Development of novel optical probe current sensor for in-situ current measurement of power circuit

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02152
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21030:Measurement engineering-related
• Research Institution: Shinshu University
• Principal Investigator: Sonehara Makoto 信州大学, 学術研究院工学系, 准教授 (30456496)
• Co-Investigator(Kenkyū-buntansha): 佐藤 敏郎 信州大学, 学術研究院工学系, 教授 (50283239) ; 宮地 幸祐 信州大学, 学術研究院工学系, 准教授 (80635467)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 磁界センサ / 磁気光学効果 / 磁性材料

Outline of Final Research Achievements

The optical probe current sensor developed by the applicants can measure the current flowing through the terminals of the power device of the power supply circuit composed of power devices such as SiC in-situ, not only to improve the efficiency of the power supply circuit but also to improve the efficiency of the power supply circuit. Since the surge current can also be measured, improvement in safety can be expected. The Faraday element of the sensor unit, a small magnetizing yoke, an optical-electric conversion circuit, etc. were implemented, and the sensor unit could be downsized to 125um, which is the same diameter as the optical fiber. When the same sensor was used in a double pulse test circuit simulating a power supply circuit, the temporal change (high-speed) of the current was 1.8 kA / us, and the noise floor was 10% higher than that of the commercially available Rogoski coil. It was possible to reduce it and satisfied the initial target.

Free Research Field

磁気工学

Academic Significance and Societal Importance of the Research Achievements

次世代電源回路の開発・使用において、本センサを用いてin-situ電流測定が可能になると、高効率な電源回路が実現でき、カーボンニュートラルや温暖化抑止に貢献できる。またサージ電流も測定可能なため例えば電気自動車や電動航空機など電動モビリティの安全性向上にも貢献できる。以上のように社会的意義は極めて高い。高いFaraday効果を有するグラニュラー磁性膜の開発や、同材料をセンサ部とする光プローブ式センサの研究・開発事例は少なく学術的にもインパクトがあり、実施期間中に当該テーマに関する招待講演を4件頂いた。コロナ禍で発表が滞っていたが、2022年度以降に研究成果を多数公表する予定である。