Modeling the Breakdown of Dielectrics Loaded With Conducting Particles

This study addresses the electrical breakdown of dielectrics loaded with randomly dispersed conducting particles. A simple stochastic breakdown model is proposed and used to provide information on the tree structure and dielectric breakdown strength. Parametric simulations suggest an important role of the particle fraction and microstructure (regular versus aggregated) on the breakdown strength while the particle size and size dispersity have limited effects. The obtained results have been recast in terms of geometrical parameters describing the particle structure and the minimum-gap path (path having the shortest length of dielectrics) is found to correlate quite well with numerical results. This suggests that simple geometrical quantities are relevant to provide quantitative predictions of breakdown strength for such materials.