Synchronous reluctance motor speed control based on multivariable Super-Twisting

In order to address issues such as high chattering and insufficient anti-disturbance performance in Synchronous Reluctance Motor (SynRM) speed control systems, this paper proposes an Adaptive Multi-variable Super-Twisting Sliding Mode (AM-STSM) control strategy. First, based on the mathematical model in d-q coordinates, the torque generation principle of SynRM is analyzed. Based on this, an AM-STSM speed controller is designed by introducing time-varying gain terms, achieving rapid convergence when far from the sliding surface and effective suppression of chatter when approaching it. Furthermore, an adaptive Luenberger observer (ALDO) is constructed to observe and compensate for lumped disturbances, significantly enhancing system robustness. In “torque realization” mode, a “Maximum Torque Per Amperage control strategy” is adopted to improve stator current utilization. Simulation and experimental results demonstrate that compared to traditional STSM control methods, the proposed ALDO-AM-STSM approach achieves faster convergence during no-load startup (21.21% reduction). Under sudden load and unload conditions, the speed drop ( decreased by 82.67%), speed overshoot ( decreased by 88.95%), and adjustment time (sudden load: decreased by 47.97%; sudden unload: decreased by 50.36%) are all significantly decreased. Meanwhile, torque and speed fluctuations during steady-state operation are minimized. This control strategy effectively enhances the dynamic performance and anti-disturbance capability of the SynRM speed control system.