三相八开关逆变器的容错控制策略

针对中性点箝位型（NPC）三电平逆变器的容错拓扑及其控制问题，考虑逆变器发生功率器件断路故障情况以及故障前后空间矢量的变化，当故障发生时，将输出端子连接到直流链路的中性点，建立可容错三电平逆变器模型，实现开路故障下的容错控制。同时考虑逆变器直流侧中点性电压平衡问题，采用零序电压注入法，抑制了中性点电位的波动。仿真结果证明了该容错控制策略的可行性和有效性。

Fault-Tolerant Control Strategy for Three-Phase Eight-Switch Inverter

For the fault tolerance topology of neutral point clamped (NPC) three level inverter and its control problem, considering the case of inverter power devices open circuit fault and the change of space vector after the fault occurs, the fault tolerant three level inverter model is set up by connecting the output terminal to the neutral point of the DC link, so as to implement fault tolerant control under open circuit fault. At the same time, considering the neutral point voltage balance in the DC side of the inverter, zero sequence voltage injection method is adopted to suppress the fluctuation of neutral point potential. Simulation results show that the fault tolerant control strategy is feasible and effective.