PhD project (Industrial Research)
by Jesper Hjerrild
Defence:
June 17, 2002
Project period:
April 1, 1999 to April 1, 2002
Background and description:
This Industrial Ph.D. project is based on the increasing use of HVDC connections between electric power systems and long distance electric power transmission. At the moment there is a large potential for electric power transmission in Europe which requires HVDC connections.
Based on this it is necessary to develop new types of HVDC cables which optimize the technical, economical and environmental properties for the HVDC cable. This means that polymer-based insulation for HVDC cables are of great interest as it provides significant advantages compared with oil/paper insulated HVDC cables.
In this Industrial Ph.D. project new cable insulating materials will be characterized both mechanically and electrically, with the main focus on the electrical properties. An important part of the electrical characterisation will be to measure the space charges in the insulation under different conditions.
The space-charge measurement is possible due to improvement in the measuring technique during recent years, at the Technical University of Denmark (DTU) among other places. It is thereby possible to measure the space-charge density in cable insulation and, from the measurements of space charges, to improve the build-up for optimizing the DC conditions in the insulation material.
The space charges and conductivity will be measured with existing equipment. In this project the space charges will be measured either with the Pulsed Electro-Acoustic method (PEA) or the Laser-Induced-Pressure-Plus method (LIPP). The results will be important for the understanding of which mechanisms the electric properties depend on.
The Industrial Ph.D. Project will continue developing the know-how in the area of DC cable insulation, and make it possible to increase the national as well as the international work on DC cable insulation.
Co-operation and Supervisor:
This Industrial PhD Project is carried out by Jesper Hjerrild in co-operation with NKT Cables A/S, NKT Research Center A/S
and the Department of Electric Power Engineering at DTU, with Associate Professor Joachim Holbøll as supervisor.
M.Sc.-programme:
Jesper Hjerrild is Master of Science in Power Engineering graduated at the department of Electric Power Engineering at DTU. During his education the main focus has been on Electric Power Systems and Experimental Electric Power Engineering. His graduate project was building of equipment, which makes it possible to measure space charge in power cables based on the LIPP method.
MSc description (danish)
Link
Further information
• ORBIT database