A Faulty Line Selection Method of Distribution Network Based on Fuzzy Cluster Analysis

Abstract

The present invention relates to a fuzzy clustering analysis-based power distribution network fault line selection method. According to the method, the ratio of the variation quantity of the active component of the zero-sequence current of each outgoing line of a power distribution network to the total variation quantity of the active component of the zero-sequence current of the outgoing lines of the power distribution network is calculated; the simulation model of the actual operation of the power distribution network is constructed; and a fault line is determined through using a clustering analysis method. When a single-phase grounding fault occurs on the arc suppression coil grounding system of a neutral point, fault characteristics are not obvious; the grounding mode of the neutral point in the power distribution network is changed, fault signals are amplified, and therefore, line selection accuracy can be improved; a bus-bar potential transformer PT and a current transformer CT are adopted to measure the zero-sequence voltage of a bus-bar and the zero-sequence current of the outgoing lines before and after a resistor is switched; the variation quantity of the active component of the zero-sequence current of each outgoing line of lines is monitored; errors brought by measurement devices such as the current transformer CT of the line can be offset; and high anti-interference performance can be realized.

Description

technical field [0001] The invention relates to a fuzzy clustering line selection method based on zero-sequence current active component variation, in particular to the technical field of a single-phase ground fault grounding line selection method for a small current grounding system. Background technique [0002] The neutral point of my country's 6kV ~ 66kV distribution network is mostly grounded by arc suppression coils. When a single-phase ground fault occurs, it can run with the fault for a period of time. If it is an instantaneous single-phase ground fault, since the inductive current generated by the arc suppression coil and the capacitive current at the fault point are offset, the current at the fault point is maintained at a small value, the purpose of automatic arc suppression can be achieved, and the system can return to normal working state. If a stable power frequency arc is formed at the fault, although the line voltage remains stable, the phase voltage rises, t...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of misjudgment and missed judgment in the fault line selection of the distribution network in the prior art, especially in the event of a high-resistance grounding fault, and proposes a method based on zero-sequence current active component change Quantitative fuzzy clustering method for line selection

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