26/35kV or 27.5kV silicon rubber cold contraction type through joint

Abstract

A 26/35kV or 27.5kV silicon rubber cold contraction type through joint comprises an insulation layer. An outer shielding layer is arranged on an outer surface of the insulation layer, a balance pipe is composited on a middle inner wall of the insulation layer, a stress cone is arranged on inner walls at two ends of the insulation layer respectively, two ends of the balance pipe are provided with a two-cone structure respectively, each two-cone structure comprises an inner cone expanding outwards and an outer cone, and the inner cone and the outer cone are connected transitionally through a section of circular pipe with the diameter larger than the inner diameter of the balance pipe. The structure of the balance pipe is modified to optimize electric field distribution, so that electric field concentration at the ends and tangential positions along an interface of the balance pipe is avoided, electric field intensity is effectively reduced, electric field is balanced, a semi-conducting layer in a cable is rationally and effectively restored, electrical performance of the through joint is improved, accident rate is lowered, and stable operation of an electrical system is guaranteed in the long term.

Description

technical field [0001] The invention relates to an electric field distribution that can be optimized, improves the electric field distribution at the end of the pressure equalizing tube and the electric field intensity along the tangential direction of the interface, and provides a silicone rubber cooler with excellent and stable electrical performance for the 26 / 35kV power system and the 27.5kV electrified railway system. Retractable straight connector. Background technique [0002] Silicone rubber cold-shrinkable straight-through joint (commonly known as cable intermediate joint) is a whole composed of stress cone, pressure equalizing tube, insulating layer and outer shielding layer; it is used for power system lines, connecting two cables to form a continuous circuit accessory . [0003] Existing silicone rubber cold-shrink straight joints such as Figure 4 As shown, it includes an insulating layer 300, an outer shielding layer 400 is arranged on the outer surface of the...

AI Technical Summary

Problems solved by technology

This kind of silicone rubber cold-shrinkable straight-through joint is suitable for the cable connection of 26 / 35kV power system, and the quality of the cable connection is often unstable, causing electric accidents, and it is not suitable for use as the intermediate joint of the 27.5kV electrified railway system cable.

The main reason is that the wall thickness of the pressure equalizing tube 200 of the 26 / 35kV or 27.5kV cable intermediate joint produced by various manufacturers is generally 4-6mm, and the end of the pressure equalizing tube 200 is a simple arc transition. Due to the limitation of the wall thickness of the pressure tube 200, the radius of the arc is less than 6mm, therefore, the silicone rubber cold-shrinkable straight-through joint cannot carry out the balanced distribution of the electric field and the evacuation of the electric stress; and the generation of corona cannot be solved, resulting in the existence of potential Poor, so that the insulating layer 300 is easily damaged; thus forming the problem that the outer shielding layer 400 is broken down by the equalizing tube 200 or the outer shielding layer 400 is broken down along the cable insulation surface; thus resulting in unstable product quality and increasing the accident rate , and cannot guarantee long-term operation, which will cause inconvenience and loss to the power supply department and the majority of users

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