Modeling of Electrical Tree Propagation in the Presence of Voids in Epoxy Resin

Electrical treeing is one of the principal routes to dielectric failure in solid insulating materials. Researchers around the world are still struggling to formulate acceptable theories that explain the processes involved. Tree initiation and growth require localized field-enhancement that results in material erosion and degradation, and consequent partial discharges within the tree tubules. Polymeric dielectrics include voids in the base matrix due to limitations in the manufacturing process. These can enhance the tree initiation and growth of tree structures. In this work, an attempt has been made to understand qualitatively how the presence of voids affects tree growth. Experiments were performed with voids of different sizes and at different locations. Computer simulations were carried out to understand the experimental results in terms of space charge fields produced in the vicinity of a void as well as in the bulk dielectric from hv needle electrode