Vibro-acoustic prediction and evaluation of permanent magnet synchronous motors

In this study, a multiphysics finite element method is proposed to predict and evaluate the electromagnetic vibration and noise of the permanent magnet synchronous motors. First, the expressions of radial electromagnetic force waves were derived based on the established mathematical models of airgap magnetic field using the analytical methods. Subsequently, the main circumferential spatial orders influencing electromagnetic noise were analyzed and discussed. Then, a multiphysics simulation model that consists of mechanical field, electromagnetic field, and acoustic field was established for the calculation of the electromagnetic radiation noise. Finally, the multiphysics simulation model developed for the electromagnetic vibration and noise prediction was validated by comparing the finite element analysis and experimental data. It is shown that, although the local differences exist, the results from the finite element calculation and test analysis have a good agreement on the analytical mechanism overall, both in amplitude and main orders. In addition, this paper has made a detailed analysis to the electromagnetic noise generation mechanism, which lays the basis for further study in predicting and suppressing the electromagnetic vibration and noise of the drive motors of pure electric vehicle.