Til hovedinnhold

Øystein Hestad

Forsker

Øystein Hestad

Forsker

Øystein Hestad
Telefon: 971 12 257
Avdeling: Elkraftteknologi
Kontorsted: Trondheim

Publikasjoner og ansvarsområder

Publikasjoner

Publikasjon

Modeling the transition to fast mode streamers in dielectric liquids

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1526030

A simplified model for photoionization, modeling fast streamer propagation, is combined with an existing model for slow streamers, based on electron avalanches. Transitions from fast mode to slow mode, and from slow mode to fast mode, are investigated....

Forfattere Madshaven Inge Åstrand Per-Olof Hestad Øystein Leif Gurandsrud Hjortstam O.
År 2017
Type Del av bok/rapport
Publikasjon

Field dependent conductivity of n-pentane

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1526028

A sensitive differential charge measurement technique was used to measure the conduction current from a sharp needle in a needle plane geometry in n-pentane. The current was measured at voltages up to the threshold for streamer inception in n-pentane with a positive needle polarity. The measured cur...

Forfattere Hestad Øystein Leif Gurandsrud Linhjell Dag Lundgaard Lars Esben Samseth Jarl Ø. Unge Mikael
År 2017
Type Del av bok/rapport
Publikasjon

Photoionization Model for the Transition to Fast Mode Streamers in Dielectric Liquids

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1399267

The transition to fast mode streamers is explained through a model that includes a photoionization mechanism. The model assumes that photons are created in the head of the streamer, and that the photoionization cross section is dependent on the electric field through field dependent ionization poten...

Forfattere Madshaven Inge Smalø Hans Sverre Unge Michael Hestad Øystein Leif Gurandsrud
År 2016
Type Del av bok/rapport
Publikasjon

Thermal Decomposition of Cyclohexane by Kinetic Monte Carlo Simulations and its Relevance to Streamer Formation

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1399249

Kinetic Monte Carlo was used to simulate the decomposition of cyclohexane at temperatures up to 10 000 K. Rate constants needed for the simulations were obtained from literature and combined with differences in Gibbs free energy between the reactants and products. The degree of decomposition and an ...

Forfattere Hestad Øystein Leif Gurandsrud Vuong Au-Dung Madshaven Inge Åstrand Per-Olof Harald
År 2016
Type Del av bok/rapport
Publikasjon

Conductivity and permittivity of Midel 7131 : effect of temperature, moisture content, hydrostatic pressure and electric field

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1394037

Knowledge of the conductivity and permittivity of materials used in subsea connectors is needed to predict the electric field distribution in the connectors. The synthetic ester Midel 7131, being one of several dielectric liquids used in subsea connectors, has been chosen as a relevant candidate mat...

Forfattere Aakre Torstein Grav Ve Torbjørn Hestad Øystein
År 2016
Type Tidsskriftspublikasjon
Publikasjon

The effect of temperature cycling on mechanical and electrical properties of syndiotactic polypropylene

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1375207

Polypropylenes (PP) are a candidate to replace cross-linked polyethylene (XLPE) in medium voltage cables. This is due to its recyclability and potentially lower energy consumption during production. To prove to be an alternative, the PPs must meet the same requirements as for XLPE. The maximum servi...

Forfattere Aakre Torstein Grav Hestad Øystein Hølto Jorunn Hvidsten Sverre
År 2016
Type Del av bok/rapport
Publikasjon

Self-healing composites for high voltage electrical insulation

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1258142

A self-healing electrical insulation material for high voltage apparatuses has yet not been developed. Such a material would have been very attractive for electrical components installed in conditions were service failures cause time consuming and very expensive replacements. This paper reports resu...

År 2016
Type Del av bok/rapport
Publikasjon

Effect of static mechanical strain on the DC conductivity of extruded cross-linked polyethylene cable insulation

https://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1258129

DC current measurements were performed on a medium voltage XLPE cable at voltages from 8.5 to 65 kV (average field from 2.5 to 19 kV/mm). To assess the effect of mechanical strain on the conductivity of the insulation, the cable was wrapped around a tube with an outer diameter of 110 mm (max strain ...

Forfattere Hestad Øystein Leif Enoksen Henrik Hvidsten Sverre
År 2016
Type Del av bok/rapport
Vis alle publikasjoner hos Cristin