Modeling and control of five-phase permanent magnet synchronous motor with one phase open-circuit fault

To improve the reliability of five-phase permanent magnet synchronous motor (PMSM) control system and reduce the ripple components of output torque when the stator windings occur open-circuit fault, this paper proposed an effective fault-tolerant control strategy for five-phase PMSM. Based on the viewpoint of vector space decoupling, a mathematical model of the five-phase PMSM with third harmonic injection was established. According to the power conservation principle, the electromagnetic torque was analyzed under normal state and fault state, then a fault-tolerant control strategy with unchanged average torque was proposed. This method realizes full-load operation by reallocating the amplitude and phase of the phase current. To obtain a smooth electromagnetic torque under fault state, another fault-tolerant control strategy was then proposed keeping the pulsating torque at zero, which realizes no-disturbed operation. By controlling the electric currents of dq axis and zero sequence in the rotating coordinate system, the electromagnetic torque was compensated. The experimental results show that the proposed fault-tolerance control strategy can improve the running performance of five-phase PMSM under fault state.