The optimal design and research of interior permanent magnet synchronous motors for electric vehicle applications

Abstract

AbstractAn interior permanent magnet synchronous motor (IPMSM) with “VV—” shape rotor topology structure is proposed, and its performances are compared with “V” shape and “V—” shape rotor topology structure. The results show that the performances including output average torque, reluctance torque, torque ripple, cogging torque, iron loss of the IPMSM with “VV—” shape is better than the other two rotors. Firstly, the parameters which have great influence on the torque and the efficiency of the IPMSM are analyzed and optimized. The no‐load back electromotive force (EMF) of three different optimized rotor topology structures are analyzed and compared, the results show that the no‐load back EMF of the IPMSM with “VV—” shape topology structure has the lowest total harmonic distortion rate (THD). Secondly, the torque of the IPMSM with “VV—” shape under different current angles, current densities and speeds are analyzed and compared with the other two rotors. The results show that the torque performance of the IPMSM with “VV—” shape rotor topology structure is better than that of the other two. Finally, aiming at the problems that the torque ripple and cogging torque of the IPMSM with “VV—” shape rotor topology structure are greatly increased when the iron loss is reduced, This paper proposes to add a set of circular flux isolation holes between the second layer and the third layer of permanent magnets, and the position and diameter of this set of circular flux isolation holes are optimized and adjusted. The results show that the torque ripple and cogging torque of the IPMSM with the further optimized “VV—” shape rotor topology structure are greatly reduced, and the THD of no‐load back EMF is also further reduced, which has great significance to reduce vibration and noise, improve the control accuracy of the IPMSM.