Power cable

Patent metadata

Field	Value
Publication number	US-11309102-B2
Application number	US-201716326013-A
Country	US
Kind code	B2
Filing date	Mar 30, 2017
Priority date	Aug 18, 2016
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

Provided is a power cable, and more particularly, to an ultra-high-voltage underground or submarine cable. In detail, the present invention relates to a power cable which is capable of effectively preventing a decrease in dielectric strength due to penetration of copper powder from a copper conductor into an insulating layer, thereby increasing the lifespan thereof, is capable of preventing damage to insulating paper, semiconductor paper, etc. even when repeatedly bent and unfolded, thereby maintaining an interlayer structure formed by winding the insulating paper, the semiconductor paper, etc., and is capable of improving bendability, flexibility, installability, workability, etc.

First claim

The invention claimed is:

1. A power cable comprising:
a conductor;
an inner semi-conductive layer covering the conductor;
an insulating layer covering the inner semi-conductive layer;
an outer semi-conductive layer covering the insulating layer;
a metal sheath layer covering the outer semi-conductive layer;
and a cable protection layer covering the metal sheath layer, wherein the inner semi-conductive layer comprises a plurality of layers formed by horizontally winding semi-conductive paper,
wherein the plurality of layers comprise at least one layer formed by overlap-winding the semi-conductive paper such that portions of a width of the semi-conductive paper overlap each other, when the semi-conductive paper is horizontally wound,
wherein a total width of the inner semi-conductive layer is in a range of 0.2 to 1.5 mm.

2. The power cable of claim 1 , wherein remaining layers of the plurality of layers of the inner semi-conductive layer, other than the at least one layer formed by overlap-winding the semi-conductive paper, comprise layers formed by gap-winding semi-conductive paper such that regular gaps are formed between portions of the horizontally wound semi-conductive paper and the gaps in a certain layer are covered with sheets of semi-conductive paper forming layers above and below the certain layer.

3. The power cable of claim 1 , wherein the at least one layer formed by overlap-winding the semi-conductive paper comprises a layer directly above the conductor.

4. The power cable of claim 1 , wherein an overlap ratio of the at least one layer formed by overlap-winding the semi-conductive paper is in a range of 20 to 80%, the overlap ratio being a ratio between overlapping portions of the semi-conductive paper and a width of the semi-conductive paper.

5. The power cable of claim 1 , wherein a number of the plurality of layers of the semi-conductive paper is in a range of 4 to 10,
and
the semi-conductive paper has a width of 15 to 30 mm.

6. The power cable of claim 1 , wherein the semi-conductive paper comprises carbon paper obtained by processing insulating paper with carbon black.

7. The power cable of claim 1 , wherein the insulating layer comprises a plurality of layers formed by horizontally winding insulating paper,
wherein the plurality of layers comprise layers formed by gap-winding the insulating paper such that regular gaps are formed between portions of the horizontally wound insulating paper and the gaps in a certain layer are covered with sheets of insulating paper forming layers above and below the certain layer.

8. The power cable of claim 7 , wherein the insulating layer comprises an inner insulating layer, an intermediate insulating layer, and an outer insulating layer which are sequentially stacked,
wherein each of the inner insulating layer and the outer insulating layer is formed of kraft paper impregnated with insulating oil,
the intermediate insulating layer is formed by semi-synthetic paper impregnated with the insulating oil,
wherein the semi-synthetic paper comprises:
a plastic film; and
kraft paper stacked on at least one surface of the plastic film, and
the inner insulating layer and the outer insulating layer have resistivity lower than that of the intermediate insulating layer.

9. The power cable of claim 8 , wherein a thickness of the inner insulating layer is 1 to 10% of a total thickness of the insulating layer,
a thickness of the intermediate insulating layer is 75% or more of the total thickness of the insulating layer, and
a thickness of the outer insulating layer is 5 to 15% of the total thickness of the insulating layer.

10. The power cable of claim 9 , wherein the thickness of the outer insulating layer is greater than that of the inner insulating layer.

11. The power cable of claim 1 , wherein the cable protection layer comprises an inner sheath, bedding layers, a metal reinforcement layer, and an outer sheath.

12. The power cable of claim 11 , wherein the cable protection layer further comprises a wire sheath and an outer serving layer.

Assignees

• Ls Cable & System Ltd

Inventors

• Jang Sung Woo
• Gwag Jae Cheol

Classifications

• H01B9/027 Primary

  composed of semi-conducting layers · CPC title

• H01B7/2813

  Protection against damage caused by electrical, chemical or water tree deterioration · CPC title

• H01B7/14

  Submarine cables · CPC title

• H01B7/0216

  Two layers · CPC title

• H01B3/48 Primary

  fibrous materials (fibre-reinforced plastics H01B3/47) · CPC title