Surface Flashover Characteristics of Nano Particle Cast EPOXY Resin

Surface flashover across solid insulators in vacuum has found applications in the area of space power systems. One scenario where surface flashover in vacuum can be a problem in space power systems is a spacecraft operating in geosynchronous orbit (GEO) or low earth orbit (LEO) interacts with the local space environment resulting in the differential charging of the spacecraft to electrical potentials of many hundreds to few thousand volts. When this charging reaches a critical value, surface flashover on the solid dielectric insulator may occur, resulting in loss of high voltage isolation and damage to the space power systems on board. Similarly, surface flashover can also occur across insulators in the utility power system in atmospheric pressures as well. In general, random emission of a small number of electrons at the cathode results in positive charging of the dielectric surface at the triple junction, thus initiating surface flashover across the dielectric. In this paper, we present experimental results of surface flashover characteristics of epoxy resin and epoxy resin cast with powdered Al₂O₃. 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. The flashover studies were conducted using DC and AC signals separately, and surface flashover voltage characteristics and the breakdown voltage wave forms of samples were determined.