单元串联变频器IGBT故障诊断方法

Transistor fault diagnosis method in cascade multilevel inverter

针对单元串联多电平高压变频器的IGBT(绝缘栅双极型晶体管)故障检测问题,基于镜像电流源原理,搭建通过功率单元直流母线电压控制的逆变桥臂输出电压逻辑检测电路,并给出功率单元输出逻辑与驱动信号逻辑的关系,通过动态判别逻辑关系的正确性,诊断出IGBT的故障状态。实验结果表明,该方法诊断迅速,能够在10μs以内正确检测出功率管的故障状态,相比基于各种算法的故障诊断方法,该方法可靠实用,对单元串联型多电平高压变频器的故障诊断具有工程应用价值。

As for the problem of fault diagnosis of the IGBT（ insulated gate bipolar transistor） for cascade multilevel inverter, a detection method is designed. It detected logic state of the output of inverter＇ s bridge arm based on the principle of the mirror current method. The DC bus voltage of power module controlled the detection circuit. Then, the logical relationship between the output and drive signal of power module was analysed. The fault state of IGBT was detected though judging this relationship. The experiment results show that the detection method can diagnose IGBT＇s fault state rapidly within 10μs. It is more reliable and practical than the diagnosis methods based on software algorithm, which is valuable in engineering application for the cascade multilevel inverter.