Dependence of Self-Healing Arc on Metal Vaporization Contributions for Metallized Film Capacitor

Metallized film capacitor (MFC) bears high operation-reliability under high electric field, owing to the unique property of self-healing (SH). The SH process is always accompanied by the growth and extinction of arc, together with the evaporation of metal electrode. This paper established the three equivalent circuit models to visualize the abstract SH process. Moreover, a theoretical model based on charge quantity was constructed to study the dependence of SH arc on metal vaporization contributions for MFC under low electric field. The consequence of model and experiment shows that the aluminum vapor is ionized in the SH process that constantly provides charge to the arc. Moreover, the demetallized zone area is proportional to the voltage drop in the condition of breakdown of 1 layer of biaxially oriented polypropylene (BOPP) and evaporation of two layers of metal electrodes above and below it.