Precise location method for petal-shaped urban power grid ground fault based on multi-line zero-sequence current information

Abstract

The invention relates to a petal type urban power grid grounding fault accurate positioning method based on multi-line zero-sequence current information. Single-phase and two-phase earth fault characteristic analysis is carried out on a petal type urban power grid, and a foundation is laid for simply and effectively realizing accurate positioning of a fault position by utilizing a zero-sequence current association relationship presented by connecting two ends of a trunk line of a single petal ring network to the same bus. Accurate grounding fault positioning can be realized only after the centralized information processing center receives the zero-sequence current steady-state values of the protections on the trunk line, a traveling wave measuring device and the like are not required to beadditionally arranged; and the method has the characteristics of low required communication traffic, low requirement on information synchronism and the like and is reliable in performance, simple andeasy to implement.

Description

technical field [0001] The invention belongs to the field of power system distribution network protection and control. Based on the analysis results of the ground fault characteristics of the petal-type urban power grid, a petal-type urban power grid ground fault accurate positioning method based on the zero-sequence current information of multi-section trunk lines is proposed. Background technique [0002] The urban power grid is directly oriented to power users and undertakes the important responsibility of providing users with high-quality electric energy. It is an indispensable part of the power system. With the rapid development of cities, the density of electricity loads in cities is increasing rapidly, and the requirements for the reliability of urban power supply are gradually increasing. Due to the large range of faults in traditional radial urban power grids, it is increasingly difficult to meet the needs of people's livelihood. Urban power grid wiring The way grad...

AI Technical Summary

Problems solved by technology

However, this method does not consider the impact of load impedance and distributed power. When the load and distributed power are connected to the grid, the zero-sequence impedance of the load and the distributed power step-up transformer will change the magnitude of the zero-sequence current flowing on the line. The accuracy of the fault location method is reduced

In addition, when a ground fault occurs on the main line, the transition resistance between the ground fault point and the ground will amplify the impact of load impedance and distributed power, which greatly reduces the fault location accuracy of this fault location method.

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