Single-phase earth fault line discrimination method based on transient direction of zero-sequence fault component

Abstract

The invention provides a single-phase grounding fault line discrimination method based on the transient direction of a zero-sequence fault component, and solves a problem that a conventional small-current grounding single-phase fault line discrimination method is poor in accuracy and reliability, and the method comprises the steps: firstly collecting the zero-sequence voltage of a to-be-discriminated small-current grounding system and the zero-sequence current of each outgoing line; then carrying out wavelet transformation, denoising and inverse transformation reconstruction in sequence, solving zero-sequence current integral values of all outgoing line currents, judging a single-phase earth fault line according to the positive and negative polarities of the zero-sequence currents, carrying out zero-sequence data collection before judgment, removing interference of noise on zero-sequence fault component signals through the denoising process, and obtaining a single-phase earth fault line. The method guarantees the accuracy of the reserved semaphore, improves the discrimination accuracy and sensitivity of a single-phase grounding fault line, is of guiding significance to the subsequent work of a worker, and does not need to specially install discrimination equipment.

Description

technical field [0001] The present invention relates to the technical field of single-phase ground fault line identification, and more specifically, relates to a single-phase ground fault line identification method based on the transient direction of zero-sequence fault components. Background technique [0002] In my country's 35kV and below power systems, the neutral point non-direct grounding method is generally used. For the power system with the neutral point grounded through a small resistance, it is easier to judge because the fault zero-sequence current is relatively large. Sequence protection can realize the discrimination of the ground fault line. For the power system in which the neutral point is not grounded and the neutral point is grounded through the arc suppression coil, the current flowing through the ground point when a ground fault occurs is small, so it is also called It is a small current grounding system. [0003] According to the fault statistics report ...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem of poor accuracy and reliability of the existing low-current grounding single-phase fault line identification method, the present invention proposes a single-phase grounding fault line identification method based on the transient direction of the zero-sequence fault component to improve the accuracy of single-phase grounding fault line identification sex and sensitivity

Images