基于EMD-BPNN的逆变器IGBT开路故障诊断方法

Open-circuit Fault Diagnostics Method for IGBT of Inverter Based on EMD-BPNN

绝缘栅双极性晶体管(Insulated gate bipolar transistor,IGBT)作为逆变器的主要组成部分,其工作的稳定性与可靠性对逆变器的正常工作有着重要的影响。针对三相电机牵引逆变器IGBT常见的单管和双管开路故障,提出一种基于经验模态分解(Empirical mode decomposition,EMD)和误差反向传播神经网络(Back propagation neural network,BPNN)相结合的故障诊断方法。首先分析逆变器IGBT单管和双管开路故障的波形特征,采用EMD方法对逆变器输出的三相电流进行分解;在此基础上构造故障特征向量,采用BPNN对特征向量进行训练并实现故障诊断;其次针对EMD方法存在的“模态混叠”问题,采用互补集合经验模态分解(Complementary ensemble empirical mode decomposition,CEEMD)对诊断方法进行了优化;最后在小型试验平台上进行了试验,试验结果表明,基于CEEMD-BPNN的故障诊断方法能够有效诊断出故障功率管。

Insulated gate bipolar transistor(IGBT)is the main component of inverter.Its stability and reliability have great influence on the normal operation of the inverter.To detect the common single-IGBT and double-IGBTs open-circuit fault of inverter,a fault diagnostics method based on empirical mode decomposition(EMD)and back propagation neural network(BPNN)is proposed.Firstly,the waveform characteristics of single-IGBT and double-IGBTs open-circuit fault of inverter are analyzed,and the three-phase current outputs of the inverter are decomposed by EMD.On this basis,the fault eigenvector is constructed and then trained by BPNN to realize the fault diagnosis.Secondly,to solve the mode aliasing in EMD,the diagnostics method is optimized by using complementary ensemble empirical mode decomposition(CEEMD).Finally,the proposed diagnostics method is verified on a low-power testbed,and the experimental results show that the diagnostics method based on CEEMD-BPNN can diagnose the faulty IGBTs effectively.