A Novel Fault-Tolerant Control Approach for a Six-Phase Motor Drive Under Open-Circuit Faults

This paper proposes a novel fault-tolerant control for a multiphase motor drive. The control is presented in the particular case of a symmetrical six-phase surface-mounted permanent magnet synchronous motor with one neutral point, driven by a three-level six-phase neutral-point-clamped traction inverter. The control covers all 41 possible combinations of open-circuit converter-leg or motor-phase faults. This control is based on a new approach that reduces the control complexity and improves the system dynamic performance. While the conventional approach is based on changing the motor current references or the machine model in the event of faults, the proposed control simply modifies the inverse Clarke transformation matrix in the control loop according to the faults occurred. The proposed approach can also be easily extended to systems with any number of phases. Simulation results are presented to validate the good performance of the proposed fault-tolerant control and illustrate its advantages over a conventional control.