Lifting Field of Free Conducting Particles in Compressed SF6 with Dielectric Coated Electrodes

The lifting field of a free conducting particle (FCP) situated on a dielectric coated electrode in compressed SF6 gas is calculated based on two different particle charging mechanisms-partial discharges occurring in the gas surrounding the particle and charge conduction through the dielectric coating. Calculated values are compared with experimental results obtained for different thicknesses of anodized (Al203) coatings and at different gas pressures. It is suggested that at lower pressures a partial discharge mechanism is predominant whereas at higher pressures a charge conduction mechanism is predominant.