Publikasjoner og ansvarsområder
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
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...
Photoionization model for streamer propagation mode change in simulation model for streamers in dielectric liquids
Conductivity and capacitance of streamers in avalanche model for streamer propagation in dielectric liquids
Chemical ageing of subsea mass impregnated insulation cable paper
Simulation model for the propagation of second mode streamers in dielectric liquids using the Townsend-Meek criterion
Modeling the transition to fast mode streamers in dielectric liquids
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....
Field dependent conductivity of n-pentane
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...
Conductivity and permittivity of Midel 7131 : effect of temperature, moisture content, hydrostatic pressure and electric field
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...
Photoionization Model for the Transition to Fast Mode Streamers in Dielectric Liquids
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...