Accessory for high voltage direct current energy cables

Patent metadata

Field	Value
Publication number	US-9991690-B2
Application number	US-201515544607-A
Country	US
Kind code	B2
Filing date	Jan 21, 2015
Priority date	Jan 21, 2015
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

The present invention relates to an accessory for high-voltage direct-current (HVDC) energy cables comprising: at least one element made from a crosslinked elastomeric polymer material, and at least one scavenging layer comprising zeolite particles. The zeolite particles are able to scavenge, very efficiently and irreversibly, the by-products deriving from the cross-linking reaction, so as to avoid space charge accumulation in the element during the accessory lifespan. Moreover, the zeolite particles can prevent the crosslinking by-products present in the element of a non-degassed accessory from migrating towards the insulating layer of the energy cable on which the accessory is mounted.

First claim

The invention claimed is:

1. Accessory for high voltage direct current (HVDC) energy cables comprising: at least one element made from a crosslinked elastomeric polymer material, and at least one scavenging layer comprising zeolite particles, wherein the zeolite particles have a SiO 2 /Al 2 O 3 molar ratio equal to or lower than 15, and wherein the zeolite particles have a sodium content, expressed as Na 2 O, equal to or lower than 0.3% by weight.

2. The accessory according to claim 1 , wherein said scavenging layer is applied in a radial external position with respect to the element made from a crosslinked elastomeric polymer material.

3. The accessory according to claim 2 , wherein the element made from a crosslinked elastomeric polymer material is a least one of an insulating element and a stress-relief cone.

4. The accessory according to claim 3 , wherein said scavenging layer is applied in direct contact with the insulating element.

5. The accessory according to claim 3 , wherein an outer semiconducting layer is interposed between the insulating element and the scavenging layer.

6. The accessory according to claim 1 , wherein said scavenging layer is in a form selected from a polymeric sheath or a tape.

7. The accessory according to claim 6 , wherein said tape is a self-amalgamating tape or a hygroscopic tape.

8. The accessory according to claim 1 , wherein the zeolite particles have a maximum diameter of a sphere than can diffuse along at least one of the cell axes directions equal to or greater than 3 Å.

9. The accessory according to claim 1 , wherein said scavenging layer comprises a polymer material selected from elastomeric copolymers of the ethylene with at least one alpha-olefin, silicon polymers, polymers or copolymers of butane, butyl rubbers and mixture thereof.

10. The accessory according to claim 1 , wherein said scavenging layer comprises a polymer material having a 200% elastic modulus of from 2 MPa and 8 MPa according to ASTM D638-10.

11. The accessory according to claim 1 , said accessory being an electrical cable joint.

12. The accessory according to claim 1 , said accessory being an electrical cable termination.

Assignees

• Prysmian Spa

Inventors

• Boffi Paolo
• Marelli Marco

Classifications

• H01B9/02

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

• H01B3/441

  from alkenes · CPC title

• H02G15/08

  Cable junctions (for gas or oil filled cables H02G15/24) · CPC title

• H02G15/003 Primary

  Filling materials, e.g. solid or fluid insulation · CPC title

• H01B3/002

  Inhomogeneous material in general · CPC title