基于平均模型的三相四线制逆变器多管开路故障诊断

Multi-transistor Open-circuit Fault Diagnosis in Three-phase Four-wire Inverter Based on Average Model

为了在不增加额外硬件电路的情况下,实现三相四线制逆变器多管开路故障快速准确的诊断,提出了一种基于平均模型及误差自适应阈值的方法。该方法通过计算平均桥臂中点电压实际值和期望值的偏差,来进行故障检测和定位。利用平均模型,只需要对系统内已有的信号做简单的计算,避免了增加额外的硬件电路和软件负担。此外,误差自适应诊断阈值用于消除死区、延时、采样误差和电感偏差等因素的影响,保证了高鲁棒性和速度。应用该方法,诊断时间最快只需2个开关周期。最后实验结果验证了该方法的有效性。

To fast and accurately diagnose multi-transistor open-circuit faults in three-phase four-wire inverters without adding additional circuits,a method based on the average model and error-adaptive thresholds is presented in this paper.The fault can be detected and located according to the deviations between the average real and expected bridge-arm pole voltages.With the average model,only simple calculations on the existing signals in the system are needed.Therefore,extra circuits and software burden are avoided.Besides,the error-adaptive thresholds are utilized to eliminate the effects of deadtime,delay,sampling error,and inductance deviation,etc.,so that both high robustness and speed can be guaranteed.Using the proposed method,the shortest diagnosis time only requires two switching periods.Finally,experimental results verified the effectiveness of this method.