Method for connecting return conductors of power supply DC coaxial cables and connection portion between power supply dc coaxial cables

Abstract

A power supply DC coaxial cable has a main conductor at the center, a main insulating layer outside the main conductor, and a return conductor comprising a large number of return conductor wires coaxially twisted outside the main insulating layer. In a method for connecting the return conductors at the connection portion between the power supply DC coaxial cables, a plurality of return conductor wires of the DC coaxial cables on both sides are adjacently arranged to form each return conductor wire bundle, and the ends of the return conductor wire bundles on both sides are faced to each other and then welded together. This enables the time required for welding the return conductor wires to be reduced and provides a method for connecting the return conductors of DC coaxial cables, which is also applicable to the return conductor connection between DC coaxial cables each having a different number of return conductor wires.

Description

technical field [0001] The present invention relates to a connection method of a return conductor on a connection portion between power coaxial cables having a return conductor coaxial with a central main conductor, and a connection portion of a DC coaxial cable for power. Background technique [0002] Figure 17 An example of a DC coaxial cable for electric power is shown. The center of the DC coaxial cable A has a main conductor 1, and its outer side is sequentially coaxially provided with an inner semiconducting layer 2, a main insulating layer 3, an outer semiconducting layer 4, a loop conductor 5, a loop inner semiconducting layer 6, and loop insulation Layer 7, circuit outer semiconductive layer 8, lead cladding 9 and anti-corrosion layer 10 (referring to patent document 1 figure 1 ). [0003] The main conductor 1 to the outer semiconducting layer 4 constitute a cable core 11 . The return conductor 5 is formed by concentrically stranding a plurality of return-condu...

AI Technical Summary

Problems solved by technology

[0008] For the return conductor connection of each DC coaxial cable with the same return conductor composition (wire diameter and wire number), although the existing return conductor can be used The method of butt welding the core wires one by one, but the conventional connection method has the following problems: if the number of core wires of the loop conductor is large, the number of welding times will increase, and the welding work time will become longer

[0010] In addition, in the case of soldering the return conductor core wire on the outer semiconductive layer of the cable core or the connection part, the following problems arise: the heat generated during soldering Thermal damage to the outer semiconductive layer and main insulation of the cable, and the outer semiconductive layer and reinforced main insulation of the connection

[0017] If the distance between the core wires of the loop conductor is widened, the following problems will occur: the electromagnetic shielding property is not sufficient

In addition, it can be considered that once a gap is formed between the loop conductor core wires, the flow of current through the adjacent loop conductor core wires almost disappears. Therefore, at the cable connection part, when the current flowing in each loop conductor core wire When the value is unbalanced, the current may be concentrated in some loop conductor core wires, resulting in abnormal heating

Images