Partial discharge stressing of epoxy resin surfaces

An understanding of the degradation mechanisms of solid dielectrics under the action of partial discharge stressing, coupled to a characterisation of the various species and their prevalence under different conditions of stressing, will enable both the development of new insulating systems for power plants in the future and new diagnostic techniques to detect degradation in existing systems. This paper reports experimental work undertaken to study the changes brought about in an insulating resin formed from a diglyceride of bisphenol A cross-linked by phthalic anhydride, a common epoxy resin