Analysis of Fault Tolerant Control for a Nine-Phase Flux-Switching Permanent Magnet Machine

The fault tolerant capability of electrical machine-based driving systems is extremely important in many applications. Hence, in this paper, two fault tolerant current control strategies for a nine-phase flux-switching permanent magnet (FSPM) machine are proposed and implemented when one or two phases meet the open-circuit fault. The basic concepts of the two control strategies are to keep the rotating magnetomotive force unchanged under both healthy and faulty conditions. Based on the principle, an optimal solution is derived through comparing the magnitudes of fault tolerant currents, average output torque, and torque ripple. The finite element analysis-based predictions of the nine-phase FSPM machine verify the effectiveness and difference of the two fault tolerant control strategies.