Adaptive Anti‐Disturbance Sliding Mode Speed Control of PMSM Using Dual Reaching Laws

ABSTRACT Sliding mode control (SMC) for permanent magnet synchronous motor (PMSM) drives faces two critical limitations: the inherent conflict between convergence speed and chattering suppression, and the difficulty in balancing disturbance rejection and control accuracy under strong disturbance conditions. To resolve these issues, this paper proposes an adaptive disturbance‐rejection sliding mode speed control method based on dual reaching laws. Firstly, a dual‐control‐law architecture is introduced for the first time. In this architecture, the speed loop employs an adaptive variable‐speed reaching law (AVSRL), thereby achieving an optimal balance between transient response and vibration suppression. The disturbance observer uses an improved exponential reaching law (IERL), enabling fast and stable disturbance estimation while preventing vibration. Secondly, a nonlinear integral sliding surface (NISMS) with the characteristic of “small errors amplified, large errors saturated” is developed. This sliding surface ensures system convergence within a finite time and eliminates integral saturation. By combining the NISMS with the IERL, an extended sliding mode disturbance observer (ESMDO) is constructed, allowing for high‐precision estimation and compensation of disturbances in permanent magnet synchronous motors. Finally, a nonlinear adaptive sliding mode controller (NASMC) is designed based on this observer, resulting in a comprehensive disturbance suppression control framework that integrates observation, compensation, and control. Simulation and experimental results show that the proposed control method outperforms existing schemes in terms of dynamic response, vibration suppression, and disturbance rejection.