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Effects of reduced pressure and additives on streamers in white oil in long point-plane gap

Effects of reduced pressure and additives on streamers in white oil in long point-plane gap

Kategori
Vitenskapelig artikkel
Sammendrag
Recent experiments show that modern dielectric liquids behave differently from traditional mineral oil, particularly with respect to breakdown voltages for lightning impulse. This paper describes an experimental investigation addressing underlying reasons for this. The influences of reduced pressure and additives on streamers in white oil were investigated under both positive and negative polarities using an 8 cm long point-plane gap. Reduced pressure significantly accelerates streamers, thus increasing stopping length and reducing both breakdown and acceleration voltages. With increasing applied voltage, different typical propagation modes of streamers were recorded for both polarities. A low ionization potential additive strongly affects positive streamers. It significantly changes streamer velocity and reduces the breakdown voltage but increases the acceleration voltage where breakdown streamer velocity increases drastically. Adding an electron scavenger influences streamers of both polarities, but it mainly increases the velocity of negative streamers and results in a reduction of both the breakdown and the acceleration voltages. The propagation mechanisms of streamers are also discussed. © 2013 IOP Publishing
Oppdragsgiver
  • Research Council of Norway (RCN) / 200631
Språk
Engelsk
Forfatter(e)
Institusjon(er)
  • Norges teknisk-naturvitenskapelige universitet
  • SINTEF Energi AS / Elkraftteknologi
  • Sverige
År
Publisert i
Journal of Physics D: Applied Physics
ISSN
0022-3727
Forlag
Institute of Physics Publishing (IOP)
Årgang
46
Hefte nr.
25