Aging analysis of metalized film capacitors

This paper summarizes the results of metalized film capacitor analysis made on capacitors of different manufacturers and types. The capacitors were operated for about 12 years in a power supply and served as a reactance to reduce the supply voltage without losing active energy. The capacitors were long stressed by continuous presence of voltage and current pulses. The measured results are reviewed and the causes of excessive aging of capacitors, including photographs and X-ray analysis of defects are discussed.