A Study on the Effects of Rotor Step Skewing on the Vibration and Noise of a PMSM for Electric Vehicles

Radial force F r is the main cause of electromagnetic vibration and noise in motors. In this study, the vibration and noise characteristics of a permanent magnet synchronous motor (PMSM) with consideration of rotor-step skewing are investigated. Firstly, the analytical model of F r considering rotor-step skewing is deduced based on the Maxwell stress tensor method. The influence of rotor-step skewing on F r of the PMSM is then analysed and summarised. Taking a 65 kW PMSM commonly used in electric vehicles as an example, combined with electromagnetic finite element analysis, F r is then evaluated. Secondly, an electromagnetic vibration and noise simulation analysis is conducted based on a multi-physical field joint simulation platform, from which the influence of rotor-step skewing on the vibration and noise is then summarised. Finally, a noise experiment is then carried out. The results obtained from the multi-physical analysis and the tests conducted are presented to validate the precision of the simulation models, and the accuracy of the analytical model of F r .