Dielectric Coatings-Effect on Breakdown and Particle Movement in Gitl Systems

Contamination by metallic particles in campressed gas insulated power transnission (GITL) equipment is commonly encountered. Free conducting particles, depending upon their shape, size and location, may significantly impair the insulation strength of GITL apparatus. Experiments conducted in the authors' laboratory, indicate that dielectric coatings on electrodes not only improve gaseous insulation but also raise the voltage necessary for initiating conducting particle movement in GITL apparatus. The paper summarizes the results of a ten year investigation into the usefulness of dielectric coatings in GITL apparatus in the presence of metallic contaminants.