Faculty Profiles - HASEGAWA, Kazunori

Other Link： https://www.jstage.jst.go.jp/article/ieejjournal/145/6/145_333/_pdf

Research Group Introduction: Power Electronics Laboratory, Dept. of Electrical and Electronic Engineering, Kyushu Institute of Technology

IEEJ Transactions on Industry Applications ( The Institute of Electrical Engineers of Japan ) 145 ( 6 ) NL6_8 - NL6_8 2025.06

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

This article introduces Power Electronics Laboratory at Department of Electrical and Electronic Engineering, Kyushu Institute of Technology, which focuses on reliability-related issues of power electronic converters including power semiconductor devices and capacitors.

DOI： 10.1541/ieejias.145.nl6_8

Other Link： https://kyutech.repo.nii.ac.jp/records/2001952

A Condition-Monitoring Method of a DC-Link Capacitor in a V2X Bidirectional EV Charger Reviewed International journal

Nagano Tomoyuki, Hasegawa Kazunori, Yamate Shigeki, Tokii Atsushi

IEEJ Journal of Industry Applications ( The Institute of Electrical Engineers of Japan ) 14 ( 3 ) 505 - 506 2025.05

Language：English Publishing type：Research paper (scientific journal)

This letter presents a condition-monitoring method of a DC-link capacitor in a vehicle-to-everything (V2X) bidirectional electric vehicle (EV) charger. EVs have gained considerable attention because of portable energy sources, thereby resulting in the development of V2X bidirectional EV chargers. Surveys of reliability in power electronics indicare that 20-30% of converter failures are attributed to capacitors. The proposed method enables condition monitoring of DC-link capacitors for the charge or discharge output changes.

DOI： 10.1541/ieejjia.L24000916

Other Link： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105004213654&origin=inward

Lifetime Diagnosis Technologies of Power Electronic Converters

HASEGAWA Kazunori

The Journal of The Institute of Electrical Engineers of Japan ( The Institute of Electrical Engineers of Japan ) 145 ( 2 ) 94 - 97 2025.02

九州工業大学IoTネットワークイノベーション実証研究センターの活動

長谷川一徳

電気学会誌 ( 一般社団法人電気学会 ) 145 ( 1 ) 49 - 49 2025.01

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

はじめにSociety 5.0の実現には，サイバー空間とフィジカル空間の融合による持続可能で強靭な社会への変革，新たな社会を設計し価値創造の源泉となる知の創出，そして新たな社会

DOI： 10.1541/ieejjournal.145.49

Other Link： https://www.jstage.jst.go.jp/article/ieejjournal/145/1/145_49/_pdf

Condition Monitoring of a DC-Link Capacitor Using the Instantaneous Output Power of a Propulsion Inverter with One-Pulse Modulation Reviewed International journal

Hasegawa Kazunori, Yamasoto Takuma, Fujimoto Kazuki, Oyama Yuji, Iida Norifumi

IEEJ Journal of Industry Applications ( The Institute of Electrical Engineers of Japan ) advpub ( 0 ) 2025.01

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

Condition-based maintenance (CBM) is an effective approach for ensuring the safe operation of power electronic converters used in industrial applications, grid-tied ones, and transportation systems. This paper proposes a condition-monitoring method of a DC-link capacitor used in a propulsion inverter for a rolling stock, where capacitance is used as the indicator of its degradation. This method utilizes the instantaneous output power of the inverter to reproduce the ripple current of the dc-link capacitor, which allows current-sensor-less condition monitoring of the dc-link capacitor. In addition, the capacitor voltage is obtained from a sampled one synchronized to a multiple of the carrier frequency available in a practical propulsion inverter. A 200-V 1.5-kWlaboratory system with an induction motor is designed and constructed for emulating the propulsion inverter with synchronous pulse-width modulation in a region with constant output power. Experimental results confirmed that the capacitance of the dc-link capacitor was monitored from the sampled voltage and reproduced ripple current with the proposed method.

