Design for Sensorless Permanent Magnet Synchronous Motor Servo System Based on Sliding-Mode Observer

In order to improve the control performance of PMSM servo system, on the basis of analyzing the mathematical model of PMSM, a sensorless control strategy of PMSM servo system based on sliding-mode observer was presented. To solve the chattering problem of sliding-mode observer, the integrator was replaced by Low-Pass Filter(LPF), and the coefficient of LPF was correspond with sliding-mode observer. Vector control of position sensorless PMSM was constructed based on Field Oriented Control theory and parameters estimated by sliding-mode observer. Experimental results show that the proposed strategy had stronger robustness and control performance.