Sliding Mode Control Strategy For PMSM Based on Improved Reaching Law

The sliding mode control method with double power exponential reaching law is proposed for the unstable factors such as chattering vibration and overshoot in the sliding mode control of permanent magnet synchronous motor. The method combines the advantages of the traditional reaching law, which enables the motor to approach the sliding mold surface quickly and smoothly from the initial state, and realizes the speed tracking. And the continuous function is chosen to instead of the sign function, which suppresses the chattering phenomenon of the sliding mode control. Comparing the designed new reaching law with the traditional reaching law in simulink, it can be clearly seen that the time from the system movement to the sliding surface is significantly shortened. And at the same time, in the case of uncertain disturbance, the motor can adjust the motion state faster, indicating that the new reaching law has better stability and tracking performance than the traditional reaching law.