Control strategy for four phase open faults of dual three-phase PMSG

Multi-phase motors and generators are regarded with great fault tolerance, especially on open-circuit faults. Various mathematic analytical methods are applied for their fault control. In this paper, a novel fault-tolerant control strategy, based on the dual three-phase PMSG system, is proposed for better electrical and dynamical performance of the machine. Innovative mathematical model for PMSG under different open-circuit faults are established considering the asymmetry of the machine. Targeted decoupling transformation of each kind of open-circuit faults are settled by voltage equations under different faults. Besides, special connection for control strategy with zero-sequence current and an improved control loops with two layers are introduced as well, with which the PMSG system acquires less harmonics in phase current and smoother electromagnetic torque. Simulation results of open-circuit faults from one to four phases are provided for verification of the theoretical analysis.