ARAMETRIC AND CATASTROPHIC FAILURE OF METALLIZED FILM CAPACITORS IN ULTIMATE LOAD OPERATION CONDITIONS

n this paper the automated ramp voltage test method for metallized film capacitors was suggested. This method was used to investigate the causes of capacitors failure under high electric load. For this purpose, experimental setup and software for experimental data processing were developed. The experimental investigation method was based on high voltage testing of different metallized film capacitor types. It was found that in the case of high electric load, capacitors failure is related to dielectric resistance decreasing due to multiple breakdown events. The conditions of parametric and catastrophic failures of the tested capacitors were revealed. The suggested test method also allows “soft” treatment of metallized film capacitors.