Sensorless operation of PMSM based on hybrid rotor position self-sensing scheme

A hybrid rotor position self-sensing scheme was investigated by combining the rotating high-frequency voltage signal injection method and Model Reference Adaptive System (MRAS) method in this paper. Based on the detailed discussion of the basic principles and the merits for the two methods, the configuration of the hybrid scheme and the transition principle from high-frequency signal injection method to MRAS were studied and the estimation algorithm of the rotor position/speed and weight coefficients in the transition region was deduced in detail. Moreover, the experimental verification for the smooth transition of the two position estimation schemes in an inset-type Permanent Magnet Synchronous Motor (PMSM) using the hybrid approach and the sensorless vector control operation were carried out with success as well. The experimental study indicates that the hybrid rotor position self-sensing approach merges the advantages of both methods and is capable of precisely estimating the rotor position and speed at the low speed and possessing fast dynamic response at the high-speed. Therefore, the proposed scheme is suitable for sensorless vector control of a PMSM in a wide speed region, including zero-speed.