Vibration Analysis of Permanent Magnet Synchronous Motors Considering Magneto-Thermal Coupling and Structural Deformation

During the operation of a permanent magnet synchronous motor (PMSM), there is an interplay between its electromagnetic performance and temperature distribution. Additionally, thermal stress can cause structural deformation, which in turn impacts the motor's electromagnetic characteristics. Electromagnetic vibration is the primary component of vibration in PMSM. This study focuses on a four-module PMSM, developing a 2D electromagnetic field model and a 3D finite element model of the temperature field to investigate the effects of magneto-thermal coupling on the calculation of electromagnetic excitation in PMSM. A 3D structural finite element model is then constructed to examine the effects of temperature loads on the motor's structure. The displacement of the structure is calculated to reconstruct the electromagnetic field, allowing for an accurate assessment of the electromagnetic excitation forces. Using uncoupled electromagnetic fields, magneto-thermal coupling, and reconstructed electromagnetic fields as excitations, harmonic response analysis is employed to simulate the motor's electromagnetic vibration. Structural modal testing and vibration response testing validate the model's accuracy. The results show that incorporating magneto-thermal coupling reduces simulation errors in the frequency response of radial electromagnetic forces. Additionally, considering electromagnetic field reconstruction enhances the accuracy of vibration calculations in the motor casing at specific frequencies.