Improved Sensorless Control Method for Permanent Magnet Synchronous Machines Considering Resistance Asymmetry and Temperature Variation

This paper aims to improve the sensorless control performance for permanent-magnet synchronous machines (PMSMs) under resistance asymmetry. The improved sensorless method can eliminate the undesired 2nd order fluctuation in position and speed estimation with the help of sequence component extractor (SCE) while the DC offset position error caused by asymmetric resistance and temperature variation can be compensated by applying a novel pulse injection method. Experimental and simulation results are provided to validate the proposed methods.