Development of physical and phenomenological models of stress-dependent vector magnetic properties of core materials for electric machins

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K06300
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Power engineering/Power conversion/Electric machinery
• Research Institution: Kyoto University
• Principal Investigator: Matsuo Tetsuji 京都大学, 工学研究科, 教授 (20238976)
• Co-Investigator(Kenkyū-buntansha): 藤原 耕二 同志社大学, 理工学部, 教授 (20190093)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 電気機器工学 / 電子・電気材料 / シミュレーション工学

Outline of Final Research Achievements

[1. Development of measuring technique of stress-dependent vector magnetic property] A pair of piezoelectric films is attached to a circular sample of silicon steel sheet in the rotational single sheet tester, wherein the film shrinks to exert compressive stress on the sheet.
[2. Improvements of domain model] The magnetostatic computation is simplified for a fast magnetization analysis under mechanical stress without loss of prediction accuracy. Using the identification method of vector play model, the pinning-field distribution in the domain model is identified from measured BH loops under the stress-free condition.
[3. Study of equivalent stress theory] Equivalent stress models are numerically tested to predict the stress-dependent magnetic property from a unidirectional measurement.

Free Research Field

計算磁気学

Academic Significance and Societal Importance of the Research Achievements

応力下の磁気計測と物理的モデルによるシミュレーションにより，磁化と応力の方向が異なる場合の磁化特性の応力依存性を明らかにするとともに，その結果を用いて，応力依存性を簡潔に表現するためのベクトル等価応力モデルを開発した。この技術を用いて，応力下での計測をすることなく，あるいは最小限の計測に基づき，応力・磁界連成解析を行うことが可能になり，モータ製造時の特性劣化とその要因を評価することが可能になった。