Welding method for large-section profile conductors of flexible joints of UHV DC submarine cables

Abstract

The invention discloses a welding method of a large-section molded line conductor of an ultrahigh-voltage direct-current submarine cable flexible joint. The welding method comprises the following steps of (1) respectively straightening a first cable and a second cable which need to be welded; (2) removing all structures except conductors from the ends of the first and second cables, and clamping the ends; cutting off single lines of the conductors of each layer of the first cable in different positions; and cutting off single lines of the conductors of each layer of the second cable in corresponding positions, and separating by utilizing a deconcentrator; (3) welding the single lines of the center conductors of the first cable and the second cable, and grinding; (4) recovering the single lines of molded lines of the first layers of the first cable and the second cable one by one, and welding; grinding the welding positions to the outside diameter of the first layer of a conductor body; and (5) recovering to weld the molded lines of the conductors of other layers layer by layer by adopting the method of the step (4). According to the welding method, after the large-section molded line conductor is welded, the conductor resistance and the welding strength of the molded lines can be guaranteed, the outside diameter and shape of the welding position of the conductor can be guaranteed, and the strength and bending properties of the conductor in the welding position meet the relevant requirements of submarine cables.

Description

technical field [0001] The invention relates to a welding method, in particular to a conductor welding and recovery method for a large cross-section stranded copper conductor used in a flexible joint of an ultra-high voltage submarine power cable. Background technique [0002] The DC cable has the advantages of high transmission efficiency, small line loss, convenient adjustment of current and change of power transmission direction, no influence of different grid frequencies, relatively low cost of long-length lines, etc., especially for long-length submarine power transmission, it may be the only one solution. [0003] Due to the limitation of production length and transportation conditions, the production length of DC submarine cables may not fully meet the requirements of line length, and the submarine cables must be connected in a suitable way to meet the requirements of line length. [0004] There are usually two ways to connect submarine cables. One is to use a speci...

AI Technical Summary

Problems solved by technology

However, the existing welding methods cannot simultaneously meet the technical indicators of electrical resistance, mechanical strength and bending performance for conductors with large cross-sections.

The cross section of the soft joint welding conductor is the nominal cross section of 3000mm 2 , is currently the conductor with the largest cross-section for cables, much larger than the maximum cross-section of 2500mm specified in the current standard GB / T 3956-2008 2 Conductors for cables, there is no research report on welding methods

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