Diagnosis method for fault in intersected interconnection box based on grounding current

Abstract

The invention discloses a diagnosis method for a fault in an intersected interconnection box based on grounding current. The method is implemented by a device comprising a data collection unit, a current coefficient K computation unit, an unbalanced coefficient J computation unit and a diagnosis parameter K and J based comprehensive fault type acquisition unit. The data collection unit is composed of a grounding current collection unit, a grounding current band-pass filtering unit and an information recording unit. The data coefficient K computation unit is composed of a current data information storage unit and a current coefficient computation unit. The unbalanced coefficient J computation unit is composed of a current coefficient storage unit and an unbalanced coefficient computation unit. The diagnosis parameter K and J based comprehensive fault type acquisition unit is composed of a parameter table unit consisting of normal operation condition values and faulty values of diagnosis parameters K and J, and a unit for comprehensively judging specific fault type. According to the diagnosis method for the fault in the intersected interconnection box based on grounding current provided by the invention, the purpose of effectively diagnosing the three typical faults in the intersected interconnection box is achieved; and the diagnosis method has small external interference and low cost, can be well applicable to circuits in different voltage levels, and can be popularized to the multiloop long circuit.

Description

technical field [0001] The invention relates to the field of fault detection in cross-connection grounding lines of metal sheaths of power cables, in particular to a fault diagnosis method in cross-connection boxes based on grounding current. Background technique [0002] With the acceleration of urbanization in my country, the negative demand for electricity has increased sharply. More and more power cables are being laid in the underground power grid, and the cable lines are becoming longer and longer. In order to effectively reduce the sheath circulation, the current long cable lines are Use a cross interconnection grounding system. [0003] The cross-connection box in the line is prone to failures caused by natural or human factors. According to the statistics of fault cases in Guangzhou, the faults in the cross-connection box account for more than half of the total number of cross-connection line faults every year, such as wiring errors in the cross-connection box, coaxi...

AI Technical Summary

Problems solved by technology

At present, many studies focus on the online monitoring system. Through online monitoring of circulating current and induced voltage, a set of measures to grasp the operation of the entire cross-connection line is proposed. However, the size of the circulating current is affected by factors such as grounding resistance, load current, and laying method. The reliability of the monitoring device is unstable and susceptible to external interference, and the installation of the entire line is a bit complicated, and the cost of the line is relatively high

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