The influence of barriers on the penetration of solid insulation by discharges

摘要

This work investigates possible correlations between electrical discharge tree growth and the mechanical characteristics and strain associated with additives in resin based composite insulation. It is shown that the resistance presented by a barrier to tree growth is determined by fracture toughness, thermal resistance and work of adhesion. A high work of adhesion prevents interfacial tracking but, as importantly, leads to internal strain which, if compressive, substantially enhances tree resistance.