On the failure mechanism of metallized polypropylene pulse capacitors

Metallized pulse capacitors has gained wider and wider usage because of their unique “self-healing” character. Their failure mechanism has many differences from film/foil capacitors. Experiments were carried out on a number of metallized polypropylene pulse capacitors in order to understand their failure mechanism better. Using some model Metallized Polypropylene capacitors manufactured under different production parameters, it is observed that the failure mechanism is influenced by thermal disposal temperature, vapor deposited metal, electrode-end spray condition, and current density of electrode-end. Breakdown, electrode-end degradation and excessive capacitance loss mainly cause the failure of metallized polypropylene pulse capacitors under high electric stress