A Reclosing Criterion System for Ground-to-Ground Short-circuit Faults of Hybrid Transmission Lines

Abstract

The invention provides a reclosing criterion system for an overhead line and cable hybrid transmission line to ground short circuit fault. The system comprises a field monitoring unit and an analyzing and processing unit, wherein the field monitoring unit performs on-line collection of hybrid circuit signals of the cable body at the cable terminal of the hybrid transmission line and the terminal ground lead, the collected analog signals are sent to the analyzing and processing unit after being transferred and processed so as to analyze and process current values at the two ends of each phases of the cable, and whether the line to ground short circuit fault occurs on the cable line segment is judged. The system has the advantages that according to operation conditions of different ground connection manners of the cable line, the influence on the hybrid line of the overhead line fault and the electric cable fault and the fault features is analyzed, and the current change rules of the cable body and the ground lead of the hybrid line during occurring of the fault are measured and calculated, and the combination of influence on the short circuit fault and the hybrid line of the electric cable and the fault features provides the theory reference for intelligently judging the fault point position and deciding whether to perform the reclosing operation.

Description

technical field [0001] The invention relates to a criterion system, in particular to a reclosing criterion system for a hybrid transmission line short-circuit fault to ground. Background technique [0002] For the hybrid lines of overhead lines and power cables in power transmission lines, especially the hybrid lines in the form of overhead lines-cable-overhead lines, overhead lines-cables and cables-overhead lines, due to the existence of power cable lines, when hybrid lines appear When a short-circuit fault to ground causes a trip, whether the reclosing operation can be performed needs to be carefully judged. Because if the short-circuit fault to ground occurs on the cable line, the reclosing operation of the relay protection system will expand the fault accident on the cable line, cause damage to the cable line, and even cause fire and other safe operation accidents. It has happened many times in China on hybrid lines because the reclosing operation was performed without...

AI Technical Summary

Problems solved by technology

Because if the short-circuit fault to ground occurs on the cable line, the reclosing operation of the relay protection system will expand the fault accident on the cable line, cause damage to the cable line, and even cause fire and other safe operation accidents.

It has happened many times in China on hybrid lines because the reclosing operation was performed without judging whether the short-circuit fault point to the ground occurred on the cable line, resulting in damage to the cable line joints, deterioration of cable stress distribution, and even fires that caused the entire cable channel to fail. Instances of burning down, causing extensive property damage and power outages

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