UPS系统中电压型逆变器开路故障诊断研究

逆变器开路故障是不间断电源(Uninterruptible Power Supply, UPS)系统中一种常见故障，它会降低电能质量，甚至会引起其他部件的潜在二次故障。研究有效的逆变器故障诊断技术对提高UPS系统的可靠性具有重要意义。因此，采用基于绝对归一化的Park矢量法实现逆变器开路故障诊断。利用相电流的平均值与相电流绝对值的平均值的归一化量诊断和定位单个或两个开关管开路故障。利用相电流绝对值的平均值与Park矢量模的归一化量诊断同一桥臂的两个开关管开路故障，该方法可以有效地实现开路故障检测和故障定位。最后基于Matlab/Simulink对提出的故障诊断方法进行验证，仿真结果表明了所提出故障诊断方法的有效性。

Open-circuit fault diagnosis of a voltage-source inverter in a UPS system

The open-circuit fault in an inverter is a common fault in an Uninterruptible Power Supply (UPS) system. It can reduce power quality and even cause potential secondary faults in other components. It is of great significance to study effective fault diagnosis technology of inverters to help improve the reliability of a UPS system. Therefore, the Park vector method based on absolute normalization is used for open-circuit fault detection of the inverter. The normalized value between the average value of phase current and the average value of the absolute value of phase current is used to diagnose and locate an open-circuit fault of a single or two switches. The normalized value between the average value of the absolute value of phase current and the Park vector module is used to diagnose the open-circuit fault of two switches of the same bridge arm. This method can effectively realize fault detection and fault location. Finally, the proposed fault diagnosis method is verified using Matlab/Simulink. The simulation results show the effectiveness of the proposed fault diagnosis method.This work is supported by National Natural Science Foundation of China (No. 51507002) and Science and Technology Project of Guangxi Power Grid Co., Ltd. (No. GXKJXM20180433).