Sliding-Mode Control of PMSM Speed Loop Based on Adaptive Power Reaching Law

In order to solve the problems of poor dynamic control and large chattering in the speed control system of permanent magnet synchronous motor (PMSM), a sliding-mode control strategy based on adaptive power reaching law is developed in this paper. First, the motion of the system state at different stages under the action of the traditional power-reaching law is analyzed. Second, a new reaching law is designed using the mapping relationship of functions, and the reaching law parameters can be dynamically adjusted according to the system state. Then, the reaching law is used to design the velocity loop sliding-mode controller and perform the Lyapunov stability analysis. Finally, the motor speed is controlled by an adaptive power-law speed-loop sliding-mode controller with Simulink software and compared with a conventional power-law reaching-law controller. The results show that the new controller designed in this paper reduces the speed overshoot after starting the motor, enhances the dynamic response of the system and effectively weakens the sliding-mode chattering, and has good dynamic and static performance.