JPS5820083B2 - How to use the power cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a conductor for a cryogenic cable.

As is well known, electric cables have a problem in that the skin effect increases as the size of the cable increases and the current increases, and the skin effect problem is particularly serious in cryogenic cables used at extremely low temperatures.

Multi-segmented conductors, in which the conductor is divided into several segments, are generally used as a measure against the skin effect, but this alone is far from sufficient.

Furthermore, twisting the arrangement of the conductor wires in each segment has been considered, but in reality, the conductor wires in each segment are manufactured by concentrically twisting, so there is a limit to the number of divisions in multiple divisions. The reality is that there is no definitive countermeasure against the skin effect.

In view of this situation, the present invention provides a method for producing a conductor for cryogenic cables that can significantly increase the number of conductor segments, can also perform twisting within each segment, and can significantly reduce the skin effect. The purpose is to provide a method.

The configuration of the present invention will be specifically explained with reference to the drawings showing one embodiment.

First, as shown in FIG. 1, the conductor wire 2 is spirally wound around the outer periphery of the temporary pipe 1.

A plastic pipe is suitable as the temporary pipe 1, and aluminum wire or copper wire is used as the conductor wire 2.
It is not limited to this.

Next, as shown in FIG. 2, the temporary pipe 1 is made flat.

This can be achieved, for example, by removing the air from the temporary pipe 1 or compressing it by external force.

Thereafter, the temporary pipe 1 is removed or incinerated to obtain a band-shaped conductor strand assembly as shown in FIG.

This conductor strand assembly is compression-molded into a slightly fan-shaped shape depending on the final shape of the cable conductor.

This compression molded state is shown in FIG. A strip-shaped conductor wire assembly as shown in FIG. 3 or a fan-shaped conductor wire assembly as shown in FIG. 5 is herein referred to as a flat conductor wire assembly.

FIG. 4 shows a conductor for a cryogenic cable in which a large number of flat conductor wire aggregates 4 are twisted around an inner tube 3.

The inner tube 3 is, for example, a corrugated tube or a spiral tube, and the inside thereof acts as a refrigerant passage.

The manufacturing method of the present invention as described above provides the following remarkable effects.

(1) Since the flat conductor strand assembly can be made into one segment, a multi-segmented conductor with an extremely large number of divisions can be obtained.

(2) In the flat conductor strand assembly, the conductor strands are all twisted and suspended, and the current flowing through each strand becomes uniform, so the skin effect is significantly reduced.

In addition, in the present invention, since a temporary pipe is used and there is a step of removing it later, there is a drawback that the cost of the conductor is somewhat high.

Therefore, although it is practical for general power cables, it cannot be said that it is extremely advantageous from an industrial perspective.

However, it is extremely advantageous for use in cryogenic cables because it can obtain a large current, and has extremely high industrial value.

[Brief explanation of the drawing]

1 to 5 are cross-sectional explanatory views showing each process of an embodiment of the present invention. 1...Temporary pipe, 2...Conductor wire,
3... Inner tube, 4... Flat conductor strand assembly.

Claims (1)

[Claims] 1. Wound a plurality of conductor strands in a spiral shape around the circumference of a temporary pipe, then form it into a flat shape, remove the temporary pipe, and open the inside of the flat conductor strand assembly. A method for manufacturing a conductor for a cryogenic cable, characterized by twisting a plurality of conductors around an inner tube that serves as a refrigerant passage.