Adaptive Nonsingular Terminal Sliding Model Control for Permanent Magnet Synchronous Motor Based on Disturbance Observer

In order to shorten the response time and improve robustness for a permanent magnet synchronous motor (PMSM) control system, an adaptive nonsingular terminal sliding model control (NTSMC) equipped with a disturbance observer is presented for PMSM. First, an improved exponential reaching law is adopted to adaptively adjust exponential and constant approach speed in the adaptive NTSMC. Second, the disturbance observer is devised to observe the load torque and external disturbance and feeds back them to the adaptive NTSMC to compensate. Simulation and experimental results applied to PMSM show that the proposed approach can quickly track load torque and external disturbance and the system has advantages of small overshoot, static error, rapidity, and higher robustness.