Tracking and fracturing in epoxy resin due to partial discharges in artificial voids

A void geometry has been developed to generate partial discharge activity and initiate electrical tracking degradation in laboratory insulation systems, providing an alternative to the needle-plane configuration. Reproducible voids were successfully manufactured in epoxy resin at the surface of a rod electrode, creating an enhanced electric field within the voids. Partial discharge measurements have been used to understand the role of discharges in the progression of degradation in the void sample. Fractures formed due to mechanical stresses are observed and investigated by venting the void. Finite element analysis is used to explain damage patterns seen in the epoxy resin samples including a broad region of tracking formation at an associated interface.