Line selection zero-sequence current polarity detection and automatic correction method

Abstract

The invention discloses a line selection zero-sequence current polarity detection and automatic correction method. A low-current grounding line selection device and a zero-sequence current transformerare wired; the low-current grounding line selection device collects amplitudes and phases of self-checking voltage and self-checking current through a self-checking voltage input terminal and a self-checking current input terminal, compares phase differences of the self-checking voltage and the self-checking current, and determines that wiring is correct if the phase differences are close to 0 degree; and if the phase difference is about 180 degrees, it is judged that the wiring is wrong, and correction is performed after judging that the wiring is wrong; the correction marks of all access lines are initialized to be 0, exclusive-OR operation is performed on the correction marks of all wrong access lines and 1 to obtain new correction marks, phase correction is performed on all wrong access lines, specifically, the correction marks of all wrong access lines are multiplied by a correction angle 180 to carry out correction, and the correction result is memorized. According to the method, the polarity state of the zero sequence mutual inductor can be rapidly detected, and the reversely connected line can be automatically corrected.

Description

technical field [0001] The invention belongs to the technical field of single-phase grounding protection and protection, and in particular relates to a method for detecting and automatically correcting the polarity of a line selection zero-sequence current. Background technique [0002] When a single-phase ground fault occurs in a low-current grounding system, the fault current is relatively small, and it can operate with the fault for a period of time, but the single-phase ground fault is likely to cause the normal phase voltage to rise, which may lead to insulation breakdown and cause faults. Therefore, when a single-phase ground fault occurs, the faulty line must be quickly detected and eliminated. [0003] The existing line selection algorithm has requirements for the phase of zero-sequence voltage and zero-sequence current, so the wiring needs to be correct. However, the existing line selection devices generally have a large number of lines, and the positions of the wi...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems existing in the above-mentioned prior art, the present invention provides a method for detecting and automatically correcting the polarity of the zero-sequence current in line selection, which can quickly detect the polarity state of the zero-sequence transformer, and can automatically correct the reversed circuit It can effectively avoid time-consuming and labor-intensive situations in the process of manual line checking and line adjustment

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