A novel fast and chattering-free speed control method for PMSM motor drive based on sliding mode control

To enhance the accuracy and convergence speed of the control algorithm for speed control of permanent magnet synchronous motors, this article presents a novel method based on sliding mode control. In physical systems, model uncertainty usually has an unknown bound. Therefore, during the design of sliding mode controllers, the designers increase the coefficient of the sign functions so much that the closed-loop system becomes stable. But by doing this, they increase the chattering and thus the system error. This article presents a new reaching law based on which a sliding controller is designed to eliminate the chattering phenomenon in the presence of unknown uncertainties. Furthermore, by incorporating a well-suited sliding surface during the controller's design, the chattering phenomenon is significantly reduced, resulting in a notably rapid convergence of the controller. To assess the performance of this method, a series of practical tests were conducted to control the permanent magnet synchronous motor. The results of these tests, when compared to the conventional sliding method, demonstrate that the proposed approach achieves a faster convergence speed of 3 ms and superior tracking accuracy of 5 rpm.