Single-phase earth fault location method and system applied to power distribution network

Abstract

The present invention provides a single-phase earth fault location method and system applied to a power distribution network. The method comprises the steps of: determining whether single-phase earthfaults are generated or not according to change of zero sequence voltages of sectionalized busbars, when the zero sequence voltages are larger than a preset threshold value, connecting with a neutral-point earthing resistor of an earthing transformer, generating a large current by a fault loop, allowing electrical quantity feature information related to the fault lines to be changed, synchronouslycollecting electrical quantity feature information of each sectionalized busbar and each section of a transmission line and uploading the electrical quantity feature information to an intelligent protection control host by an intelligent collection control device, determining whether the electrical quantity feature information related to the fault line meets a differential protection motion condition or not by the intelligent protection control host so as to locate the fault lines. The single-phase earth fault location method can automatically, intelligently and rapidly locate the single-phase earth faults and can achieve rapid isolation for the fault lines so as to reduce the operation workload of a power distribution network and improve the power supply reliability of the power distribution network.

Description

technical field [0001] The invention relates to the technical field of power distribution, in particular to a single-phase ground fault location method and system applied to a power distribution network. Background technique [0002] The domestic 10kV distribution network usually operates in an ungrounded neutral point. In this mode of operation, when a single-phase ground fault occurs in the distribution network, the lines in the distribution network will not form a short-circuit loop, and the fault point only forms a loop with the distributed capacitance of the line, and the fault current generated is too small to automatically Start the protection action. However, when a single-phase ground fault occurs, the ground voltage of the non-faulted phase increases. In this case, if the fault location is not determined in time to eliminate the fault, the long-term high voltage will damage the insulation performance of the grid equipment. Seriously endanger the safe operation of...

AI Technical Summary

Problems solved by technology

[0005] This application provides a method and system for locating a single-phase ground fault applied to a distribution network to solve the problems in the prior art of locating a single-phase ground fault line by manual line selection, which takes a long time and cannot quickly locate the fault location , and problems affecting applications that normally line

Images