High-frequency Model of Permanent Magnet Synchronous Motor for EMI prediction in Adjustable Speed Drive System

With the superior features of lower cost and higher power density, the permanent magnet synchronous motor (PMSM) based adjustable speed drive (ASD) system has been paid much more attentions recently. A high-frequency (HF) model of PMSM is proposed to predict the conducted electromagnetic interference (EMI) emission, which brings much detrimental affection to the ASD system, in this paper. This model can depict the impedance characteristics of a three-phase surface-mounted PMSM from 0.1 kHz to 10 MHz well. Then, experiment is implemented to validate the proposed HF model for EMI prediction. The experimental results manifest that the model is able to calculate CM voltage, CM current, and phase current of the PMSM in a simplified ASD system correctly. Therefore, the proposed HF model of PMSM is expected to provide much more instructions for EMI predicting in the ASD system.