Distributed single-phase earth fault ranging system and ranging method thereof

Abstract

The invention relates to a distributed single-phase earth fault ranging system that is used for realizing ranging of a fault on a high tension transmission line between two transformer substations. The system comprises: at least two sets of fault current detection device sets, which are installed at preset test points of a high tension transmission line; a remote wireless communication module; and a remote monitoring master station. The remote monitoring master station is respectively connected with the fault current detection device sets by the remote wireless communication module as well as receives fault currents collected by the fault current detection device sets by the remote wireless communication module; and the remote monitoring master station carries out comparison and an analysis according to positional data of the preset test points and length data of the high tension transmission line, so that a final fault position is obtained. In addition, a ranging method of the distributed single-phase earth fault ranging system is also provided. Power frequency fault current information and fault current travelling wave energy information are utilized to determine fault intervals; and different positioning equations are selected according to different fault intervals as well as fault point positions are determined; therefore, a dead zone problem can be solved, wherein the problem occurs when there are faults at a head and an end of a line, that is, when a fault point approaches a bus.

Description

technical field [0001] The invention relates to the technical field of transmission line fault distance measurement, in particular to a distributed single-phase ground fault distance measurement system and a distance measurement method based on comprehensive analysis of fault current information. Background technique [0002] The failure of the transmission line will not only reduce the reliability of the system power supply, but also seriously affect the stability of the system operation, causing heavy losses. There have been many cases of power grid collapse accidents caused by transmission line failures at home and abroad. According to the statistics of various faults, the number of single-phase ground faults accounts for almost 90% of all fault types. Therefore, the distance measurement method for single-phase ground faults is studied to quickly, reliably and accurately locate faults, and timely discover and deal with hidden dangers of insulation. The reliability and he...

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Problems solved by technology

[0030] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a distributed single-phase ground fault ranging system and its ranging method to improve ranging accuracy, and solve the problem of transformer bandwidth limitation and Based on the problem of uncertain wave speed, avoid the dead zone problem when the fault point is close to the busbar

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