Fast Prediction and Staged Optimization of Electromagnetic Vibration in Permanent Magnet Synchronous Motor

The most common method to suppress electromagnetic vibration is to weaken the electromagnetic force harmonics, which are the vibration sources. Clearly, vibration is related to some other factors, too. Therefore, in this article, a modal analytical model and the transmission function of a permanent magnet synchronous motor are studied, based on which a fast analytical method of predicting the electromagnetic vibration is proposed, so that the vibration can be preliminarily evaluated during the machine electromagnetic design. The time-consuming 3-D finite-element method is not needed when predicting the vibration. Moreover, using the fast prediction method, a 15-D multiobjective optimization problem for vibration, torque, and efficiency performances is solved in stages. After optimization, the vibration is greatly reduced, and the torque performance is improved. The proposed methods are also proved to be applicable for different operating conditions and types of motors with various slot-pole combinations.