面向复合故障的牵引逆变器四桥臂容错控制

针对牵引变流器中NPC型三电平逆变器在一相或两相桥臂发生复合故障后的容错控制问题,在给出三电平逆变器四桥臂容错拓扑及其控制方式的基础上,通过分析逆变器主桥臂冗余矢量容错能力,归纳出复合故障类型,并就不同类型故障提出相冗余与矢量冗余相结合的容错控制策略,最终通过仿真建模对复合故障容错控制策略进行验证。仿真结果表明,三电平逆变器两相桥臂同时发生故障时可实现自动容错,故障后系统仍可全额或降额持续运行,验证了所提控制策略的有效性。

Four-Leg Fault-Tolerant Control of Traction Inverter for Composite Fault

For the problem of fault-tolerant control when the composite fault occurs in one or two phase of NPC three-level traction inverter, the four-leg fault-tolerant topology and its control mode of the three-level inverter is presented. On analyzing the fault-tolerant ability of three main legs with their redundant vectors, the composite fault of invert is classified. And the corresponding fault-tolerant control strategy with the combination of redundant vector and redundant phase is also put forward for the different types of fault. Finally, a simulation is built to verify the validity of the control strategy hereof. The result shows that the fault-tolerant control could be put into the inverter system automatically when the fault happens on two phase simultaneously. And after that, the inverter could keep running in full or derate operation, which means the control strategy above is effective.