Reduction of Cogging Torque and Electromagnetic Vibration Based on Different Combination of Pole Arc Coefficient for Interior Permanent Magnet Synchronous Machine

Abstract

Cogging torque and electromagnetic vibration are two important factors for evaluating permanent magnet synchronous machine (PMSM) and are key issues that must be considered and resolved in the design and manufacture of high-performance PMSM for electric vehicles. A fast and accurate magnetic field calculation model for interior permanent magnet synchronous machine (IPMSM) is proposed in this article. Based on the traditional magnetic potential permeance method, the stator cogging effect and complex boundary conditions of the IPMSM can be fully considered in this model, so as to realize the rapid calculation of equivalent magnetomotive force (MMF), air gap permeance, and other key electromagnetic properties. In this article, a 6-pole 36-slot IPMSM is taken as an example to establish its equivalent solution model, thereby the cogging torque is accurately calculated. And the validity of this model is verified by a variety of different magnetic pole structures, pole slot combinations machines, and prototype experiments. In addition, the improvement measure of the machine with different combination of pole arc coefficient is also studied based on this model. Cogging torque and electromagnetic vibration can be effectively weakened. Combined with the finite element model and multi-physics coupling model, the electromagnetic characteristics and vibration performance of this machine are comprehensively compared and analyzed. The analysis results have well verified its effectiveness. It can be extended to other structures or types of PMSM and has very important practical value and research significance.