Research on sensorless control of HSPMSM based on a discrete full-order sliding mode observer

To address the inaccuracy of the observed rotor position caused by the large estimated back-electromotive force harmonics of the high-speed permanent magnet synchronous motor (HSPMSM) under the conventional sliding mode observer, this paper presents an adaptive full-order sliding mode observer for back-electromotive force (EMF) based on the accurate mathematical model of the HSPMSM in the discrete-time domain. The accuracy of the sliding mode observer is improved under high-speed operating conditions by using the proposed method. To further reduce the harmonic component of the observed back EMF, a synchronous fundamental frequency extraction filter (SFEF) is used to obtain the back EMF, and then, the extracted observed EMF is fed in;to the normalized phase-locked loop to obtain the rotor position. The simulation results in Matlab are presented to demonstrate the feasibility and effectiveness of the proposed method.