Electrical treeing in composite materials

The geometric properties of electric tree structures affect the propagation rate, presenting a non-trivial dependence as a function of time and voltag e. The cluster forms from an open branch to a compact bush or ball that can make connections between opposite electrodes at sufficiently high voltages . Consequently, a breakdown process occurs. The proposed model of electrica l tree development is based on a solution of the Laplace equations for a qu asi self-similar structure. Such a structure appears near the point of perc olation transition in a porous or composite dielectric. Some mechanisms of local puncture are considered. The function of probability of bond transiti on from a low-conductivity state to a high-conductivity state is a function of the applied field, the temperature, and so on. Under different conditio ns, one factor predominates and provides the main influence on the amount a nd location of space-charge trapping. The aim of this research was to evalu ate a correlation between the physical and abstract mathematical parameters concluded in the model picture of a dielectric breakdown process and to ex plain the concentration and scaling dependencies in a composite dielectric.