Prediction of Electromagnetic Vibration with Discrete Force-Response Matrix for Permanent Magnet Synchronous Motor

In view of the actual characteristics of electromagnetic (EM) force are ignored in existing vibration calculation models, this article proposes a hybrid calculation model based on discrete force-response matrix for predicting EM vibration. Initially, the subdomain method is employed to calculate the air gap force density (AGFD). Based on the mapping principle of air gap force, an equivalent distributed force model is introduced, which accounts for the the uneven distribution of radial and tangential EM forces on the tooth heads. Next, a frequency response function (FRF) model is developed to correspond with the distributed force. This model incorporates the circumferential variation of the FRF and the differences in distribution patterns are analyzed. Subsequently, a vibration prediction model based on multi-point excitation and multi-point response method is established. Finally, the accuracy of the proposed model is validated through vibration testing of the prototype, and the motor’s vibration modes are also confirmed.