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Øystein Hestad

Research Manager

Øystein Hestad

Research Manager

Øystein Hestad
Phone: 971 12 257
Department: Electric Power Technology
Office: Trondheim

Publications and responsibilities

Publication
https://www.sintef.no/en/publications/publication/?pubid=CRIStin+1807150

This study addresses the dielectric performance of nonpolar hydrocarbon liquids and mineral oils under negative polarity stress. 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 ...

Year 2020
Type Journal publication
Publication
https://www.sintef.no/en/publications/publication/?pubid=CRIStin+1763255

Radiation is important for the propagation of streamers in dielectric liquids. Photoionization is a possibility, but the effect is difficult to differentiate from other contributions. In this work, we model radiation from the streamer head, causing photoionization when absorbed in the liquid. We fin...

Authors Madshaven Inge Hestad Øystein Leif Gurandsrud Unge Mikael Hjortstam Olof Åstrand Per-Olof
Year 2020
Type Journal publication
Publication
https://www.sintef.no/en/publications/publication/?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....

Authors Madshaven Inge Åstrand Per-Olof Hestad Øystein Leif Gurandsrud Unge Mikael Hjortstam O.
Year 2017
Type Part of a book/report
Publication
https://www.sintef.no/en/publications/publication/?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...

Year 2017
Type Part of a book/report
Publication
https://www.sintef.no/en/publications/publication/?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...

Authors Madshaven Inge Smalø Hans Sverre Unge Michael Hestad Øystein Leif Gurandsrud
Year 2016
Type Part of a book/report
Publication
https://www.sintef.no/en/publications/publication/?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 ...

Authors Hestad Øystein Leif Gurandsrud Vuong Au-Dung Madshaven Inge Åstrand Per-Olof Harald
Year 2016
Type Part of a book/report
Publication
https://www.sintef.no/en/publications/publication/?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...

Year 2016
Type Journal publication