A single-phase ground fault line selection and location method for distribution network master station

Abstract

The present invention discloses a distribution network master station single-phase earth fault line selection location method. After distribution network master station receives fault indicator telecommand, anti-misinformation criterion is started to perform start a line selection location program for real faults. The line selection location method comprises the steps of: combining a zero sequencecurrent, combining three-phase electric field effective value change and the zero sequence current mutation to determine a fault starting point, and employing a band-pass filter to obtain transient state zero sequence currents after fault; sorting the transient state zero sequence current effective values of each fault indicator at the starting end of each line from big to small, calculating correlation coefficients of the transient state zero sequence currents between the devices at the starting ends of each two lines to obtain fault line selection results, and finally, determining fault positions in the fault lines. The distribution network master station single-phase earth fault line selection location method can eliminate misinformation when faults are not generated, cannot be influenced by a neutral point grounding mode and a single-phase earth fault mode, and is reliable and accurate in line selection location effect.

Description

technical field [0001] The invention relates to a line selection and positioning method for a single-phase grounding fault of a distribution network main station, in particular to a line selection and positioning method for a single-phase grounding fault of a distribution network main station based on a transient wave recording type fault indicator. Background technique [0002] my country's distribution network widely adopts the non-effective neutral point grounding operation mode, mainly because the neutral point is not grounded or grounded through the arc suppression coil. When a single-phase ground fault occurs, since the line voltage remains symmetrical, it is generally allowed to continue running for 1-2h. However, in order to prevent the fault from expanding due to the increase of the phase voltage, the line should be selected quickly and the fault is located. [0003] The current problems in fault line selection and location are: (1) There are frequent and general fa...

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Problems solved by technology

[0003] The current problems in fault line selection and location are: (1) There are frequent and general false alarms in the fault indicator of transient state recording type. In order to ensure the effective monitoring of the operation of the distribution network, it is necessary to increase the screening of reported faults ; (2) Due to the existence of sampling errors and the fact that the fault characteristics may not be obvious, it is impossible to select and locate the line in time and accurately