Anti-Windup Integral Terminal Sliding Mode Control of PMSM System Based on Improved Variable Speed Approximation Law

To solve the problems of high-frequency chattering and robustness of traditional sliding mode control, as well as to overcome the Windup phenomenon caused by the nonlinear saturation characteristics of PMSM system, this paper proposes a novel anti-windup integral terminal sliding mode (AWl-TSM) control strategy. In the design of sliding mode surface, an integral non-singular terminal sliding mode surface is designed, where the power term of the system state is introduced to improve the dynamic performance in the sliding stage. Meanwhile, the system is ensured to converge quickly in finite time through the joint action of the remote power term and the state power term of control law. Specifically, the saturation deviation disturbance terms are introduced to the control law purposefully to overcome the overshoot phenomena and its stability is derived. Finally, numerical simulation and experimental results demonstrate the superiority of the proposed method with over 50% improvement in vibration suppression, fast response and control accuracy in terms of disturbance transient performance.