A study of oil impregnated pressboard insulation based on ester fluids for an application in HVDC insulation systems

Ester-based insulation fluids are increasingly used in high-voltage insulation systems. The reasons for this are the advantages in the area of ecological compatibility and resource-saving provision. The use of ester-based insulation fluids in HVDC equipment is new. For this purpose basic investigations are carried out in the form of conductivity investigations for various insulation barrier systems. In addition, a mineral oil serves as a reference oil for estimating existing insights. The results show the influence of the ester-based insulating liquids on the DC conductivity of pressboard barriers and mixed insulations.