The degradation properties in the corona charged epoxy composites by TSC measurement

Corona degradation phenomena of epoxy composites to be used for transformers were studied. A formation of corona electrets was first observed by applying high voltages to five different kinds of specimens for a given mixing rate. Thermally stimulated currents (TSC) were measured in a temperature range of -160/spl sim/200(/spl deg/C). Carrier behaviour and its origin in epoxy composites was examined. Various effects of corona degradation on epoxy composites were also discussed.