Blar i SINTEF Open på forfatter "Hestad, Øystein Leif Gurandsrud"

Viser treff 1-9 av 9

    • Cerman: Software for simulating streamer propagation in dielectric liquids based on the Townsend–Meek criterion 

      Madshaven, Inge; Hestad, Øystein Leif Gurandsrud; Åstrand, Per-Olof (Peer reviewed; Journal article, 2021)
      We present a software to simulate the propagation of positive streamers in dielectric liquids. Such liquids are commonly used for electric insulation of high-power equipment. We simulate electrical breakdown in a needle–plane ...

    • Conduction and Electric Fields in Dielectric Liquids in Needle-to-Plane Gaps 

      Hestad, Øystein Leif Gurandsrud; Aakre, Torstein Grav; Lundgaard, Lars Esben (Peer reviewed; Journal article, 2024)
      This paper describes measurements of conduction currents in both neat and commercial insulating liquids. Conduction in thermodynamic equilibrium has been measured by applying a low ac voltage in a uniform field. High-field ...

    • Field dependent conductivity of n-pentane 

      Hestad, Øystein Leif Gurandsrud; Linhjell, Dag; Lundgaard, Lars Esben; Samseth, Jarl Ø.; Unge, Mikael (Proceedings of IEEE International Conference on Dielectric Liquids;2017, Chapter; Peer reviewed, 2017)
      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 ...

    • Formation of micro-cracks at the surface of a high voltage cable screen induced by aluminum corrosion 

      Lesaint, Cedric Michel; Liland, Knut Brede; Mermigkas, Athanasios; Klusmeier, Katharina Kuhlefelt; Kantar, Emre; Hvidsten, Sverre; Hestad, Øystein Leif Gurandsrud (Chapter; Peer reviewed, 2023)
      The main purpose of this study is to investigate the adhesion between corroded aluminium conductor strands and the semi-conductive cable screen. In this paper it is proposed that increased adhesion is one of the pre-requisites ...

    • Modeling the transition to fast mode streamers in dielectric liquids 

      Madshaven, Inge; Åstrand, Per-Olof; Hestad, Øystein Leif Gurandsrud; Unge, Mikael; Hjortstam, O. (Proceedings of IEEE International Conference on Dielectric Liquids;2017, Chapter; Peer reviewed, 2017)
      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 ...

    • Modelling of Internal Pressure Dynamics in Mass-Impregnated Non-Draining HVDC Cables 

      Hestad, Øystein Leif Gurandsrud; Runde, Magne; Enoksen, Henrik; Magnusson, Niklas (Peer reviewed; Journal article, 2022)
      Changing the current loading of mass-impregnated non-draining power cables causes the pressure in the insulation to vary over a wide range. It is generally recognized that under certain conditions—typically after a large ...

    • 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 ...

    • Review of Water Treeing in Polymeric Insulated Cables 

      Abideen, Amar; Mauseth, Frank; Hestad, Øystein Leif Gurandsrud; Faremo, Hallvard (Peer reviewed; Journal article, 2022)
      Since discovering the water treeing phenomenon (WT) in polymeric cables in the early 1970s, water treeing has been presumed to be the main cable degradation mechanism for polymeric cables and has been extensively researched ...