Faculty Profiles - YAMAMOTO Masayoshi

Papers - YAMAMOTO Masayoshi

Division display 41 - 60 of about 197 ／ All the affair displays >>

Derivation of Resonant Period for Soft Switching Considering Nonlinear Characteristics of Output Capacitance in Switching Device Reviewed

Sihoon Choi, Ayato Suzuki, Jun Imaoka, Masayoshi Yamamoto

IEEJ Journal of Industry Applications Vol. 70 ( 6 ) page： 289 - 294 2023.5

Investigation on Relationship between Common Mode Noise and Distribution of Parasitic Capacitance Reviewed

Mamoru Sasaki, Jun Imaoka, Masayoshi Yamamoto

IEEJ Journal of Industry Applications Vol. 12 ( 3 ) page： 484 - 492 2023.5

Current Sharing Control of Multi-Input Modular DC-DC Converter Using Unregulated LLC Resonant Converter Reviewed International journal

Piao Qingyun, Imaoka Jun, Yamamoto Masayoshi

IEEJ Transactions on Industry Applications Vol. 143 ( 4 ) page： 337 - 348 2023.4

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Institute of Electrical Engineers of Japan

By applying an unregulated LLC resonant converter to a multi-input modular DC-DC converter (MIMC), the LLC converter can be operated at an optimal frequency while achieving power source flexibility. However, the output characteristics of an LLC converter are easily affected by the resonance parameter, and when connected in parallel, the output current is unbalanced. In this paper, we propose a current sharing control method to solve the current imbalance problem, and automatically balance the output current of each module. The effectiveness of the proposed current sharing control method is verified by simulations and experiments.

DOI： 10.1541/ieejias.143.337

Scopus

CiNii Research

Common Mode Conductive Noise Cancellation for Multiphase Converter Using Auxiliary Winding Reviewed International journal

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

IEEJ Transactions on Industry Applications Vol. 143 ( 4 ) page： 263 - 272 2023.4

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Institute of Electrical Engineers of Japan

A multiphase DC-DC converter consisting of a coupled inductor and fast switching devices enables power electronics equipment to achieve a high power density. However, with such devices, the fast voltage transition generates substantial common mode (CM) noise. However, there are very few studies on CM noise reduction for multiphase converters using a coupled inductor. Therefore, in this paper, a CM noise reduction method is proposed for a multiphase DC-DC converter that hardly lowers the power density.

DOI： 10.1541/ieejias.143.263

Scopus

CiNii Research

補助巻き線による結合インダクタ方式多相コンバータ用コモンモードノイズキャンセル Invited Reviewed

佐々木守, 今岡淳, 山本真義

電気学会論文誌Ｄ 2023.4

非制御 LLC共振形コンバータを用いたモジュラーDC-DCコンバータの電流分担制御 Reviewed

朴青云, 今岡　淳, 山本真義

電気学会論文誌D Vol. 143 ( 4 ) page： 337 - 348 2023.4

Gate Drive Circuit Suitable for a GaN Gate Injection Transistor Reviewed

Fumiya Hattori, Yuta Yanagisawa, Jun Imaoka, Masayoshi Yamamoto

IEEE Access Vol. 12 ( 3 ) page： 43169 - 43182 2023.4

補助巻き線による結合インダクタ方式多相コンバータ用コモンモードノイズキャンセル Invited Reviewed International journal

佐々木守, 今岡淳, 山本真義, 仲野陽, 布施浩司

電気学会論文誌D Vol. 143 ( 4 ) page： 263 - 272 2023.4

パワー半導体基板内蔵技術による SiC ハーフブリッジ回路の設計・試作・評価 Reviewed

中村和人, 今岡淳, 山本真義, 金山天, 韓榮建, 加藤義尚, 末次正, 服部篤典, 野北寛太, 稲田太朗, 浅井寛美, 小泉雄大

エレクトロニクス実装学術講演大会講演論文集 Vol. 37 ( 0 ) page： 15C4-2 2023.3

Novel measurement method to determine optimum reception frequency of electric field wireless power receiver Invited Reviewed

A. Oyane and M. Yamamoto

IEEJ Journal of Industry Applications Vol. 12 ( 1 ) page： 54 - 64 2023.1

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

IEEJ Journal of Industry Applications Vol. 12 ( 1 ) page： 86 - 93 2023

Novel Measurement Method to Determine Optimum Reception Frequency of Electric Field Wireless Power Receiver Reviewed International journal

Oyane Aoi, Yamamoto Masayoshi

IEEJ Journal of Industry Applications Vol. 12 ( 1 ) page： 54 - 64 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：The Institute of Electrical Engineers of Japan

