Materials characterization and performance of insulation system of HVDC switching device
The report summarizes the research activities related to insulation systems of HVDC apparatuses. The obtained experimental data on electric resistivities and permittivities of materials constituting the insulation system are analyzed. The measurements of surface potential distributions on HVDC insulator mock-up and the results of its impulse testing are discussed. The developed methodology for combined LI & dc tests and the obtained results are introduced. An analysis of static and transient (including impulse conditions and polarity reversal) electric fields in the device is presented.