Highly-insulated high-voltage cable terminal

Abstract

The invention provides a highly-insulated high-voltage cable terminal. The highly-insulated high-voltage cable terminal comprises a stress cone and an insulating main body; the stress cone is preparedfrom the materials in parts by weight: 70-120 parts of liquid silicone rubber, 30-50 parts of a modifier, 3-6 parts of a maleamic acid and 2-4 parts of a vulcanizer; the insulating main body is prepared from the materials in parts by weight: 30-50 parts of EPDM, 0.8-1.2 parts of maleic anhydride, 15-25 parts of an ethane-butene copolymer, 20-40 parts of chlorinated polyethylene, 8-15 parts of hydrogenated butadiene-acrylonitrile rubber, 10-25 parts of nano SiO2, 2-5 parts of nano carbon black, 0.45-0.75 part of an initiator, 8-15 parts of a plasticizer, 2-4 parts of a silane coupling agent, 100-200 parts of a filler, 4-8 parts of a lubricating assistant, 6-10 parts of an active assistant, 2-3.5 parts of an anti-aging agent and 4-10 parts of a sulfurizing agent; acidified graphite is addedinto the liquid silicone rubber, graphite is pretreated by activation, the specific surface area and the surface hydroxyl number of the graphite are improved, the dispersity of the graphite in the liquid silicone rubber is improved, the generation of space charge is restrained, and the electrical performance of insulation structure is improved.

Description

technical field [0001] The invention relates to a highly insulating high-voltage cable terminal. Background technique [0002] The cable terminal is an important part of the cable line. It is installed at the end of the cable to ensure the gas connection between the cable line and other parts of the power system and to maintain insulation to the connection point. At present, the flexible DC transmission lines at home and abroad generally use cross-linked polymer As the insulating sheath of the cable terminal, ethylene (XLPE) has excellent chemical stability and solvent resistance. However, when the cross-linked polyethylene is in a high-voltage DC environment, a large amount of XLPE will accumulate inside the insulating layer due to material defects and other reasons. charge, and then distort the local electric field of the insulating layer, resulting in damage to the insulating layer; and due to the inherent characteristics of chemical crosslinking in XLPE, there is a probl...

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Problems solved by technology

[0002] The cable terminal is an important part of the cable line. It is installed at the end of the cable to ensure the gas connection between the cable line and other parts of the power system and to maintain insulation to the connection point. At present, the flexible DC transmission lines at home and abroad generally use cross-linked polymer As the insulating sheath of the cable terminal, ethylene (XLPE) has excellent chemical stability and solvent resistance. However, when the cross-linked polyethylene is in a high-voltage DC environment, a large amount of XLPE will accumulate inside the insulating layer due to material defects and other reasons. charge, and then distort the local electric field of the insulating layer, resulting in damage to the insulating layer; and due to the inherent characteristics of chemical crosslinking in XLPE, there is a problem of water tree aging at the end of the XLPE cable during operation, so that under the long-term action of the power plant, It may cause insulation breakdown and directly threaten the normal operation of the line; at present, the stress cone is generally made of silicone rubber, but the strength of silicone rubber is often not enough in the application process of the stress cone, and the stress cone is a key component for equalizing the electric field of the cable accessories , under the uneven electric field, the end of the stress cone is prone to the problem of field strength concentration, which leads to accelerated aging of the stress cone structure, and even corona and partial discharge, which seriously affect the long-term stable operation of the equipment;

[0003] In recent years, EPDM has been gradually applied in the field of cable terminals. EPDM has low density and excellent aging resistance. The rubber has good ozone resistance, heat resistance and low temperature flexibility, and can be used for Ozone resistance, weather resistance, and ultraviolet resistance, but based on its own structural characteristics, its tear strength, flame retardancy, oil resistance, and adhesion are poor, and the performance of pure EPDM insulated cables is difficult to meet the requirements of relevant specifications; and the DC electric field The generation of space charge in the medium is also a key factor in the aging of cable terminal insulation materials

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