Electric Conductivity, Dielectric Losses and Breakdown of Solid and Liquid High Voltage Insulation

The following main topics are covered: -Electrical conduction in glass, oil and other amorphous dielectrics due to movement of ions and particles. -Electronic conduction in partly crystalline solid materials, focusing on influense of applied electric field and temperature. Schottky, Poole-Frenkel and Spacecharge limited currents are particularly discussed. -Physical description of Permittivity and dielectric loss with respect to Clausius Mosottis equations, the Debye relaxation, Garton effects,ion and interface polarisation as basis for frequency and time domain description of dielectric responce. -Electric breakdown of solid and liquid dielectrics, including statistical methods for evaluation of breakdown data. -The course will focus on description of mechanisms regarding the commonly used insulating materials: Polymers, oil/paper and glass.

The purpose of the course is to give an indepth review of limiting factors regarding application of different dielectric materials in High voltage apparatus. Knowledge: After completing the course, the student shall have: - a physical understanding of mechanisms of electrical conduction - a physical understanding of permittivity and dielectric loss - a physical understanding of mechanisms of electric breakdown - knowledge about methods for statistical evaluation of breakdown data Skills: After completing the course, the student shall be able to: - plan experimental investigations and interprete results with respect to physical mechanisms of electrical conduction,-loss and brakdown - develope and design new high voltage insulation systems for AC and DC power apparatus

Lectures / Seminars/ Exercises. The course will be given in English if necessary. The course is given every second year.