Pål Keim Olsen

Associate Professor
+47 73412059 +47 99472950

Background and activities

Title of PhD project: 

Partial discharges in insulation materials exposed to combined DC and AC voltage

Supervisor:      Ass. Prof. Frank Mauseth              
Research Group:   Electric Power Systems          
Co-Supervisor:       Prof. Erling Ildstad
Project:   High Voltage AC and DC Subsea Cables for Offshore Wind Farms and Transmission Grids                    


HVAC subsea transmission is limited in terms of distance to shore: at about 50-70 km distance from shore the capacitive load of the subsea cables is too high, taking too much of the current carrying capability of the cables. It has been found that the HVDC system is economical for distances above 70 km from shore, and there is no practical limit in the distance from shore as for HVAC systems. The majority of cables already installed in AC and DC systems are mass impregnated cables, but there is a drive to use dielectric extruded cables for subsea applications.

The PhD work focus on the electric degradation phenomena which can occur in electric equipment in an offshore HVDC network, during steady state operation and under faults. In particular, the effect of DC voltage with superimposed AC voltage on partial discharges in the insulation. Simulation of partial discharges in cavities under DC superimposed AC voltage and ageing under such conditions is studied through lab experiments. The main materials to be studied are PEEK, but the model should be relevant for other materials like XLPE for cables and epoxy for converter transformers, generators and switchgear. The results from the work can be used when developing qualification tests and design of long cables and other electric equipment used in offshore HVDC networks.



Scientific, academic and artistic work

A selection of recent journal publications, artistic productions, books, including book and report excerpts. See all publications in the database

Journal publications

Part of book/report