Hybrid-Type PM Motor for Electric Vehicle Traction with improved Reluctance Torque

抄録

This paper proposes a novel hybrid-type permanent magnet motor (HPMM) that simultaneously applies ferrite-PM (Fe-PM) to reduce the amount of NdFeB permanent magnet (Nd-PM) used in electric vehicle traction motors. Conventional HPMM can be divided into parallel type (P-HPMM) and series type (S-HPMM). P-HPMM is advantageous for PM torque improvement because it can obtain high PM flux linkage, but there is a problem in that Fe-PM is demagnetized due to the strong magnetic flux of Nd-PM. S-HPMM is the way to fundamentally solve these problems. However, it is difficult to improve PM flux linkage compared to P-HPMM. Therefore, in this paper, a novel rotor topology that can effectively generate reluctance torque by improving S-HPMM is proposed. The target motor is the 2018 NISSAN LEAF^TM traction motor. The proposed motor has the same torque density as the target motor, while reducing Nd-PM usage by 38%.