Distributed fault line selection method

Abstract

The invention relates to a distributed fault line selection method, and the method comprises the steps: monitoring phase current data in real time through a phase current collection device, and storing the phase current waveform data collected in real time; monitoring PT-side secondary opening triangular voltage in real time through a zero-voltage monitoring device to obtain zero-sequence voltage,and directly transmitting waveform to a line selection judgment device; and the line selection judgment device performing waveform identification and judgment on the uploaded disturbance waveform inthe fault duration to finally obtain whether a grounding fault occurs or not, and outputting a judgment result and a fault positioning result. Therefore, by adopting a mode of installing the synchronous zero-sequence voltage monitoring device in the substation and installing the synchronous current acquisition device at the head end of the overhead line, a solution of matching inside and outside the substation is realized, and the practical problems that a traditional low-current device is completely installed in the substation, needs to be installed in a power-off mode and is high in installation and maintenance difficulty are effectively solved. An algorithm combining zero-sequence voltage amplitude absolute change and relative change is adopted.

Description

technical field [0001] The invention relates to a fault line selection method, in particular to a distributed fault line selection method. Background technique [0002] As far as the existing lines are concerned, especially the overhead lines, the distribution lines have many branches, long lines, and complex topologies. When a short circuit or ground fault occurs, the fault must be isolated and eliminated as soon as possible, otherwise it will seriously affect the quality and efficiency of power supply, and even bring about power supply safety problems. For this reason, once a single-phase ground fault occurs on a medium-voltage distribution line, it is necessary to find out the fault line and fault point as soon as possible to isolate the fault. The traditional method is to judge whether a single-phase ground fault occurs by detecting the value of the zero-sequence voltage on the substation bus. If a ground fault occurs, the method of manually pulling the switch line by ...

AI Technical Summary

Problems solved by technology

However, due to the difficulty of installation, relying on substation zero-sequence CT, it is only installed at the very head of the outgoing line, and the judgment principle cannot adapt to various environments and other factors. The actual operation effect is not good, causing many users to stop using it.

[0004] Moreover, the traditional line selection device installed in the substation can only select the main line where the fault is located, but cannot further locate the section or branch line where it is located, so it is impossible to achieve "quick and nearby isolation"

[0005] The original traditional line selection device can only be installed at the first section of the line in the substation, and cannot obtain branch line information, so this function cannot be realized;

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