Robust Speed Control Strategy of PMSMs Using Improved Sliding-Mode Controller With New Reaching Law and Variable-Parameter Generalized Super-Twisting Observer

This study presents a novel approach to enhance the speed control performance of the permanent magnet synchronous motor (PMSM) drive system by integrating a new sliding-mode reaching law (NSMRL) with a variable-parameter generalized super-twisting observer (VGSTO). The NSMRL is developed based on the terminal attractor concept and an adaptive method. It overcomes the slow convergence of the traditional exponential reaching law. The proposed sliding-mode controller consists of the NSMRL and an integral sliding-mode surface, achieving superior convergence dynamics. Besides, the adaptive function enhances fast transient response. The VGSTO addresses the traditional ESO's issue of limited bandwidth selection due to system stiffness, offering better observing performance without a large bandwidth. The added linear and extra terms further speed up observer convergence. The introduction of variable parameters further reduces the observation error of the observer. Experiments confirm the superiority of the proposed control strategy.