Nonsingular fast terminal sliding mode control method and its application on permanent magnet synchronous motor

To improve the dynamic performance of permanent magnet synchronous motor(PMSM) drive system, a nonsingular fast terminal sliding mode control strategy was proposed. In this control strategy, the mathematical expression of nonsingular fast terminal sliding mode surface and reaching law with terminal attractor were designed. The proposed scheme can guarantee the faster convergence of system state variables during the whole process. In addition, the problems of singular in terminal sliding mode was solved by this method. The novel control method was applied to the PMSM speed servo system, and compared with the traditional terminal sliding mode regulator and PI regulator. Simulation and experimental results show that the proposed control strategy can improve dynamic, steady performance and robustness.