This paper proposes a novel method for measuring the characteristics of a wireless power receiver of an electric field wireless power transfer (eWPT) system. The proposed measurement method allows us to obtain the frequency response of the eWPT receiver's power-receiving characteristics with respect to the spatial electric field frequency. Conventionally, it was not possible to measure the reception characteristics of a single independent receiver. This is because a resonant eWPT transmitter has pronounced frequency dependent characteristics. As a result, frequency-dependent electric fields are emitted into space and act on the receiver. The proposed measurement method overcomes this obstacle by using the proposed device that generates a high-frequency electric field almost independently of the frequency. The proposed device generates high-frequency electric fields in space by using a terminating resistor instead of resonator circuits. Therefore, unlike resonant transmitters, the strength of the electric field generated by the proposed device does not exhibit a large frequency dependence. The proposed measurement method will also be useful for the prototyping, evaluation, and optimization of new advanced eWPT systems whose characteristics are not yet fully understood. Here, 85kHz series resonant eWPT receivers are evaluated using the proposed measurement method, and the details of this experimental device are also described.

DOI： 10.1541/ieejjia.22004096

Web of Science

Scopus

CiNii Research

Accurate Leakage Inductance Modeling Using an Artificial Neural Network Based on the Dowell Model Reviewed

Wu Yu-Hsin, Shigematsu Koichi, Omoto Yasumichi, Ikushima Yoshihiro, Imaoka Jun, Yamamoto Masayoshi

IEEJ Journal of Industry Applications Vol. advpub ( 0 ) 2023

Authorship：Last author Language：English Publisher：The Institute of Electrical Engineers of Japan

This study proposes strategies for improving the accuracy and usefulness of leakage inductance modeling using the Dowell model (DM). As the analytical method of modeling the leakage inductance model considers geometrical factors, it is vital for front-loading transformer design. DM is one such widely used one-dimensional magnetic field-based approach for analytically modeling both AC resistance and leakage inductance. It is more accurate and requires less computational work than other analytical approaches proposed in previous studies. However, some approximations may cause errors and eventually lead to inaccurate results. Therefore, this study aims to ascertain the conditions that result in inaccurate leakage inductance modeling. Additionally, a simple exponential-based model and an artificial neural network are developed to increase the accuracy of inaccurate modeling. The results clarify the conditions that result in a frequency-dependent and bias error. Moreover, the intended findings indicate that the proposed strategies effectively improve modeling accuracy while simultaneously providing some extra advantages for transformer design.

DOI： 10.1541/ieejjia.22007452

CiNii Research

Balanced Two-phase Interleaved Boost Converter with Integrated Magnetics for Common-Mode Noise Reduction Invited Reviewed

Nagai Tomotaka, Sasaki Mamoru, Imaoka Jun, Yamamoto Masayoshi, Nakano Akira

IEEJ Journal of Industry Applications Vol. advpub ( 0 ) 2023

Authorship：Corresponding author Language：English Publisher：The Institute of Electrical Engineers of Japan

This paper presents an interleaved boost converter with integrated magnetics for common-mode (CM) noise reduction without introducing electromagnetic interference (EMI) filters. The noise reduction is realized using the balanced technique, which is an effective CM noise reduction technique from a circuit topology perspective. The application of this technique addresses the issue of the CM noise, while avoiding an increase in circuit volume due to EMI filters. Additionally, an interleaved circuit topology and integrated magnetics contribute to realizing the high-power density converter. The effectiveness of the proposed converter is discussed through theoretical analyses, simulations, and experiments.

DOI： 10.1541/ieejjia.22007783

CiNii Research

Fixed Frequency Operation in Critical Conduction Mode with Voltage-Controlled Variable Inductor Reviewed International coauthorship International journal

Choi S., Shin J.W., Imaoka J., Yamamoto M.

2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023 page： 6444 - 6449 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023

This study introduces a novel voltage-controlled variable inductor (VI) that effectively fixes the switching frequency of DC-DC converters operating in the critical conduction mode (CRM). The proposed VI addresses the limitations encountered with conventional current-controlled VIs, such as complex winding structures, control challenges, and reliance on magnetic saturation. In the proposed voltage-controlled VI, the primary-side inductance of a coupled inductor is regulated by an auxiliary voltage source on the secondary side. The validity of the proposed VI is experimentally verified using a prototype CRM boost converter with an output voltage of 400 V. Experimental results demonstrate that the switching frequency remains fixed at 100 kHz, and the main converter maintains soft switching characteristics regardless of variations in output power.

DOI： 10.1109/ECCE53617.2023.10362859

Scopus

Modeling of Lithium-Ion Batteries with Constant Phase Element and Butler-Volmer's Equation Reviewed International journal

Yamahigashi T., Shimura J., Shibuya K., Wu Y.H., Shigematsu K., Hosotani T., Kuromi J., Imaoka J., Yamamoto M.

