Single-phase ground fault section localization method for small current system based on transient information fusion

Distribution network most often occurs single-phase ground fault phenomenon, accurate and rapid location of distribution network in the occurrence of single-phase ground fault section, to improve the security and reliability of the distribution network is of great significance.However, with the increasing complexity of distribution lines, when a single-phase grounding fault occurs, the existing methods are unable to locate and troubleshooting the faulted section within a short period of time, accordingly, a single-phase grounding fault section localization method based on the fusion of transient information for small-current systems is proposed.Judge whether a single-phase grounding fault occurs by whether the zero-sequence voltage crosses the limit, collect the transient signal after a single-phase grounding occurs on the line through the feeder terminal controller, and fuse the transient zero-sequence current harmonic phase angle, transient zero-sequence current, and transient power to make an in-situ judgement on the upstream and downstream of faults in each section.The transient fusion criterion determines the specific fault location upstream of the fault, determines the grounding mode according to the zero-sequence current fundamental phase angle and introduces a control coefficient to make fault localization more targeted. Finally. The simulation results by building 10kV distribution network show that the method is not affected by the grounding resistance and the initial phase angle of the fault in the small-current grounding system, and it can still accurately determine the fault zone in the case of the existence of multi-branch lines in the distribution network.