Fault-Tolerant Control for a Symmetrical Dual Three-Phase SPMSM Drive under Two-Phase Open-Circuit Fault

Multiphase machines have been attracting more and more attentions in high-reliability-required applications due to their inherent fault-tolerant capability. This paper addresses key issues in postfault decoupling modeling and fault-tolerant control (FOC) for the dual three-phase surface-mounted permanent magnet synchronous machine (DTPSPMSM) with isolated neutrals under arbitrary two-phase OCF. To do so, a postfault decoupling model with reduced-order transformation is established. Postfault current references are reconfigured based on the decoupled model. Furthermore, third harmonic flux linkage/back-EMF are taken into account in modeling and control, since it causes third harmonic currents and hence torque ripples under single-phase OCF. The validity of the postfault control strategies is proved by simulation results.