A PMSM model incorporating structural and saturation saliencies

Sensorless permanent magnet synchronous motor (PMSM) drive systems have become very attractive due to their advantages, such as the reduction of hardware complexity and hence the reduced system cost and increased reliability. In order to accurately determine the rotor position required for correct electronic commutation, various methods have been proposed. Among them, the most versatile makes use of the structural and/or magnetic saturation saliencies of the PMSM. This paper presents a non-linear model for PMSMs with the saliencies. The phase inductances of a PMSM are measured and expressed by Fourier series at different rotor positions according to their patterns. The dynamic performance of the PMSM is simulated and compared with that based on a model without considering saliency to verify the effectiveness of the proposed model.