Power distribution network single-phase earth fault section locating method based on correlation analysis

Abstract

The invention provides a power distribution network single-phase earth fault section locating method based on correlation analysis. The fault line selection problem in the single-phase earth fault process of a power distribution network is not solved well, and fault locating is more difficult to refer to. After a single-phase earth fault happens to a system, the first capacitive frequency band concept is utilized, each line is simplified into a capacitance model in a zero-sequence network under the selected frequency band, earth fault detection devices are arranged on line outlets and branches to measure zero-sequence voltages and zero-sequence currents, association coefficients of zero-sequence voltage differentials and the zero-sequence currents are obtained, whether fault points are in the section or not is judged according to plus and minus of the obtained association coefficients, finally the association coefficients are judged and calculated to be minus, and the section farthest away from a bus is the section where the fault points are located. The method is simple in principle and easy to implement, fault section locating can be carried out fast and reliably, and the method can be used for neutral ungrounding power distribution systems and can be used for power distribution systems with neutral points grounded through arc suppression coils.

Description

technical field [0001] The invention relates to a method for locating a fault section in a power system, in particular to a method for locating a single-phase ground fault section in a distribution network based on correlation analysis. Background technique [0002] The distribution network is directly connected to users, and its reliability largely determines the power supply quality of the power system. Improving the power supply reliability of the distribution network is an important research content to improve the power supply reliability of the power system. Traditional distribution network lines mostly adopt radiation power supply mode, there are no circuit breakers and control equipment at the branch points, and it takes a long time to restore power supply, which affects the reliability of distribution network power supply. In recent years, with the development of smart grid, "self-healing" will become the basic function of the grid, and the location of the fault sec...

AI Technical Summary

Problems solved by technology

[0003] Most of my country's distribution network adopts the neutral point small current grounding method. Affected by the neutral point grounding method, distribution network scale, transition resistance and other factors, the problem of fault line selection has not been satisfactorily resolved, let alone section positioning.

Based on the above factors, it can be seen that the line selection problem of the small current grounding system has not been solved well, and the research results of section positioning are even more difficult to talk about.

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