Developing an experimental method for a cavity PD based life model

Despite the large amount of activities undertaken in both the area of partial discharge (PD) in cavities and polymeric insulation degradation, degradation of polymeric insulation induced by cavity PD remains a subject where there are more questions than answers. In this paper, an experimental approach is discussed which has the aim of allowing observation of degradation induced by cavity PD. A model based on electron scattering mechanisms in both the cavity gas gap and polymeric insulation is proposed. From observing electron avalanche behavior and its damage mechanisms to the insulation, it may be possible to develop approaches that improve our ability to estimate remaining life of polymeric insulation systems in high voltage plant.