Single-Phase Grounding Fault Line Selection Method of Active Distribution Network Based on Swept Frequency Injection Signal

Abstract

The power industry is the support of the national economy. With the continuous development of my country’s economy, the requirements for the stability of the power system are also increasing, and the massive access of new energy sources further increases the difficulty of selecting faulty lines in the distribution network. This paper uses the new energy power generation device itself to solve this problem, and proposes a single-phase grounding fault line selection method for active distribution network based on swept frequency injection signal. When a single-phase fault occurs, the inverter’s modulation strategy is changed to inject high-frequency characteristic signals into the distribution network for a short time. The feeder terminal of the distribution network completes the selection of the faulty line by analyzing the zero-sequence current of the injected signal. Based on this, a typical active distribution network simulation model is established, and the fault characteristics of different ground resistances at different locations are analyzed. It is proved that the new method is more effective than the traditional method of signal injection and can improve the accuracy of line selection.