Fault Tolerant Control for Open Winding Brushless DC Motor with Power Device Failure

Brushless DC motors are widely used in electric drive equipment. But the neutral port in conventional BLDCM windings could lead to torque ripples and low reliability. Each phase winding of the open winding BLDC is connected to an H-bridge inverter, and its phase voltage and phase current could be controlled independently, which has a certain fault tolerance. Firstly, the circuit topology and conduction mode of the open-winding brushless DC motor are introduced, and a Matlab simulation model is established according to the mathematical equation of the motor. Then, the operation characteristics of the open winding brushless DC motor with power device failure are analyzed, and the characteristics of two fault-tolerant control methods, compensation and reconstruction, are discussed. Finally, the open winding brushless DC motor and controller are processed, and the experimental platform is built to verify the operation characteristics of the open winding brushless DC motor with normal operation and compensation operation. The experimental results show that the compensation method can ensure the continued operation of the faulty motor, while increasing the current of the remaining phase winding.