Position sensorless switching control strategy of SPMSMs based on fault tolerance of position sensor

This paper proposes a switching method based on model reference adaptive system (MRAS) from position sensor control strategy to sensorless control strategy for surface permanent magnet synchronous motor (SPMSM) drives operating in medium and high velocity regions. The proposed switching method can effectively deal with the fault of the position sensor in SPMSM system, so as to improve its safety and stability. The sensor setting of control strategy consists of an actual sensor (position sensor) and the virtual sensor (MRAS). When the system position sensor has no fault, the feedback value of the position sensor has a greater weight on the information of the rotor position and velocity of the closed-loop system, while the weight of the MRAS estimated value is lower. When the position sensor fails, the information of the rotor position and velocity of the closed-loop system is provided by MRAS algorithm. Also, a linear weighted switching method is proposed, which can effectively reduce the motor fluctuation during the switching process. The feasibility of the proposed strategy is confirmed via simulations of SPMSM drive model in MATLAB/Simulink software.