Insulating materials characterization for the development of MV/HV DC equipment

Interests for MV and HV DC equipment are increasing due to the advantages of DC over AC in long distance power transmission. In these equipment different insulating materials, including gas and solid, coexist in close contact with each other. This paper shows the importance of material characterization in order to ensure correct estimation of the electric field distribution and reliable design of equipment. Different test benches are presented for a complete characterization of gas and solid insulating materials with the ability to study the effect of electric field, temperature, gas humidity and gas type on conduction behavior.