Sensorless Control of Permanent Magnet Synchronous Machine Based on Improved Sliding Mode Observer

A novel sliding mode control system for permanent magnet synchronous machine (PMSM) is proposed to solve the problem of low position and speed tracking accuracy caused by chattering in sensorless sliding mode control. Firstly, a sliding mode observer constructed with fast double power reaching law and piecewise function is constructed, compared to ordinary sliding mode observers, the introduction of a new type of reaching law effectively improves the estimation speed and accuracy of the system, suppressing the chattering phenomenon, using the arctangent function to extract speed and position information; Secondly, the improved speed sliding mode controller designs the switching gain as an adaptive function, improving the anti-interference performance of the control, suppressing speed overshoot, and improving the robustness of the system. Finally, the stability of the sliding mode control system is proved using Lyapunov theorem. The simulation results show that the designed new sliding mode control system can effectively weaken the chattering phenomenon of the system, improve the robustness of the system, and verify the effectiveness of theoretical analysis.