Myself 

  11. 自動車電動化の潮流 Newspaper, magazine

    日刊工業新聞  2021.2

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    Author:Myself 

  12. 半導体産業EVに不可欠なパワーデバイスの 現状と将来 Newspaper, magazine

    日刊工業新聞  2021.2

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    Author:Myself 

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