通过分析三相桥式脉宽调制(PWM)整流器的开关管开路故障时空间电压矢量的变化情况,提出一种基于修正开关模式的开关管开路故障容错控制算法,对比分析修正前后电压矢量的变化,给出具体的实现方法。该方法对于单管和多管同时开路故障均能实现容错控制,能较好地改善故障下三相电流平衡度,减小直流侧电压纹波,提升系统性能和可靠性,实现算法简单,无需增加硬件电路。仿真与实验验证了该方法的有效性。
Through detailed analysis of changes of voltage space vectors after the switch open-circuit fault in threephase bridge pulse wdith modulation(PWM) rectifier,a fault tolarent control method of open-circuit faults is proposed based on revising the PWM switching patterns,and changes of voltage vectors before and after revising is comparatively analysed.Specific implementation are given.This method can deal with both single and multi switch fault cases with simple software algorithm and no additonal circuit.Furthermore,the balance of three-phase currents is improved greatly,the voltage ripple of the DC-link is minimized,the performance and reliability of system are enhanced.Both computer simulation and experimental results verify the usefulness of the proposed fault tolarent control method.