Novel Anti-disturbance Speed Regulation System for PMSM Drives Based on Sliding Mode Control

A novel sliding mode control strategy is proposed to enhance the robustness of permanent magnet synchronous motor (PMSM) drive systems subjected to time-varying parameters and external disturbances. The traditional exponential approach law (TEAL) is first revisited, and its inherent limitations—such as reduced tracking precision and insufficient disturbance rejection—are analyzed. To overcome these drawbacks, a novel exponential approach law (NEAL) is developed, aiming to improve system convergence and anti-disturbance performance. The proposed NEAL-based control scheme is systematically compared with the TEAL approach through both theoretical analysis and numerical simulations, highlighting superior transient response and enhanced disturbance suppression. Furthermore, system stability under NEAL is rigorously proven using Lyapunov stability theory. The proposed control method is then validated through detailed simulation models and real-time experiments, confirming its effectiveness in achieving accurate speed regulation, strong disturbance rejection, and overall system stability. The results demonstrate the feasibility and practicality of the NEAL-based SMC in high-performance PMSM drive applications.