High-resistance grounding fault identifying and positioning method based on fault information

Abstract

The invention discloses a high-resistance grounding fault identifying and positioning method based on fault information. The method comprises the following steps of (1), after a fault is caused, reading fault wave-recording images of a fault line, a bus and adjacent lines which are electrically associated with the fault line through a grid fault wave recorder networking system ; (2) analyzing the fault wave-recording images to obtain the main fault characteristic of a grid when an electric transmission line has the fault, and carefully analyzing the wave-recording images on the two sides of the fault line to judge whether a voltage and current phasor identifying line has a high-resistance grounding fault or not before and after the fault is caused; (3) according to the zero-sequence differential protection principle, identifying the line with the high-resistance grounding fault; and (4) based on fault wave-recording information and a network topology structure, according to the grid fault sequence network analyzing principle, calculating a fault point position and grounding resistor high-resistance value by using 'a distributed relay protection and calculation system'.

Description

technical field [0001] The invention relates to the technical field of fault identification and fault location of power system grids, in particular to a high-resistance ground fault identification and location method based on fault information. Background technique [0002] In high-voltage transmission lines, single-phase ground faults are the most common faults. Single-phase ground faults sometimes pass through high transition resistance and are accompanied by arcs, which have the characteristics of small fault current mutations, unstable current levels, and presence of harmonics and high-frequency components. Fault characteristics that are not conducive to the reliable detection of protection, causing two sets of main protection to operate successively instead of simultaneously, or one set of main protection is activated while the other is not, or even the main protection does not move and the backup protection operates and other complex phenomena. therefore, [0003] 1....

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Problems solved by technology

[0005] 3. At present, most line protection and fault recorders use the ranging algorithm based on the principle of impedance measurement. This algorithm is greatly affected by factors such as fault type, fault resistance, and load impedance at the opposite end of the line. The distance result will seriously deviate from the real fault distance, which cannot meet the application requirements of the site

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