System and method for accelerated water tree aging of 10kv XLPE cables

Abstract

The invention provides a system for accelerated water-treeing of a 10 kV crosslinked polyethylene cable sample. The system comprises an epoxy resin box body, a DC high-voltage source, mechanical arms, a grounding copper sheet and a heating plate, wherein a sealing hole allowing a cable to pass is formed in each of two opposite side edges of the epoxy resin box body; the two ends of the cable are exposed from the sealing holes which are sealed by two sealing rings; an insulating layer and a semi-conducting layer of one of the ends exposed out of the corresponding sealing holes are peeled off to expose a copper core; the DC high-voltage source is used for being connected with the copper core; a salt solution is injected into the epoxy resin box body to immerse the cable; one end of the grounding copper sheet is immersed into the salt solution, and the other end of the grounding copper sheet is grounded; the part, immersed into the salt solution, of the cable is needle-pierced to form a plurality of small holes; the heating plate is connected with the epoxy resin box body; the two mechanical arms are respectively arranged on the outer sides of the two sealing holes. The system can simulate the water-treeing, thermal and mechanical aging of crosslinked polyethylene cables in humid and over-heated environments, and meanwhile, well keeps the integrity of the cables.

Description

technical field [0001] The invention relates to the technical field of high-voltage cable detection, in particular to a system and method for accelerating water tree aging of 10kV cross-linked polyethylene cables. Background technique [0002] Water tree is a phenomenon of degradation of cross-linked polyethylene (XLPE) insulation. It is a dendrite formed by water immersion in the XLPE insulation layer and the interaction with the electric field. Water branches have hydrophilic characteristics. At the beginning, water branches are some chain-like water-filled holes, and then gradually form dendritic fine channels with hydrophilic surfaces. Under the action of moisture and electrical stress, water branches can grow within a few years. to about 1mm. In the cable, the areas where water trees appear are mainly the protrusions on the contact surface between the semiconductive layer and the insulating layer and the internal defects (pores, impurities, etc.) of the insulating laye...

AI Technical Summary

Problems solved by technology

[0003] During the long-term operation of the cable, due to the influence of the carrying capacity, laying method, and ambient temperature, local overheating will occur, resulting in aggravated thermal aging.

[0004] At the same time, the cable is subjected to mechanical forces such as improper traction and bending during installation, maintenance, and operation, which will cause mechanical aging of the cable under stress

[0005] These three types of aging are currently the most common types of aging, which have a greater impact on the safe use of cables

In the existing experimental equipment, there is still a lack of equipment for performing experiments on the three types of aging at the same time, so the present invention has great significance for simulating the water tree, heat, and mechanical aging caused by the operation and maintenance of cross-linked polyethylene cables in humid and overheated environments. strong application value

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