Cristin-resultat-ID: 1807148
Sist endret: 3. september 2020, 13:40
NVI-rapporteringsår: 2020
Resultat
Vitenskapelig artikkel
2020

Prebreakdown phenomena in hydrocarbon liquids in a point-plane gap under step voltage. Part 1: behaviour at positive polarity

Bidragsytere:
  • Dag Linhjell
  • Lars Esben Lundgaard
  • Michael Unge og
  • Olof Hjortstam

Tidsskrift

Journal of Physics Communications
ISSN 2399-6528
e-ISSN 2399-6528
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2020
Publisert online: 2020
Trykket: 2020
Volum: 4
Artikkelnummer: 045012
Open Access

Beskrivelse Beskrivelse

Tittel

Prebreakdown phenomena in hydrocarbon liquids in a point-plane gap under step voltage. Part 1: behaviour at positive polarity

Sammendrag

This study addresses the dielectric performance of nonpolar hydrocarbon liquids and mineral oils under positive polarity stress. It is of interest to improve knowledge on how functional properties of dielectric liquids vary, as new brands arrive in the market, and existing standards are unsuited for documenting the dielectric functional parameters of these new liquids. Stopping length for non-breakdown streamers, breakdown voltages and velocities for various pre-breakdown streamer modes have been studied for a selection of model liquids (cyclohexane and white oils), for a gas to liquid oil, and a refined naphthenic transformer oil. Studies of propagation modes were done using an 80 mm point to plane gap and a step voltage with a 0.5 μs rise time. Light emission and pre-breakdown currents have been recorded and instantaneous velocities have been derived from images of propagating streamers. There are clear differences in streamer stopping lengths and mode occurrence and mode velocities between these liquids. The differences seem to be influenced by molecular sizes governing evaporation energy for streamer formation and by concentration of aromatics which can be coupled to electron avalanche processes in the streamer heads.

Bidragsytere

Dag Linhjell

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Lars Esben Lundgaard

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Michael Unge

  • Tilknyttet:
    Forfatter
    ved ABB

Olof Hjortstam

  • Tilknyttet:
    Forfatter
    ved ABB Ltd.
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