Electrical Performance of Metallized Dielectric Films with Different Sheet Resistances in Plastic Film Capacitors

Metallized film capacitors (MFCs) are widely used as energy storage components in high‐voltage power electronic systems owing to their excellent self‐healing capability, high reliability, and low dielectric loss. Sheet resistance—a key parameter of metallized dielectric films—determines the internal resistance and self‐healing characteristics of Plastic film capacitors. Therefore, understanding the influence of sheet resistance on overall capacitor performance is essential. In this study, we combined experimental measurements and simulations to investigate the relationship between sheet resistance and metal layer thickness, and to elucidate how sheet resistance (5–30 Ω/□) affects capacitor performance. To elucidate the evolution of the internal electrical behavior of the capacitor during operation, breakdown, ESR, and charge–discharge tests were conducted, supplemented by finite element simulation. The results show that sheet resistance significantly affects the capacitor's cycle durability at rated voltage and its breakdown risk at limiting voltage by modulating the self‐healing energy and the Joule heating effect caused by internal ESR.