Fault-tolerant control of PMSM based on NTSMC and NLFO

In this work, a reliable fault-tolerant control scheme is proposed for open-circuit faults of the drive in a three-phase permanent magnet synchronous motor (PMSM) control system. A three-phase four-switch fault-tolerant topology drive is employed to guarantee the continuous operation after fault occurrence. A non-singular terminal sliding mode control (NTSMC) scheme is proposed to improve the robustness and the dynamic performance of the post-fault system. To estimate the information of fault, a nonlinear learning fault observer is constructed. Based on the fault information, a compensation term is added to the control scheme against the adverse effects of the transition process. Simulation results show that the proposed fault-tolerant control scheme enables the system to track the desired reference commands in the absence/presence of faults with satisfactory performance and achieves smooth transition for control law switching.