On the failure mechanism of metallized polypropylene pulsecapacitors

摘要

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