Degradation Behavior of Metallized Film Capacitors: A Review

Metallized film capacitors are widely used in power electronics due to their brilliant electrical properties. However, the more stringent operating conditions (e.g., temperature, humidity, current, voltage) brought about by the development of the energy industry may significantly impact capacitor reliability. This paper provides an elaborate description of the composition of metallized film capacitors. Then, the types of dielectric materials, metallization methods, and sprayed end forms are discussed in detail. In addition, various degradation modes are reviewed, including the degradation of electrode metallization with dielectric layers under high ambient temperature and high humidity conditions, the effect of over-voltage on reliability, and the aging of sprayed ends under pulsed current.