Predominance of joule heating effect on the electrode destruction due to a self-healing of a metallized film

摘要

Capacitors made of metallized films of plastics suffer partial discharge named self-healing. This disruptive phenomenon is described as the spontaneous extinction of an electrical arc due to the destruction of the electrodes during the process. In this paper we modelize self-healing by a cylindrical arc that strikes a thin metallic surface. The related pulse of current, limited by the electrode resistance, induces the vaporization of the metal by joule heating. The volume of plasma formed increases with time and we found that the density of energy in the plasma decreases under a critical value such the plasma cannot sustained and then extinguishes. We will describe this model and compare it to experimental data.