Torque Performance Optimization of Permanent Magnet Motor with Open Circuit Fault Based on BQGA and Current Harmonic Injection

Permanent magnet synchronous motor (PMSM) would occur the problem that the average torque decreases and the torque ripple increases significantly while single-phase open circuit fault occurring, which would affect the reliability and safety of the system including the motor furtherly. Simultaneously, for the PMSM in the field of aerospace, it is quite challenging to optimize the torque performance only according to the torque analytical model while it is in fault, and the satisfactory accuracy is also difficult to be achieved. In this paper, the Quantum genetic algorithm based on Bloch coordinates (BQGA) and three-dimensional finite element method (3DFEM) are combined and the strategy of injecting harmonic current into the remaining normal phase is proposed to optimize the torque performance while single-phase open circuit fault occurring. The result shows that this method could reduce the torque ripple significantly at the expense of reducing little average torque while the motor is in open circuit fault condition. Concurrently, because less dependence on the internal mechanism analysis of the motor, this method could be migrated to optimize the motor performance while other faults occurring conveniently and thus it has the guiding significance for the fault tolerant control of the system including this motor.