Small-current grounding fault line selection device-based power distribution network grounding fault location method

Abstract

The present invention belongs to the power system power distribution network single-phase grounding fault detection technical field and relates to a small-current grounding fault line selection device-based power distribution network grounding fault location method. The method specifically includes the following steps that: (1) a small-current grounding fault line selection device acquires bus-bar zero-sequence voltage and the zero-sequence current of the head end of each line at a fault time point; (2) a fault indicator acquires fault current peak signals and zero-sequence current signals at the fault time point; (3) the small-current grounding fault line selection device selects a fault line; (4) the small-current grounding fault line selection device collects characteristic signals acquired by the fault indicator on the fault line; and (5) and single-phase grounding fault location judgment is performed. With the method of the invention adopted, the single-phase grounding fault of a power distribution network can be accurately located; and the small-current grounding fault line selection device applies transient signal characteristic frequency band line selection theory, and therefore, the line selection accuracy of the small-current grounding fault line selection device can be higher than 98%, and transient signals can be accurately captured, fault analysis and traceability can be realized, and load on-line measurement, statistics and analysis are supported.

Description

technical field [0001] The invention relates to the technical field of single-phase ground fault detection in a distribution network of a power system, in particular to a method for locating a ground fault in a distribution network based on a small current grounding line selection device. Background technique [0002] With the continuous increase of electricity demand, the lines of the distribution network with a voltage level of 35kV and below are getting longer and longer, with more and more branch lines, the network structure is becoming more and more complex, and the line failure rate is also relatively high, which has become an impact on the power supply network. The central question of reliability. Although the microcomputer relay protection device can detect and cut off the short-circuit fault, and the new generation of small current grounding line selection device represented by the principle of transient state can detect and cut off the grounding fault, but at prese...

AI Technical Summary

Problems solved by technology

Although the microcomputer relay protection device can detect and cut off the short-circuit fault, and the new generation of small current grounding line selection device represented by the principle of transient state can detect and cut off the grounding fault, but at present, only the fault line can be located, and it is not possible to accurately locate it. point of failure

[0003] At present, the location of fault points basically requires manual on-site search, which often consumes a lot of manpower, material resources and time, and directly affects the reliable power supply capacity and power supply quality of the distribution network.

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