Lifetime estimation of high-temperature high-voltage polymer film capacitor based on capacitance loss

Abstract Under steady voltage and temperature stresses, capacitance can be considered as a reliable aging indicator since in such conditions, metallized polymer film capacitors suffer from the gradual loss of their electrode surface. Empirical laws are most often considered to predict the operating lifetime of energy storage systems under specific environmental conditions. However, expected lifetimes in this case are not able to track the capacitors degradation with time. In this paper, a special capacitance degradation model is proposed based on several experimental aging tests at different temperatures and voltage stresses. A total of 30 capacitors using a novel high-voltage high-temperature (HVHT) polymer as dielectric have been studied and compared to validate the proposed law. This novel HVHT polymer offers significant improvements upon the standard dielectric materials, providing excellent self-healing capability with an enhanced energy density.