Research on PMSM Position Sensorless Control Based on Improved Sliding Mode Observer

In order to solve the problem of chattering and other problems in the rotor position estimated by the traditional sliding mode observer, a rotor position estimation method for a permanent magnet synchronous motor based on an improved sliding mode observer is proposed. The chattering is suppressed by using a saturation function and a phase-locked loop method. To improve the accuracy of rotor position estimation, and to reduce the influence of high-frequency noise on the estimation of back-EMF, an adaptive low-pass filter was introduced. Using Lyapunov stability theory, the stability of the improved sliding mode observer is proved. Both simulations and experiments show the effectiveness of the improved sliding mode observer.