Transient finite element computation of the temperature rise in metallized film capacitor end connections caused by underdamped discharge

Loss of end connection integrity is the most common failure mode for metallized film capacitors under pulse discharge conditions as a result of electrothermal effects associated with the intermittent nature of the contact between the sprayed metal end connection and the edge of the capacitor film. In this paper, the temperature rise as a result of varying polarity reversal is analyzed through the use of transient finite element analysis which shows that polarity reversal is unlikely to cause greater damage to the end connection than discharge without polarity reversal. This suggests that the adverse effect of polarity reversal is dielectric or electrical, but not electrothermal in nature.