Location method of small current ground fault section in distribution network based on maximum mean difference

Abstract

The invention discloses a method and system for locating a small current grounding fault section of a distribution network based on the maximum mean value difference, and belongs to the field of fault location of a distribution network. The method includes: when a single-phase ground fault occurs in the system, determine the fault line; calculate the maximum mean discrepancy (MMD) value between the double-terminal zero-mode currents of each section of the fault line, and use the section with the largest MMD as the fault section; The two-terminal zero-mode current of each section is collected at the same time. The method of the present invention is applicable to the positioning problem of the distribution network fault section where the neutral point is grounded with a small current, and can effectively solve the problem that there is zero-mode current similarity characteristic distortion in the positioning blind area of ​​the distribution network line, resulting in an error in the positioning section. The fault section can be accurately located in the fault scenario, and it has certain robustness, so it can be used as an important part of the distribution automation system.

Description

technical field [0001] The invention belongs to the field of distribution network fault location, and more specifically relates to a method and system for locating a small-current grounding fault section of a distribution network with maximum mean value difference. Background technique [0002] Single-phase-to-ground faults occur frequently in the distribution network, and a fast and accurate fault location method is the basis for realizing distribution network automation. Usually, after a single-phase-to-ground fault occurs, the double-terminal zero-mode current waveforms in the fault zone have a low similarity and opposite polarity, while the double-terminal zero-mode current waveforms in the non-fault zone have a high similarity and the same polarity. However, due to the complex structure of the distribution network and the prevalence of overhead-cable mixed lines, when a single-phase ground fault occurs in some parts of the line, the above-mentioned zero-mode current wav...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above defects or improvement needs of the prior art, the present invention provides a method and system for locating the small current ground fault section of the distribution network with the largest mean value difference. Distortion of characteristic characteristics leads to the problem of wrong positioning section, correctly locate the faulty section, and improve power supply reliability

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