High-voltage single-core power cable partial discharge online monitoring method and system

Abstract

The invention relates to a high-voltage single-core power cable partial discharge online monitoring method. A first high-frequency current sensor, a second high-frequency current sensor, a third high-frequency current sensor and a fourth high-frequency current sensor are disposed sequentially on a power cable, and the four high-frequency current sensors collect pulse interference signals in the power cable; the pulse interference signals collected by the four high-frequency current sensors are transmitted to a detection unit, and the detection unit carries out digital processing of the pulse interference signals transmitted by the four high-frequency signal sensors respectively; and the detection unit transmits the signals after digital processing to a test host, and the test host carries out a comparative analysis of pulse times between the first high-frequency current sensor and the second high-frequency current sensor and between the third high-frequency current sensor and the fourth high-frequency current sensor, determines the discharge position of the power cable based on the comparative analysis results, and stores and displays the discharge position information of the power cable.

Description

technical field [0001] The invention relates to an insulation testing technology and system for electric equipment, in particular to an on-line monitoring method and system for partial discharge of a high-voltage single-core power cable. Background technique [0002] With the acceleration of the domestic urbanization process, the power supply load in the city is increasing, and higher voltage transmission lines are required to enter the city. Power cables have the advantages of stable and reliable operation and beautify the city. They are gradually replaced in urban power transmission. With the trend of overhead lines, more and more high-voltage power cables are being laid in cities. Power cables with a voltage level of 110kV and above are generally designed with a single core. The main insulating material currently used in AC cables is generally cross-linked polyethylene (XLPE) , In the insulation structure of this kind of cable, there are often air gaps and harmful impurit...

AI Technical Summary

Problems solved by technology

[0002] With the acceleration of the domestic urbanization process, the power supply load in the city is increasing, and higher voltage transmission lines are required to enter the city. Power cables have the advantages of stable and reliable operation and beautify the city. They are gradually replaced in urban power transmission. With the trend of overhead lines, more and more high-voltage power cables are being laid in cities. Power cables with a voltage level of 110kV and above are generally designed with a single core. The main insulating material currently used in AC cables is generally cross-linked polyethylene (XLPE) , In the insulation structure of this kind of cable, there are often air gaps and harmful impurities due to the difficulty of processing technology or impure raw materials, or due to process reasons, there are gaps or semi-conductive conductors between the insulation and the semi-conductive shielding layer. The insulation layer is protruding, and partial discharge (PD) is easily generated at these air gaps and impurity tips. At the same time, various insulation defects may also occur during the installation and operation of power cables to cause partial discharge.

Due to the poor discharge resistance of extruded insulating materials such as XLPE, under the long-term action of partial discharge, the insulating materials will continue to age and eventually lead to insulation breakdown, resulting in serious accidents

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