Fault-Tolerant Control Strategy for Reduced Torque Ripple of Independent Twelve-phase BLDC Motor Drive System under Open-Circuit Faults

Multi-phase BLDC (Brushless DC electric motor) are increasingly used in traction or propulsion applications due to their higher efficiency, power density and relatively easy control. The stable operation of these multi-phase BLDC motors in propulsion systems of large capacity during various fault scenario without generating large torque ripple and ohmic loss is an important engineering topic. In this paper, a novel fault-tolerant control method for multi-phase BLDC motor drive systems under an open-circuit failure of single-phase stator winding. The proposed method is to control the phase angles of the healthy phases in which the magnitude of the controlled phase current is increased to a minimum so that the torque ripple is minimized. The superior performance of the proposed concept as compared to the prior arts are demonstrated through the simulation model of independent 12-phase BLDC motor.