Zero sequence current-based fault positioning method

Abstract

The invention discloses a fault location method based on zero-sequence current, and aims to provide a fault location method based on zero-sequence current to solve the problem that when a small-current single-phase ground fault occurs in the system, the fault current is very small and the fault signal is weak, causing fault detection, The problem of difficult line selection and positioning includes the following steps: collect the transient zero-sequence current of each detection point on each line at the exit of the busbar, and when the line fails, the transient zero-sequence current changes suddenly; The amplitude of the transient zero-sequence current of each detection point, select at least three lines with the largest transient zero-sequence current amplitude; according to the change of the transient zero-sequence current amplitude of each detection point on the line selected in the step B In case of low current ground fault location. The invention has the advantages that: it overcomes the line without a small current line selection device in the station, can realize on-line monitoring of faults, and find fault locations in time.

Description

technical field [0001] The invention relates to a fault location method, in particular to a fault location method based on zero-sequence current. Background technique [0002] By 2020, the level of intelligent construction and application in central cities (districts) will be greatly improved, the reliability rate of power supply will reach 99.99%, the average annual power outage time of users will not exceed 1 hour, and the quality of power supply will reach the international advanced level; power supply capacity and power supply safety level in urban areas Significantly improved, the power supply reliability rate has reached more than 99.88%, and the average annual power outage time of users does not exceed 10 hours, ensuring the rapid economic and social development of the region; rural and remote areas have comprehensively solved the problem of weak power grids, basically eliminated long-term "low voltage", and distributed transformers per household The capacity is not l...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is that when a small-current single-phase grounding fault occurs in the system, the fault current is very small and the fault signal is weak, which makes fault detection, line selection, and location very difficult. The purpose is to provide fault location based on zero-sequence current method to solve the problem that when a small current single-phase grounding fault occurs in the system, the fault current is very small and the fault signal is weak, which makes fault detection, line selection, and location very difficult