Fault-Tolerant Control Strategy for Five-Phase PMSM With Third-Harmonic Current Injection

As the third-harmonic air-gap magnetic motive forces (MMFs) can be well utilized to improve the torque density, more and more research has been studying the postfault control for a five-phase permanent-magnet synchronous motor with trapezoidal back electromotive force (EMF). This paper presents a new reduced-order fault-tolerant control (FTC) scheme for the FPMSM with trapezoidal back EMF under single-phase open-circuit fault. Firstly, third reduced-order transformation matrices with third-harmonic current injection, the postfualt five-phase machines can not only realize an undisturbed MMF but also maintain high electromagnetic torque. Finally, the results verify that the proposed FTC strategy on reduced-order model can realize the single-phase open-circuit fault-tolerant and show fast dynamic response capability even under FTC condition.