Improved Non-Singular Fast Terminal Sliding Mode Control and Disturbance Observer for PMSM

This paper proposes a non-singular fast terminal sliding mode control and non-singular fast terminal sliding mode disturbance observer compound control strategy for permanent magnet synchronous motor. Firstly, by introducing a new reaching law, the imbalance issue between chattering and convergence speed in the conventional reaching law is solved. To further enhance the system's capacity to restrain disturbances, a non-singular fast terminal sliding mode disturbance observer is proposed to estimate the disturbance value and provide feedback to the speed controller. The non-singular fast terminal sliding mode disturbance observer reduces sliding mode chattering and enhances observer response speed compared to sliding mode disturbance observer. Simulation consequences demonstrate the effectiveness and superiority of the proposed control method.