Method in the manufacturing of an insulated electric high voltage DC termination or joint

Patent metadata

Field	Value
Publication number	US-10855063-B2
Application number	US-201815870249-A
Country	US
Kind code	B2
Filing date	Jan 12, 2018
Priority date	Jan 31, 2013
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A method in the manufacturing of an insulated electric high voltage DC termination or joint includes providing an insulated electric high voltage DC cable including a high voltage DC conductor, a polymer based insulation system surrounding the high voltage DC conductor, the polymer based insulation system including an insulation layer and a semiconducting layer surrounding the insulation layer, and a grounding layer surrounding the semiconducting layer; removing the grounding layer and the semiconducting layer in at least one end portion of the high voltage DC cable, mounting a field grading adapter or joint body in the at least one end portion of the high voltage DC cable; and subjecting the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable for a heat treatment procedure, while being covered by the mounted field grading adapter or joint body.

First claim

The invention claimed is:

1. A method in the manufacturing of an insulated electric high voltage DC termination or joint comprising the steps of:
providing an insulated electric high voltage DC cable comprising a high voltage DC conductor, a polymer based insulation system surrounding the high voltage DC conductor, the polymer based insulation system comprising an insulation layer and a semiconducting layer surrounding the insulation layer, and a grounding layer surrounding the semiconducting layer;
removing the grounding layer and the semiconducting layer in at least one end portion of the high voltage DC cable, thereby exposing the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable;
mounting a field grading adapter or joint body in the at least one end portion of the high voltage DC cable, thereby covering the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable, the field grading adapter or joint body being part of the high voltage DC termination or joint, wherein at least one substance is present in the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable in a non-homogenous distribution; and
subjecting the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable for a heat treatment procedure, while being covered by the mounted field grading adapter or joint body, thereby equalizing a concentration of the at least one substance in the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable.

2. The method of claim 1 , further comprising the steps of:
temporarily covering the field grading adapter or joint body by a cover impermeable to the at least one substance present in the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable in a non-homogenous distribution before performing the step of subjecting; and
removing the cover after the step of subjecting.

3. The method of claim 2 , wherein a second insulated electric high voltage DC cable is provided, the second insulated electric high voltage DC cable comprising a second high voltage DC conductor; a polymer based insulation system surrounding the second high voltage DC conductor, the polymer based insulation system comprising an insulation layer and a semiconducting layer surrounding the insulation layer; and a grounding layer surrounding the semiconducting layer; the grounding layer and the semiconducting layer of the second insulated electric high voltage DC cable are removed in at least one end portion of the second insulated electric high voltage DC cable, thereby exposing the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable; and a field grading adapter or joint body of the second insulated electric high voltage DC cable is mounted in the at least one end portion of the second insulated electric high voltage DC cable, thereby covering the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable, wherein the at least one substance is present in the insulation layer of the polymer based insulation system in the at least one end portion of the second insulated electric high voltage DC cable in a non-homogenous distribution, and wherein the step of subjecting further comprises the step of:
subjecting the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable for the heat treatment procedure, while being covered by the mounted joint body of the second insulated electric high voltage DC cable, thereby equalizing the concentration of the at least one substance in the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable.

4. The method of claim 1 , wherein a second insulated electric high voltage DC cable is provided, the second insulated electric high voltage DC cable comprising a second high voltage DC conductor; a polymer based insulation system surrounding the second high voltage DC conductor, the polymer based insulation system comprising an insulation layer and a semiconducting layer surrounding the insulation layer; and a grounding layer surrounding the semiconducting layer; the grounding layer and the semiconducting layer of the second insulated electric high voltage DC cable are removed in at least one end portion of the second insulated electric high voltage DC cable, thereby exposing the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable; and a field grading adapter or joint body of the second insulated electric high voltage DC cable is mounted in the at least one end portion of the second insulated electric high voltage DC cable, thereby covering the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable, wherein the at least one substance is present in the insulation layer of the polymer based insulation system in the at least one end portion of the second insulated electric high voltage DC cable in a non-homogenous distribution, and wherein the step of subjecting further comprises the step of:
subjecting the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable for the heat treatment procedure, while being covered by the mounted joint body of the second insulated electric high voltage DC cable, thereby equalizing the concentration of the at least one substance in the insulation layer of the polymer based insulation system of the second insulated electric high voltage DC cable in the at least one end portion of the second insulated electric high voltage DC cable.

5. The method of claim 1 , wherein the field grading adapter or joint body comprises rubber as a field grading material.

Assignees

• Nkt Hv Cables Ab

Inventors

• Olsson Carl-Olof
• Saltzer Markus
• Lindgren Anders

Classifications

• H01B13/0165

  of the layers outside the outer conductor · CPC title

• H01B13/0162

  of the central conductor · CPC title

• H02G15/18

  protected by sleeves, e.g. for communication cable (two-part covers H02G15/10 {; preforms having internal stresses B29C61/00}) · CPC title

• H02G15/068

  connected to the cable shield only (H02G15/072 takes precedence) · CPC title

• H02G1/16

  for repairing insulation or armouring of cables · CPC title