Surface flashover characteristics and optical emission analysis of nano particle cast epoxy resin

Surface flashover is one of the major issues in electrical insulation in power systems operating either in space (vacuum or partial vacuum) or atmospheric (earth-bound) environments. Development of new and advanced materials to be used in power systems requires extensive studies on electrical insulation characteristics of these materials before they can be used in commercial systems. In this paper, we present experimental results of surface flashover characteristics in partial vacuum of epoxy resin and epoxy resin cast with powdered Al₂O₃. The flashover studies were conducted using DC and AC signals separately. Surface flashover voltage and current wave forms of the samples and light emission wave form and video images during the breakdown were recorded. Optical data collected by a video camera along with the PMT light emission data are analyzed and the analysis results of the optical emission characteristics of surface flashover are presented. The samples used in the experiments were produced by using either epoxy resin of known properties or by mixing known quantities of Al₂O₃ with epoxy. The electrode material placed over the dielectric samples was copper.