Partial discharge energy and electrical tree volume degraded in epoxy resin

Electrical trees are hollow artifacts resembling botanical trees generated in high electrical fields, and are a form of polymeric insulation degradation. Most models assume partial discharges, which accompany tree growth, are the cause of material degradation, and so understanding the energy associated with discharges and the energy of vaporization of the material chemical constituents is critical. In this study the volume of trees has been determined through an X-ray Computed Tomography technique, and the energy of discharges by directly measuring PD activity during tree growth. It is shown that approximately 9×105 μm3 of material is evaporated per electrical Joule of energy, representing 7% efficiency in the conversion process.