Study of Fault-tolerant Control Strategies for a Fault-tolerant Permanent Magnet Motor

The fault-tolerant permanent magnet motor (FTPMM) drive has good fault-tolerant capacity and is widely used in various electric actuation systems. On the base of analyzing the structure of FTPMM and H-bridge inverters, the basic principles and fault-tolerant control strategies based on space vector pulse width modulation (SVPWM) and current hysteresis band pulse width modulation (CHBPWM) are elaborated. The fault-tolerant control strategy based on SVPWM is achieved by keeping the synthesized magneto motive force (MMF) of the motor circular and unchanged, and the fault-tolerant control strategy based on CHBPWM is to maintain the same output torque before and after the open-circuit fault occurs. Finally, the correctness of the proposed current vector fault-tolerant control strategies based on SVPWM and CHBPWM are verified by computer simulations.