Cristin-resultat-ID: 1812951
Sist endret: 15. september 2020 16:01
NVI-rapporteringsår: 2020
Resultat
Vitenskapelig artikkel
2020

Internal pressures and pressure gradients in mass-impregnated HVDC cables during current cycling

Bidragsytere:
  • Magne Runde
  • Erik Jonsson
  • Niklas Magnusson og
  • Kristian Thinn Solheim

Tidsskrift

IEEE transactions on dielectrics and electrical insulation
ISSN 1070-9878
e-ISSN 1558-4135
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2020
Publisert online: 2020
Trykket: 2020
Volum: 27
Hefte: 3
Sider: 915 - 923
Open Access

Importkilder

Scopus-ID: 2-s2.0-85085651728

Beskrivelse Beskrivelse

Tittel

Internal pressures and pressure gradients in mass-impregnated HVDC cables during current cycling

Sammendrag

The internal pressures in the insulation of two 5-m long pieces of a state-of-the art mass-impregnated non-draining subsea cable have been measured under load current cycling at ambient temperatures ranging from 3 to 37 °C. Thermal expansion of the mass gives in some cases rather extreme internal pressures (>30 bar) and radial pressure gradients (>1.5 bar/mm) in the insulation. This leads to an outwardly directed flow of mass during loading. After a load turn-off, the pressure drops rapidly. Values below 100 mbar were measured in the inner parts of the insulation. The backflow of mass proceeds much slower because the pressure gradient now is smaller. Such a radial redistribution of the mass and the low pressures are assumed to influence the dielectric properties of the insulation as the risk of creating harmful shrinkage cavities is believed to increase. For all the investigated ambient temperature levels the internal pressure in the insulation became around 1 bar or less when isothermal conditions were reached after the load turn-offs. This demonstrates that thermal expansion and contraction of the mass are not the sole mechanisms determining the internal pressures in such cables. Other, still unidentified phenomena are also contributing.

Bidragsytere

Magne Eystein Runde

Bidragsyterens navn vises på dette resultatet som Magne Runde
  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Erik Jonsson

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Niklas Magnusson

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Kristian Thinn Solheim

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS
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