DOI： 10.1541/ieejjia.20250328

Accurate ESR Monitoring of a DC-Link Capacitor with Switching Ripple Voltage by a Leafony Invited Reviewed International journal

Yusaku Ogawa, Takuma Yamasoto, Kazunori Hasegawa

International Conference on Renewable Energy Research and Applications (ICRERA) 1521 - 1525 2024.11

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (international conference proceedings)

日本長崎 2024.11.09 - 2024.11.13

DOI： 10.1109/ICRERA62673.2024.10815310

Other Link： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85217176815&origin=inward

日本初の浮体式洋上風力発電所を訪ねて

長谷川一徳

電気学会誌 ( 一般社団法人電気学会 ) 144 ( 9 ) 603 - 603 2024.09

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

2024年3月7日～8日に電気学会電力技術／電力系統技術／半導体電力変換合同研究会が長崎県五島市（福江島）にて開催された。本研究会は毎年3月にIEEE Power & En

DOI： 10.1541/ieejjournal.144.603

Other Link： https://www.jstage.jst.go.jp/article/ieejjournal/144/9/144_603/_pdf

Power-cycling degradation monitoring of an IGBT module with V<inf>CE(sat)</inf> measurement in continuous operation of a chopper circuit Reviewed International journal

Hasegawa K., Hara K., Shishido N., Nakano S., Saito W., Ninomiya T.

Power Electronic Devices and Components 7 2024.04

Observation of Thermal-Resistance Increase of Degraded IGBT Modules by VCE(sat) Measurement in a Chopper Circuit Reviewed International journal

Hasegawa K., Ueda H., Hara K., Shishido N., Nakano S., Saito W., Ninomiya T.

PCIM Europe Conference Proceedings 2024-June 2997 - 3001 2024.01

Current-Sensor-Less Condition Monitoring of a DC-Link Capacitor Based on Analysis of a Six-Pulse Diode Rectifier Having AC and DC inductors Reviewed International journal

Hasegawa K., Hirose Y.

IEEE Transactions on Industry Applications 60 ( 6 ) 9043 - 9051 2024.01

Conference Report: IE (Intelligent Electronics) Competition in 2023 Power Electronics Annual Conference of KIPE July 4-6, 2023, Welli Hilli Park, Hoengseong, Republic of Korea

IEEJ Transactions on Industry Applications ( The Institute of Electrical Engineers of Japan ) 143 ( 12 ) NL12_16 - NL12_16 2023.12

Analysis and Measurement of the Surge and Gate-Noise Voltages in a 1.7-kV IGBT Module With the Effect of Reverse-Recovery Current Reviewed International journal

Hasegawa K., Takagi K.

IEEE Transactions on Power Electronics 38 ( 7 ) 8051 - 8055 2023.07

Online Cell Capacitance and ESR Monitoring Using Switching Frequency in a Modular Multilevel Converter Reviewed International journal

Yasuda Takumi, Hasegawa Kazunori, Itoh Jun-ichi

IEEJ Journal of Industry Applications ( The Institute of Electrical Engineers of Japan ) advpub ( 0 ) 953 - 960 2023.01

Language：English Publishing type：Research paper (scientific journal)

A cell capacitor is one of the most fragile components in a modular multilevel converter (MMC). Capacitance decreases and equivalent series resistance (ESR) increases, as the capacitor deteriorates. This paper proposes an online monitoring method for both the capacitance and ESR of the cell capacitors in an MMC without any additional components or operation. The proposed method measures the impedance of the cell capacitor not only at a low frequency but also at a switching sideband-frequency of the cell without current sensors for capacitor current. The high-frequency components around the switching frequency improve the estimation accuracy compared with the previous methods that measure only impedance at low frequencies. The experimental results confirm that the proposed method estimates the capacitance and ESR with errors of 3.1% and 8.8%, respectively.

DOI： 10.1541/ieejjia.22009850

Other Link： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85171361496&origin=inward

Current-Sensor-Less Condition Monitoring of a DC-Link Capacitor in a PWM Inverter With a Six-Pulse Diode Rectifier Reviewed International journal

Hasegawa Kazunori, Kubo Tsukasa, Hirose Yuto

IEEJ Journal of Industry Applications ( The Institute of Electrical Engineers of Japan ) 12 ( 3 ) 548 - 554 2023.01

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

Condition monitoring helps improve the reliability of power electronic converters including their dc-link capacitors because it can predict converter failure and degradation. In practice, however, condition monitoring usually utilizes current sensors to obtain health condition, which is a constraint with regard to cost. This paper proposes a current-sensor-less condition monitoring method of a dc-link capacitor in a three-phase PWM inverter with a front-end six-pulse diode rectifier and a dc inductor. The proposed method measures both the capacitance and equivalent-series resistance (ESR) of the capacitor without using current sensors. Theoretical analysis reveals that the capacitor current is calculated using the three-phase ac source voltage and the dc inductor. Experimental results obtained from a 200-V laboratory system confirmed that both the ESR and capacitance changes were observed without using current sensors.

DOI： 10.1541/ieejjia.22009135