Power distribution network grounding line selection method and system based on multi-measuring point and fault vertical characteristic

Abstract

The invention discloses a power distribution network grounding line selection method and system based on multi-measuring point and fault vertical characteristics; the line selection method verticallycompares fault characteristics of different positions along the line, uses a fuzzy theory to determine a membership function, converts complex fault criteria considering multi-terminal data into eachline fault support degree, uses a heredity algorithm to determine a membership function parameter, and calculates the line fault membership so as to determine a fault line, thus obtaining a line selection result. A conventional method depends on each line fault zero sequence current; the power distribution network grounding line selection method can solve said problems, can expand data sources, can improve data fault tolerance, and is suitable for multi-fault grounding conditions including an arc extinguishing coil grounding system, thus improving undercurrent earth fault line selection accuracy and applicability.

Description

technical field [0001] The invention relates to the technical field of distribution network fault line selection, in particular to a distribution network grounding line selection method and system based on multiple measurement points and fault longitudinal characteristics. Background technique [0002] In order to solve the problem of single-phase ground fault line selection in small current grounding systems, experts and scholars have proposed a variety of fault line selection methods. The existing methods for line selection for small current grounding faults include: fundamental wave group ratio amplitude ratio method, fifth harmonic method, first half wave method, active component method, transient zero-mode characteristic method, wavelet transform method, signal injection method wait. However, due to the diversity of neutral point operation modes and ground faults, the accuracy and adaptability of these traditional single line selection methods cannot meet the requireme...

AI Technical Summary

Problems solved by technology

Take the 110kV / 10kV substation system with three outgoing lines equipped with new fault indicators as an example. When a single-phase ground fault occurs, a zero-sequence voltage source appears at the fault point, and the zero-sequence current flows from the fault point to the bus and is shunted to the The non-fault line flows into the ground through the ground capacitance of the non-fault line. In theory, the fault zero-sequence current characteristics of the single-phase ground fault can be used to accurately select the fault line, but in practice, due to the weak fault current and the neutral point It is difficult to accurately analyze and describe the relationship between grounding mode, fault resistance and arc, fault information and fault line with existing power system theory

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