Low-Vibration Fault-Tolerant Control for Dual Three-Phase PMSM Using Hybrid Modulation With Fixed Carrier Frequency

In order to improve the vibration performance of dual three-phase permanent magnet synchronous motor (PMSM) drives under open-phase fault condition, a fault-tolerant control strategy with low vibration performance is proposed in this paper. The virtual healthy model, where the control structure and mathematical model remain unchanged under open-phase fault condition, is adopted in the proposed method. The undisturbed fault-tolerant performance can be obtained. To further suppress the vibration due to the carrier frequency harmonics without compromising the fault-tolerant performance, the hybrid modulation is proposed. The space vector pulse width modulation (SVPWM) with the frequency-doubled effect is constructed, where the frequency of harmonics is twice as the carrier frequency. The hybrid modulation is achieved by randomly selecting the traditional SVPWM and frequency-doubled SVPWM while maintaining the fixed carrier period and sampling period. Hence, the torque and current performance can hardly be deteriorated. The vibration can be reduced due to the dispersion of high frequency harmonics. The amplitude of high frequency current harmonics and vibration are reduced by about 50%. Experimental results are presented to verify the proposed method.