The effect of interface modification on electrical tree growth and breakdown of epoxy resin

This study investigates the effect of an interface on the lifetime of epoxy resin samples and the growth characteristics of electrical trees. Six sample types are presented; all having been prepared in the point-plane configuration using a needle -with a tip radius of 3μm- as the HV electrode. Most were molded in two parts producing an interface perpendicular to the field direction at the centre of the sample. Tests were carried out at 13 kV rms until sample breakdown occurred and sample images were taken at fixed one minute intervals during the test period. Results show that the interface modification affects electrical tree characteristics and improves the time to breakdown of the epoxy resin tested.