Fault-Tolerant Control of Modular Permanent Magnet Synchronous Motor Under Open-Circuit Faults

The paper studies a novel fault-tolerant strategy of the modular permanent magnet synchronous motor under open-circuit faults, which is called as the extended open-circuit fault-tolerant control (EOCFTC) strategy. The faulty modular motor based on the EOCFTC strategy can achieve the high fault-tolerance and maximum output torque capability by making the most of the remaining healthy phases. First, the mathematical model of the modular motor with n modules is described. Then based on the characteristics of the modular motor, a novel winding reconstruction strategy is proposed to deal with multiphase open-circuit faults in different modules. All remaining healthy phases are reasonably reconstructed according to the maximum output torque principle. Then these new modules can operate well by employing the armature magnetomotive force (MMF) compensation and the field-orientated control (FOC) strategy. Finally, all cases of open-circuit faults and the corresponding processing methods are discussed. The extreme case of open-circuit faults is described in detail, which shows the high fault-tolerance of the modular motor with the EOCFTC strategy. The experimental results verify the rationality and feasibility of the EOCFTC strategy on a two-module modular motor.