Solid/Gaseous Insulation Systems for Compact HVDC Solutions

Gas insulated systems for use under high direct voltage (DC-GIS) are investigated with focus on electric field distribution in the system and dielectric strength of alternative gas mixtures. Calculation of the transient field distribution is based on permittivity as well as bulk and surface conductivity of the insulating materials involved, taking into consideration their dependence on temperature and electric field strength. For insulating gases, a simulation model that takes into account the behavior of charge carriers in the gas has been developed and verified experimentally. For solids, the characteristic properties are determined at the relevant stress factors. The influence of antimony doped tin oxide based functional fillers on solid insulators is studied experimentally, and field…