Copperless coreless motors driven by microwave frequency electromagnetic fields

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18716
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Yokohama National University
• Principal Investigator: Fujimoto Yasutaka 横浜国立大学, 大学院工学研究院, 教授 (60313475)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 電気機械エネルギー変換 / モータ / マイクロ波 / 共振結合

Outline of Final Research Achievements

Recently, wireless power transmission based on MHz-band magnetic field resonance has attracted much attention, and an MIT study showed that large power transmission is possible. The researchers applied this to propose a theory of electromechanical energy conversion in the MHz band and further attempted to extend it to the GHz band. A microwave circuit design consisting of a stator and a rotor was developed, and a model of microwave transmission through an air gap was proposed. Finite element simulations confirmed that the proposed circuit could generate a small but significant force. In addition, power losses inside and outside the waveguide were analyzed and compared. As a result, it was found that the power loss inside the waveguide is in good agreement. However, the calculated power loss outside the waveguide is much more significant than the value obtained by the theoretical model.

Free Research Field

電気機器学

Academic Significance and Societal Importance of the Research Achievements

現在のモータや発電機の研究開発では、完成された従来の電気機械エネルギー変換工学の基本原理に立脚して、効率や出力密度の向上など多くの取り組みが行われている。近年のモータの性能向上は、磁石材料の改良や冷却機構の改善によるところが大きいが、基本原理の枠組みの中での改良であるため、今後、性能が大幅に改善したり特性が大幅に変質したりすることは難しい。本研究の高周波電気-機械エネルギー変換は、従来のものより電源周波数が6桁ほど高く、その機械的構造や原理が大きく異なっている。本研究でシミュレーションと理論により力の発生が確認できたことにより、新しいモータや発電機の可能性を拓いた。