一种级联H桥光伏逆变器的开关管故障诊断方法

A Method of Switch Tube Fault Diagnosis for Cascaded H-bridge Photovoltaic Inverter

级联H桥(CHB)光伏并网逆变器广泛应用于大功率、高电压的场合。随着电平数的增多,开关管出现故障的概率也相应提高,因此,有必要研究快速准确的故障诊断方法,为选择合适的容错控制方法提供依据。针对常见的开关管开路故障,提出一种CHB光伏并网逆变器的开路故障诊断方法,该方法利用系统原有的传感器计算故障特征值,并与判据值比较,能够较快得出故障开关管位置。实验结果证明了所提方法的有效性。

Cascaded H-bridge(CHB)photovoltaic grid-connected inverter is widely used in high-power,high-voltage occasions.With the increase of the number of levels,the probability of the failure of the switch tube is also increased accordingly.Therefore,it is necessary to study the fast and accurate fault diagnosis method to provide the basis for selecting the appropriate fault-tolerant control method.Aiming at the common open circuit fault of the switch tube,a method of open circuit fault diagnosis for CHB photovoltaic grid-connected inverter is proposed.This method uses the original sensor of the system to calculate the fault eigenvalue,and compared with the criterion value,then it can get the fault switch tube position quickly.The experimental results show the effectiveness of the proposed method.