Application of New Sliding Mode Observer in Sensorless Control of Permanent Magnet Synchronous Motor

Abstract

In view of the position sensorless control system of permanent magnet synchronous motor (PMSM) under medium and high-speed conditions, the use of traditional sliding mode observers is prone to problems such as speed and high-frequency jitter and three-phase current distortion. In this paper, a saturation function consisting of an arctangent function is used instead of a discontinuous switch symbol function at the zero point to improve the speed stability and improve the three-phase current distortion problem. Simulations in MATLAB/Simulink compare the speed and three-phase current which is sliding mode observer between the traditional and the improved, the later can effectively suppress the speed jitter and three-phase current distortion.