Research on Electromagnetic Field Analysis Technique considering Permeability Tensor of Core Material for Electric Machinery

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04026
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Kagoshima University
• Principal Investigator: Kai Yuichiro 鹿児島大学, 理工学域工学系, 准教授 (50595436)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 電気機器 / 磁気特性 / 鉄心材料 / 透磁率テンソル / 電磁界解析 / 磁気計測

Outline of Final Research Achievements

Core materials for electrical machine are magnetized under alternating and rotating magnetic flux conditions, and have magnetic anisotropy which the magnetization differs depending on the excitation direction. In this research, we have been clarified and modeled the permeability tensor of the core materials, and developed an electromagnetic field analysis technique for electric machine that takes the permeability tensor into account. At first, we developed a measurement system to evaluate the magnetic properties of the core materials from four directions. Next, the magnetic permeability tensor was measured under the alternating and rotating magnetic flux conditions, and the differences in the permeability tensor under various magnetic flux conditions were clarified with the developed system. Finally, the permeability tensor is considered in the analysis of electrical machine, and the validity of the analysis results is demonstrated.

Free Research Field

電気機器，磁気工学，磁気計測，磁界解析

Academic Significance and Societal Importance of the Research Achievements

一般に，透磁率テンソルは磁束密度ベクトルと磁界強度ベクトルを結びつける物理量であり，磁気異方性を表すことができる。よって，鉄心材料の磁気異方性を正確に考慮した電磁界解析を行うためには，すべての透磁率テンソルの値を測定し，その挙動を明らかにすることが重要と考えられる。将来的には，透磁率だけでなく，応力，磁歪の関係をテンソル量として統一して表現できる新たな磁性材料のモデリングを開発し，その応用を目指す。さらに，電気機器設計へと応用することで鉄心材料の応力問題や騒音・振動問題を考慮した機器構造の検討が可能となり，高効率・低損失な新しい機器設計・開発が期待できる。