Analysis of Natural Frequency of the Stator of Interior Permanent Magnet Synchronous Motor

Analysis of natural frequency is essential to analyze the vibration and noise of permanent magnet motors. This paper presents an improved analytical method (AM) for calculating the natural frequency of stators of interior permanent magnet synchronous motor (IPMSM). This method can overcome the shortcoming of the previous analytical method in which the influence of stator teeth on the natural frequency of stators is simply treated as an additional mass. A 36-slot 6-pole IPMSM is analyzed by AM and finite element method (FEM). Both FEM and AM results show that the improved method is accurate for estimating the vibration and acoustic noise. The damped sandwich is proved to be useful to weaken electromagnetic vibration.