Method for grounding and selecting lines of low-current grounding system and device

Abstract

The invention discloses a method for grounding and selecting lines of a low-current grounding system. The method comprises the following steps of: carrying out continuous real-time sampling on zero-sequence voltage and zero-sequence current signals, obtaining sampling data and caching the sampling data; calculating the sampling data, obtaining an effective value in set time interval of the signal, and comparing the effective value with the preset threshold value; when the effective value is larger than or equal to the threshold value, determining a fault starting point, taking the fault starting point as the reference time, analyzing and calculating the sampling data which contains the reference time, and is cached in the time interval with preset length, and determining the line with single-phase grounding fault. The invention also discloses a device for grounding and selecting lines of the low-current grounding system. The invention solves the problem of selection missing and selection error because complete temporal data during the occurrence of fault is difficult to obtain by the prior art, improves the accuracy of temporal line selection and has higher credibility of detection results.

Description

technical field [0001] The invention relates to control technology, in particular to a method and device for grounding line selection of a small current grounding system. Background technique [0002] During the working process of the power system, due to various reasons, sometimes a single-phase short-circuit fault occurs between the power line and the ground, resulting in a grounding phenomenon. This short-circuit fault is usually called a single-phase ground fault. Since a single-phase ground fault is a serious safety hazard and may lead to serious consequences, in order to ensure the safe and normal operation of the power system, it is necessary to detect the power system with a single-phase ground fault in time to confirm the occurrence of a single-phase ground fault. Specific lines and corresponding processing. [0003] The method for detecting and confirming a specific line where a single-phase ground fault occurs is generally called a grounding line selection method...

AI Technical Summary

Problems solved by technology

Therefore, using the existing transient line selection method, even if the moment when the single-phase-to-ground fault occurs is not missed, it is often impossible to obtain relatively complete sample data of the fault power signal after the single-phase-to-ground fault occurs. Reduced, prone to missing and wrong selection

[0008] To sum up, the existing transient line selection method has poor real-time performance, which can easily lead to missed and wrong selection.

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