Crosslinked polyethylene power cable intermediate connector and manufacturing method thereof

Abstract

The invention provides a 500kV and below crosslinked polyethylene power cable intermediate connector and a manufacturing method thereof. The manufacturing method comprises the steps: stripping the twoends of a cable and enabling at least a cable conductor, a semi-conductive layer in the cable conductor and a cable main insulating layer to be exposed and fusing the cable conductors of the two ends; recovering the semi-conductive layer in the connector: mounting the semi-conductive pipe prefabricated from the polyethylene semi-conductive material to the connecting position of the cable conductors of the two ends and covering at least the cable conductor and the semi-conductive layer in the cable conductor and mounting a pressing mold on the semi-conductive pipe and heating the pressing mold; recovering the main insulating layer of the connector: and mounting a connector insulating forming mold and at least partially covering the cable main insulating layer and the semi-conductive layerin the connector by the mold and heating the mold after the polyethylene granular material fully fills in the mold. The invention also provides the intermediate connector manufactured by the method. The connector manufactured by the manufacturing method and the cable body form a consistent structure, and the electric property of the internal electric field stress distribution is equivalent to thatof the cable body.

Description

technical field [0001] The invention relates to a cable accessory in the field of power cable transmission system, more specifically, to a cross-linked polyethylene power cable intermediate connection joint and a manufacturing method. Background technique [0002] With the progress of urban power grid reconstruction projects, it has become a trend for power cables to replace overhead lines. Power cables have the advantages of good insulation performance, large transmission capacity, light structure, and no height drop restrictions, occupying an absolute advantage in the field of power transmission applications. status. [0003] There are also problems in the wide application of power cables. According to statistics, 70%-80% of the faults of power cables in operation occur at the cable joints, which are the main reasons for the failure of the cable joints to operate normally. ) function is that the structural materials of the cable joints are aging and fail, especially the i...

AI Technical Summary

Problems solved by technology

The reinforced insulating layer 2 is made of silicone rubber or EPDM rubber, which are two completely different insulating media from the cable insulating cross-linked polyethylene; the ratio of the conductivity of the two insulating media is uneven, and it is easy to generate distortion of the electric field; due to the two Moisture, impurities and harmful substances are easily brought into the natural movable interface 3 between the insulation materials of different materials, and are easily polarized by the electric field and thermal field, resulting in electric field distortion, resulting in joint failure

Furthermore, the conductors of the overall prefabricated joint are connected by cold crimping 6 and metal equalizing cover 5; due to the characteristics of the internal structure of the overall prefabricated joint, the electric field distribution of the cable body cannot be consistent, and the internal electric field distribution is relatively irregular, and long-term operation promotes the concentration of the electric field Partial discharge occurs in some places and leads to joint breakdown, which brings serious hidden dangers to the operation of the power grid

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