Implementation of Postfault Decoupling Vector Control and Mitigation of Current Ripple for Five-Phase Fault-Tolerant PM Machine Under Single-Phase Open-Circuit Fault

The multiphase machine is a competitive candidate for applications where uninterrupted operation is demanded under postfault conditions. In this paper, the decoupling vector control for a surface mounted five-phase permanent-magnet synchronous machine (PMSM) under single-phase open-circuit fault is investigated. The decoupled mathematical model of the five-phase PMSM under single-phase open-circuit fault is derived. Then, two postfault control strategies are obtained, which are based on the principles of minimum copper loss and equal amplitudes of currents, respectively. The postfault control strategy based on the feed-forward compensation is proposed in order to eliminate the influences of certain factors and decrease the current ripple. The validity of the postfault control strategies is proved by experiments.