Termination kit for DC cable

Patent metadata

Field	Value
Publication number	US-9966674-B2
Application number	US-201415120592-A
Country	US
Kind code	B2
Filing date	Jul 24, 2014
Priority date	Feb 21, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A termination connection box for a direct-current (DC) cable, including: a connecting semiconducting layer configured to cover an exposed conductor of the DC cable and an insulating layer of the DC cable; a conductor withdrawal rod electrically connected to the exposed conductor of the DC cable; and a heat shrinkable tube formed of functionally gradient material having non-linear electrical characteristics. The heat shrinkable tube includes: a first end electrically connected to the conductor and which covers a portion of the conductor withdrawal rod and the connecting semiconducting layer; a second end opposite to the first end, electrically connected to the outer semiconducting layer, and which covers a portion of the outer semiconducting layer; and a middle portion positioned between the first end and the second end, and which is in direct contact with and covers an outer circumferential surface of the insulating layer.

First claim

What is claimed is:

1. A termination connection box for a direct-current (DC) cable, in which when an outer semiconducting layer, a metal sheath provided at an outer side of the outer semiconducting layer and electrically connected to the outer semiconducting layer, an insulating layer, and an inner semiconducting layer are sequentially removed, a conductor is exposed, the termination connection box comprising:
a connecting semiconducting layer configured to wrap an exposed portion of the conductor and a portion of the insulating layer adjacent to the exposed portion of the conductor;
a conductor withdrawal rod electrically connected to the conductor; and
a heat shrinkable tube formed of functionally gradient material having non-linear electrical characteristics,
wherein the heat shrinkable tube includes:
a first end electrically connected to the conductor and which covers a portion of the conductor withdrawal rod and the connecting semiconducting layer which wraps the exposed portion of the conductor;
a second end opposite to the first end, electrically connected to the outer semiconducting layer, and which covers a portion of the outer semiconducting layer; and
a middle portion positioned between the first end and the second end, and which is in direct contact with and covers an outer circumferential surface of the insulating layer, and

wherein the heat shrinkable tube is configured to discharge space charges accumulated in the insulating layer via the outer semiconducting layer and the metal sheath when the space charges accumulated in the insulating layer exceeds a predetermined level.

2. The termination connection box of claim 1 , wherein at least a portion of the heat shrinkable tube is thicker than a remaining region thereof.

3. The termination connection box of claim 2 , wherein the heat shrinkable tube is thicker on the portion of the outer semiconducting layer, which is covered by the heat shrinkable tube, than on a remaining portion of the outer semiconducting layer.

4. The termination connection box of claim 2 , wherein the heat shrinkable tube comprises:
a first heat shrinkable tube configured such that one end and another end thereof on the conductor of the cable are respectively electrically connected to the conductor and the outer semiconducting layer; and
a second heat shrinkable tube formed on an outer side of the first heat shrinkable tube to a predetermined length.

5. The termination connection box of claim 1 , wherein the heat shrinkable tube has a volume resistance of 10 8 to 10 11 Ωm.

6. The termination connection box of claim 1 , wherein the heat shrinkable tube has a relative permittivity of 15 or more.

7. The termination connection box of claim 1 , wherein the heat shrinkable tube comprises a mixture of a polymer and at least one among ZnO, carbon black, and SiC.

8. A direct-current (DC) cable comprising the termination connection box of claim 1 .

9. The DC cable of claim 8 , wherein the DC cable comprises an insulating layer formed of a cross-linked polyethylene composition including 0.2 to 5 parts by weight of magnesium oxide with respect to 100 parts by weight of polyethylene resin.

10. The DC cable of claim 8 , wherein the conductor, the inner semiconducting layer, the insulating layer, and the outer semiconducting layer are sequentially formed,
wherein at least a portion of the insulating layer is formed of compound insulating paper in which kraft paper is stacked on top and bottom surfaces of polypropylene resin.

11. The DC cable of claim 10 , wherein the insulating layer comprises insulating paper in which a surface thereof which is in contact with the inner semiconducting layer and a surface thereof which is in contact with the outer semiconducting layer are formed of only kraft paper.

Assignees

• Ls Cable & System Ltd
• Ls Cable & System Ltd

Inventors

• Chae Byung Ha

Classifications

• H02G15/046

  with bores or protruding portions allowing passage of cable conductors · CPC title

• H01R4/68

  Connections to or between superconductive connectors · CPC title

• H01B9/02

  with screens or conductive layers, e.g. for avoiding large potential gradients · CPC title

• H02G15/043

  with end caps, e.g. sleeve closed at one end · CPC title

• H01R4/723 Primary

  Making a soldered electrical connection simultaneously with the heat shrinking · CPC title