The effect of material interfaces on electrical tree growth and breakdown time of epoxy resin

This study investigates the effect of barriers and interfaces on the lifetime of epoxy resin samples, as well as the growth characteristics of electrical trees. Four sample types are presented; all having been prepared in the point-plane configuration using a hypodermic needle as the HV electrode. Tests were carried out at 13 kV rms and sample images were taken at fixed one minute intervals during the test period. Results show that the incorporation of a barrier improves the time to breakdown of the epoxy resin tested. The inclusion of a major void defect did not accelerate failure of a sample which included an effective barrier.