Cristin-resultat-ID: 1920434
Sist endret: 6. juli 2021, 11:01
NVI-rapporteringsår: 2021
Resultat
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
2021

A Setup for Measuring Bubbling from Paper in Transformer Oil under Simulated sudden Overload

Bidragsytere:
  • Dag Linhjell og
  • Lars Esben Lundgaard

Bok

2021 IEEE Electrical Insulation Conference - EIC
ISBN:
  • 978-1-6654-1564-4

Utgiver

IEEE
NVI-nivå 1

Om resultatet

Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Under utgivelse/in press
Publiseringsår: 2021
Sider: 572 - 575
ISBN:
  • 978-1-6654-1564-4

Klassifisering

Fagfelt (NPI)

Fagfelt: Elkraft og elektrotekniske fag
- Fagområde: Realfag og teknologi

Beskrivelse Beskrivelse

Tittel

A Setup for Measuring Bubbling from Paper in Transformer Oil under Simulated sudden Overload

Sammendrag

Paper insulation on transformer windings may contain moisture, from aging or moisture ingress through breathers. A sudden overload will cause the insulation to heat much faster than the oil, and the moisture forced out of the insulation may not dissolve in the much colder oil, with bubbling as a result. Several studies have addressed bubbling temperature depending on winding moisture, aging state or pre-overload temperature, but some results are conflicting between studies. A setup has therefore been built to study bubbling. One heating system circulates oil with "pre-overload" temperature of up to 120℃. Moisture level is controlled by circulating through a cellulose reservoir with cellulose of known moisture. Another system heats one paper covered electrode controlled from 20℃ to 200℃ in about 15 minutes. Shock heating with a temperature increase of 80℃ in 30 seconds is possible. Bubbling can be detected optically through viewports, or by resulting discharges if applying 20 – 30kV between the covered electrode and a high voltage electrode, with an adjustable gap of normally 2mm. The covered electrode is insulated from ground and has a connection for current or discharge measurements. The setup has been tested with low density pressboard with 6% moisture, resulting in a bubbling temperature of 163℃, which other studies with paper only have found for about 1% moisture. Presently, the setup does not have adjustable pressurization, but it is made for easy expansion with pressure control, both higher than and lower than normal atmosphere. Keywords— transformer, winding overload, bubbling

Bidragsytere

Dag Linhjell

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Lars Esben Lundgaard

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS
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Resultatet er en del av Resultatet er en del av

2021 IEEE Electrical Insulation Conference - EIC.

EIC2021, .. 2021, IEEE. Vitenskapelig antologi/Konferanseserie
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