A method for manufacturing high-voltage cross-linked polyethylene insulated cable molded insulating joint

Abstract

The invention discloses a manufacturing method for a molding-type insulation connector of a high-voltage cross-linked polyethylene insulated cable. The manufacturing method comprises the steps of 1) stripping and pre-processing the cable; 2) welding a conductor; 3) performing shielding and molding on the conductor; 4) molding an I segment of an insulation main body of the connector by a template method; 5) molding an I segment of insulation shielding of the connector by the template method; 6) molding an II segment of the insulation main body of the connector by the template method; 7) moldingan II segment of insulation shielding of the connector by the template method; 8) performing vulcanization; 9) degassing; 10) wrapping a belt material; and 11) installing an insulation copper shell.According to the manufacturing method for the molding-type insulation connector of the high-voltage cross-linked polyethylene insulated cable, an original integrated pre-fabricated connector is abandoned, a molding recovery conductor shielding layer, an insulation layer and an insulation shielding layer with materials same as a cable body are employed, no physical interface exists, integration ofconnector main insulation and cable main insulation is achieved, so that the cable is free from influence of thermal expansion and cold shrinkage, good water prevention performance is achieved, and electric field and hot field are uniform and stable in distribution.

Description

technical field [0001] The invention belongs to a cable intermediate joint, in particular to a method for manufacturing a molded insulating joint of a high-voltage cross-linked polyethylene insulated cable. Background technique [0002] High-voltage cables of 66kV and above are mostly single-core cable systems. There is an induced voltage in the metal sheath and it increases with the increase of the cable length. The superposition will endanger personal safety, especially when short-circuit faults, lightning shocks or operating overvoltages occur in the line. In addition, if both ends of the cable shield are directly grounded, a large circulation loss will be generated, which will cause the cable to heat up, reduce the ampacity, and accelerate the thermal aging of the cable. Therefore, when the single-core high-voltage cable line is very long When using an insulated joint (the metal sheath of the cable at both ends of the joint and the insulation shield of the cable are elec...

AI Technical Summary

Problems solved by technology

[0003] Nowadays, the high-voltage cable accessories commonly used in China are integral prefabricated connectors, but the prefabricated accessories are assemblies of different materials, and the space charge is easy to accumulate at the interface of different materials, which makes the local field strength distorted, and even causes electrical treeing and breakdown , on the other hand, due to the influence of the operating temperature, the thermal expansion and contraction properties of different materials are different, which will lead to a movable interface at the material interface, which is susceptible to moisture intrusion and accelerates joint cracking. Under the action of electric field and thermal field, it will relax due to the decrease of elastic modulus, which will reduce the interface pressure and the precipitation of additives in rubber insulating parts, which will eventually lead to a decrease in insulation performance and potential safety hazards. In addition, the overall prefabricated joint must be fixed after the completion Operations such as moving and transferring cannot be carried out, otherwise the internal components will slip or be misplaced, posing safety hazards. From the perspective of project budget, the size of the overall prefabricated joint is too large, and it is necessary to set up a special widening in the cable trench or cable tunnel Sections are used to place joints, which greatly increases the infrastructure cost of cable lines

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