Analysis and research on a protection dialing code skip of feeder terminal unit

In order to improve the power supply reliability of the distribution network and build a digital distribution network, power supply companies in most provinces have carried out the construction of distribution automation system. The feeder terminal unit (FTU) has relay protection function. The incorrect operation of breaker sometimes caused by the wrong configuration of FTU parameters. The paper analyzes a distribution network failure involving the incorrect operation of the FTU relay protection. Firstly, the process of distribution network fault is introduced. Then, the paper analyzes the results of the accuracy test, protection value analysis, SOE analysis, and device disassembly analysis of the FTU. Finally, the paper provides a detailed analysis of the fault result and proposes rectification suggestions. Through the fault analysis, the paper aims to optimize the parameter configuration of FTU relay protection and improves the reliability of distribution network.