Thermal Analysis of Fifteen-Phase Permanent Magnet Synchronous Motor Under Different Fault Tolerant Operations

In order to not change the space vector pulse width modulation (SVPWM) control strategy during one phase fault, the five-phase six-bridge arm SVPWM fault tolerant control method for fifteen-phase permanent magnet synchronous motor (PMSM) is proposed in this paper, and the thermal stress of fifteen-phase PMSM under different fault-tolerant operations is analyzed. Firstly, the control model of the fifteen-phase PMSM based on three dq axes is established, the generation mode of the SVPWM is analyzed, and the speed and current loop PI regulators of the control system are designed. Secondly, the fault-tolerant control principle of the five-phase six-bridge arm is analyzed and compared with the hysteresis control strategy of equal amplitude and minimum stator loss. Thirdly, the 3D model of the fifteen-phase PMSM is established, the steady-state temperature and the transient temperature rise considering operating conditions under different fault tolerant operations are analyzed, and corresponding temperature rise results of the stator armature windings are compared separately. Finally, the experimental platform is established, the phase current waveforms tested under load conditions confirm the theoretical analysis of five-phase six-bridge arms and hysteresis control, and the test results of steady-state and transient temperature rise confirm the correctness of the simulation prediction.