ICPE 2023-ECCE Asia - 11th International Conference on Power Electronics - ECCE Asia: Green World with Power Electronics page： 697 - 702 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：ICPE 2023-ECCE Asia - 11th International Conference on Power Electronics - ECCE Asia: Green World with Power Electronics

An equivalent circuit model of lithium-ion batteries which has a nonlinear resistor governed by Butler-Volmer's equation and a constant phase element was investigated. The current dependence of the real battery could be reproduced well by the contribution of the nonlinear resistor, and the transient response of voltage could be reproduced well by the contribution of the constant phase element.

DOI： 10.23919/ICPE2023-ECCEAsia54778.2023.10213775

Scopus

Investigation on Relationship between Common Mode Noise and Distribution of Parasitic Capacitance Reviewed

Sasaki Mamoru, Imaoka Jun, Yamamoto Masayoshi

IEEJ Journal of Industry Applications Vol. 12 ( 3 ) page： 484 - 492 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：The Institute of Electrical Engineers of Japan

This study investigates the influence of parasitic capacitance on the common mode (CM) noise in a converter. A thermal pad on a switching device is necessary for sufficient heat dissipation. In addition, the thermal pad increases the CM capacitance between the printed circuit board and the ground plane. The parasitic capacitances form CM noise propagation paths. However, which node in the circuit and the corresponding parasitic capacitance influences the CM noise the most and the degree of the parasitic capacitance influence on the CM noise are unclear. In this study, the parasitic capacitance that influences the CM noise in a converter is identified, and the extent to which the parasitic capacitance affects the CM noise is investigated through simulations and experiments.

DOI： 10.1541/ieejjia.22008018

Web of Science

Scopus

CiNii Research

High reliable transformer-less deadtime less Inverter for Grid-connected Applications Reviewed International coauthorship International journal

Senanayake S., Senanayake T., Imaoka J., Yamamoto M.

ICPE 2023-ECCE Asia - 11th International Conference on Power Electronics - ECCE Asia: Green World with Power Electronics page： 1788 - 1794 2023

This paper presents a transformer-less inverter topology that brings out the high-performance for grid connected inverters. The main advantages of this inverter eliminate the dead-time requirement, and allows both top and bottom switch from being on at same time, and thus shorting the DC bus supply to ground. This avoids the freewheeling diodes connected across the switches for loads other than purely resistive. Low output voltage distortion and low fundamental and common voltages losses result in high efficiency and high output power density. The input dc source and the output ac voltage share the same ground in proposed inverter, which effectively eliminates the leakage current caused by the DC source (PV panel, battery bank etc.). Analysis and simulation results are presented to demonstrate the effectiveness of the proposed inverter. Compared to the prior literature mentioned in this paper, 75- 86% reduction of semiconductor components is achieved with proposed inverter topology.

DOI： 10.23919/ICPE2023-ECCEAsia54778.2023.10213921

Scopus

Gate Drive Circuit Suitable for a GaN Gate Injection Transistor Reviewed International journal

Hattori, F; Yanagisawa, Y; Imaoka, J; Yamamoto, M

IEEE ACCESS Vol. 11 page： 43169 - 43182 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE Access

A GaN gate injection transistor (GIT) has great potential as a power semiconductor device. However, a GaN GIT has a diode characteristic at the gate-source, and a corresponding gate drive circuit is thus required. Several studies in the literature have proposed the gate drive circuits with the speed-up capacitors, but adding these capacitors complicates the gate drive circuit, and increases both the drive and reverse conduction losses. Moreover, driving a GaN GIT with such gate drive circuits becomes more susceptible to the false turn-on. In this paper, a gate drive circuit suitable for a GaN GIT without a speed-up capacitor is proposed. This type can provide the high-speed switching, and exhibit the low gate drive loss and reverse conduction loss. The proposed circuit also has high immunity against the false turn-on and stable gate-source voltage before and after startup. The drive loss of the proposed type is calculated and its validity is confirmed experimentally. Furthermore, the drive loss of the proposed type is compared with the conventional circuits. The result shows that the drive loss of the proposed type is improved by up to 50 %, compared with the conventional type. Finally, the proposed type is experimentally tested to drive a buck converter at the switching frequency of 150 kHz. The entire loss of the converter can be reduced by up to 9.2% at 250 W, compared with the conventional type.

DOI： 10.1109/ACCESS.2023.3270261

Web of Science

Scopus

Design of Coupled Inductor Using Powder Core with Concentrated Air Gap in Multiphase Operation Reviewed International coauthorship

Sihoon Choi, Jun Imaoka and Masayoshi Yamamoto

IEEE Transactions on Industry Applications 2023

　 PREV - NEXT 　

<YAMAMOTO Masayoshi>

Papers - YAMAMOTO Masayoshi