Experimental work on epoxy resin samples regarding small discharges and the existence of charging effects below inception voltage

In this paper, some results are presented on experiments concerning partial discharges (PD) behavior of epoxy resin samples. The main idea is to see whether a sample with PD at its inception voltage, still presents some tendency to charging effects below inception. An effort is being made to relate the present work with previous publications on the same main idea. The experiment arrangement is three layers of epoxy resin with a void in middle layer. Different level voltages under inception voltage are applied to the arrangement and different PD waves are registered under different level voltages. To make sure that the tendency to charging effects below inception, infrared spectrum analysis is also conducted and the result is content to clarify our objective.