The Research Of Earth Fault Detection In Small Current Grounding Network Based On Multi-criteria Fusion Strategy

Grid leakage protection is an important content of the relay protection, especially the small current grounding system leakage protection is always an important part of the study for electric power system. Previous single line selection method has some limitations and applicability, and the fault line is not used for the benefit of fault line selection information, so the sensitivity and reliability of faulty line selection is not high. Through the analysis of existing leakage protection plan, this paper proposed new method which base on fuzzy set theory, this is a method which introduce and apply the fuzzy set theory in faulty line detection for this paper to intelligently fuse different kinds of the fault information, forming a multiple criteria fusion line selection method.This article mainly analyzes the zero sequence current based on the artificial neutral point earthed differential leakage protection theory at the first half of the paper. And proves the feasibility of the theory using MATALB software make the simulation; in the lower half, this theory was applied in actual system, make the system hardware based on the TMS320F2812 controller, and synchronous sampling chip MAX1308 to ensure the data collecting synchronization. And the part of the software are described in detail. To verify the accuracy and reliability of the line selection method under laboratory conditions by building a power system fault line selection experiments carried leakage.