Less rare-earth magnet-high power density hybrid excitation motor designed for Hybrid Electric Vehicle drives

This paper presents an investigation into design possibility of hybrid excitation motor as less-permanent magnet and high power density for traction drives in Hybrid Electric Vehicles. Firstly, the construction, the basic working principle and the design concept are overviewed. Then, the reason why the proposed machine is suitable for realizing the motor with less-permanent magnet and high power density is summarized. After making the design restrictions and specifications clear, 3D-FEA-based preliminary design results are demonstrated. As the design result, the proposed motor makes possible to reduce the volume of permanent magnet by approximately half of that used in existing Interior Permanent Magnet Synchronous Motor for LEXUS RX400h while keeping the power density intact.