Browsing SINTEF Open by Author "Hjortstam, Olof"
Now showing items 1-5 of 5
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Photoionization model for streamer propagation mode change in simulation model for streamers in dielectric liquids
Madshaven, Inge; Hestad, Øystein Leif Gurandsrud; Unge, Mikael; Hjortstam, Olof; Åstrand, Per-Olof (Journal article; Peer reviewed, 2019)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 ... -
Pre-breakdown phenomena in hydrocarbon liquids in a point-plane gap under step voltage. Part 2: behaviour under negative polarity and comparison with positive polarity
Lundgaard, Lars Esben; Linhjell, Dag; Hestad, Øystein Leif Gurandsrud; Unge, Michael; Hjortstam, Olof (Journal article; Peer reviewed, 2020)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 ... -
Prebreakdown phenomena in hydrocarbon liquids in a point-plane gap under step voltage. Part 1: behaviour at positive polarity
Linhjell, Dag; Lundgaard, Lars Esben; Unge, Michael; Hjortstam, Olof (Journal article; Peer reviewed, 2020)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 ... -
Pressure-Dependent Propagation of Streamers under Step Voltage in a long Point-Plane Gap in Transformer Oil
Linhjell, Dag; Lundgaard, Lars Esben; Unge, M.; Hjortstam, Olof (Peer reviewed; Journal article, 2020)The effect of pressure on positive and negative streamer propagation in a mineral transformer oil is studied in an 80 mm point-plane gap under step voltage. Increased pressure causes reduced stopping length for non-breakdown ... -
Simulation model for the propagation of second mode streamers in dielectric liquids using the Townsend-Meek criterion
Madshaven, Inge; Åstrand, Per-Olof; Hestad, Øystein; Ingebrigtsen, Stian; Unge, Mikael; Hjortstam, Olof (Journal article; Peer reviewed, 2018)