三电平逆变器IGBT的开路故障诊断研究

针对三电平逆变器开关器件中IGBT的开路故障,研究单桥臂上多种故障形式,提出了测量二极管桥臂上两端电压作为故障信息,以分析每一种故障情况的诊断模型,然后根据故障信号和小波函数的特点,利用小波变换将故障信号转化为故障特征向量,采用SVM来进行故障诊断。为了提高诊断精度利用改进的布谷鸟优化算法进行参数寻优,得到最优模型,实现了多种故障的诊断分类。通过对二极管钳位三电平逆变器仿真进行验证,诊断结果准确可靠,验证此方法的可行性。

Study on open-circuit Fault diagnosis of the IGBT in three-level inverter

In allusion to the open-circuit fault in the insulated gate bipolar transistor (IGBT) of the three-level inverter,a fault diagnosis method of measuring the voltage on both ends across the diode bridge wall as fault information to analyze each fault condition is proposed by studying on multiple fault form of single bridge wall .Then the fault signal can be converted to feature vector with wavelet transform theory according to the features of the fault signal and the wavelet function ,and support vector machine(SVM) is applied to fault diagnosis. In order to improve the diagnostic accuracy, the improved cuckoo optimization algorithm is used to optimize parameters, so as to get the optimal model to realize the multiple fault diagnosis classification. By the simulation of diode clamp three-level inverter , the accuracy diagnostic results show the feasibility of this method.