Research On Single-phase To Ground Fault Location Method In Distribution Networks

The location of single-phase to ground fault in distribution network is the emphasis and difficulty of the procedure of implementing distribution automation. Among the common faults of distribution networks, single phase to ground fault appears with largest probability. The rapid and correct locating of fault point, the timely isolating of fault and resume of power supply, are all meaningful and valuable for increasing the reliability of the power supply.This paper mainly bases on the operation of distribution automation. When fault in the line appears, the data of single-phase to ground fault is collected by feeder terminal units (FTU), and then uploaded to the main station, which deals with the data synthetically. Through the analysis of the influence factor of the distance measuring, the location method which locates the fault section first and then measures distance precisely was presented. Classifier is to be designed to locate fault section. Energy value of every section's zero-sequence current is to be taken as recognition clues. The location of fault point is to be confirmed between two switches, which will benefit the sudden isolation of fault section. Distance measuring arithmetic corresponds to various section of fault, constructs different fault distance measuring sub-model, and extracts the transient characteristic quantity of zero-sequence currents signal around the fault points, meanwhile, it makes use of support vector machine to form mapping from eigenvector to distance plane. The result of simulation and analysis prove that the method which is brought up in this paper can realize single-phase to ground fault system's section location and distance measuring in distribution networks.