Method and system for locating short-circuit fault of high-voltage single-core cable

Abstract

The invention relates to a method and system for locating a short-circuit fault of a high-voltage single-core cable. The method comprises the steps that leakage current reflected wave signals at the head end and / or the tail end of the cable to be tested with direct current voltage applied to the two ends are collected; the leakage current reflected wave signals at the head end and / or the tail endof the cable to be tested are identified to obtain the arrival time of the leakage current reflected wave signals at the head end and / or the tail end of the cable to be tested; and according to the arrival time of leakage current reflected wave signals at the head end and / or the tail end of the cable to be tested, the distance between a fault point and the head end and / or the tail end of the cableto be tested is calculated to determine the position of the fault point. According to the method and system, the direct current voltage is applied to the cable to be tested, the leakage current reflected wave signals of the cable to be tested are measured, and the arrival time of the leakage current reflected wave signals is calculated, so that the position of the fault point is further obtained,the accurate positioning of the fault point is realized, the safety is high, the method and system are not influenced by grounding resistance, the line impedance of the cable to be tested is not required, and the application range is wider.

Description

technical field [0001] The invention relates to the technical field of cable fault measurement, in particular to a short-circuit fault location method and system for a high-voltage single-core cable. Background technique [0002] The current off-line fault location methods for high-voltage single-core cables are mainly divided into two types based on the measurement principle: 1) Impedance method. By testing the line impedance of the faulty cable from the measuring end to the fault point, short-circuit the core of the cable under test and the metal sheath, and calculate the fault distance according to the impedance per unit length, or test the faulty section and the full-length section of the cable The ratio of the voltage drop, and then multiplied by the total length to calculate the fault distance. Impedance method is generally used to test the fault distance of cables whose insulation resistance at the fault point is within 10kΩ, and the measurement error is relatively l...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that there is a direct electrical connection between the distance measuring instrument and the high voltage part during the test, the safety is poor, and the technical parameters of the test equipment are high.

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