Fabrication of Permittivity Graded Materials for Reducing Electric Stress on Electrode Surface

For the size reduction of electric power equipment, an increase of electric field stress around solid insulators is carefully to be considered. The application of FGM (Functionally Graded Materials) with spatial distribution of dielectric permittivity (epsiv-FGM) will be an effective solution for this concern. In this paper, we investigated the fabrication techniques of epsiv-FGM for reducing the electric stress on the electrode surface with contact to the solid insulator, which was one of the factors dominating a long-term insulating property of the spacer. Firstly, we carried out numerical simulation to investigate the reduction of the electric stress by U shape permittivity distribution. Secondly, we investigated the fabrication feasibility of epsiv-FGM with the U shape distribution. Finally, we could confirm the significant effect of application to solid dielectrics in electric power equipment.