Improvements on the high frequency signal injection method for permanent magnet synchronous motors and its application in the hybrid drive position control

This paper presents a hybrid rotor position estimation for permanent magnet synchronous motor (PMSM) over wide speed range. At zero and low speeds, a rotor position error compensation scheme is proposed to improve the performance of high frequency signal injection method. This includes the incorporation of system modeling and Kalman filtering to improve the estimation performance during transient. At medium and high speeds, a novel yet simple approach called direct scaling is presented to estimate the rotor position. The two methods are combined in a hybrid scheme and implemented for position control of PMSM drive. Simulation results demonstrate the improvements in the high frequency signal injection method during steady state and transient conditions. The performance of the hybrid sensorless motor drive for wide speed range is also tested via simulations. The obtained results show the effectiveness of the proposed methods over the entire speed range.