Hybrid nonsingular terminal sliding mode control for permanent magnet synchronous motor drive system

To improve dynamic quality of permanent magnet synchronous motor (PMSM) speed servo system, the hybrid nonsingular terminal sliding mode control method (HNTSM) was proposed. The advantages of the linear sliding mode (LSM) and nonsingular terminal sliding mode (NTSM) were combined, the singular problem of the terminal sliding mode (TSM) was solved by this method. In addition, the faster convergence speed of system state variables could be obtained during the whole process. The novel control method was applied to the PMSM speed servo system, a novel sliding mode speed controller was designed to replace the traditional PI regulator. Simulation and experimental results show that the novel speed controller can improve steady, dynamic performances and robustness of speed servo system obviously.