基于三相电流残差的功率管多管开路故障诊断

Multiple Open-circuit Faults Diagnosis in Inverter Based on Three-phase Current Residual

牵引逆变器是电力牵引交流传动系统的重要组成部分,它的可靠性直接影响着机车的安全稳定运行,其主电路功率管(IGBT)是最易发生故障的部分。针对IGBT的多管开路故障,提出了一种基于三相电流残差的多管开路故障快速在线诊断方法;通过分析牵引逆变器在正常条件和各开路故障类型下的三相电流,得出了发生多管开路故障情况下的三相电流残差特征;利用控制系统中的电流给定信号重构参考三相电流与实测电流进行运算,并根据三相电流残差特征进行故障定位。最后给出了半实物实验结果,验证了该诊断方法能够快速实现IGBT单管及双管开路故障诊断,且不受闭环控制和负载扰动影响。

The inverter plays an important role of traction systems, which directly affects the safety and reliability stable operation on drive system. The IGBT is the most vulnerable part of the inverter. Thus, to detect the open-circuit fault of the IGBT in inverters, an efficient and general diagnostic method with line current residual is proposed. The characteristics of the three-phase current residual of multiple IGBTs open circuit is analyzed by comparing the inverter operation modes of normal and faulty conditions. With the comparison of prescribed current and actual current, three- phase current residuals are figured out. And the current residuals is used for fault diagnosis. Experimental results validate the efficiency and accuracy of this method. It is fast to diagnose the single and dual open-circuit faults ,which is not affected by the closed loop control and load disturbance.