Insulation aging diagnostic system and method based on 10kV XLPE cable

Abstract

The invention relates to an insulation aging diagnostic system and method based on a 10kV XLPE cable. The system comprises a water tree 10kV XLPE cable, a direct-current power supply, a high-voltage pulse power supply and a data collecting and processing unit. The method includes the steps that firstly, a negative direct-current voltage Vdc is exerted on the water tree 10kV XLPE cable; secondly, the high-voltage side of the cable is grounded, and trapped charges become residual charges in the grounding discharging process; thirdly, a high-voltage pulse voltage is exerted on the water tree 10kV XLPE cable, and voltage direct-current component signals on a resistor R are collected through the data collecting and processing unit, the time integral operation is performed, and the residual charge quality is obtained; fourthly, the water tree aging degree of the cable is judged according to the residual charge quantity. The insulation aging diagnostic system and method can well detect the water tree aging degree and is obvious in detection effect and capable of effectively preventing insulating accidents.

Description

technical field [0001] The invention belongs to the technical field of cross-linked polyethylene cable insulation aging analysis and diagnosis, in particular to an insulation aging diagnosis system and method based on 10kV XLPE cables. Background technique [0002] The degree of cableization of urban power grid is an important symbol to measure the technical level of urban power grid, and it is also a necessary means to promote the rapid progress of urban civilization and improve the urban living environment. In the past 30 years, various technologies of power cables at home and abroad have developed rapidly, especially the development of three-layer co-extrusion production process to manufacture XLPE cables, which makes XLPE cables need no oil supply equipment and have better fire resistance compared with oil-filled cables. , Simple installation and maintenance, good mechanical and electrical performance, etc., are adopted by more and more countries. At present, the cables...

AI Technical Summary

Problems solved by technology

Among these methods, each method has its own advantages and disadvantages, and none of them can reflect the water tree aging state of cable insulation well.

In recent years, the off-line diagnosis method that uses water trees as the object of aging diagnosis has AC excitation residual charge method, but its main disadvantage is that the release speed of residual charge is slow and the characteristic quantity is not obvious.

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