Self-Healing Characteristics of Metallized Film Capacitors Based on Coupling Capacitance Modulation of Charge Injection Amount

Metallized film capacitors(MFCs) are widely used in electromagnetic ejection and flexible DC transmission systems due to their high stability and reliability. In practical engineering applications, the self-healing performance of MFCs is affected by the different amounts of injected charges at the same voltage, but their specific self-healing behaviors under different amounts of injected charges are still unclear. This study focuses on the differences between the self-healing properties of MFCs under variations in charge injection. The results show that the self-healing performance of MFCs decreases with the increase of the charge injection amount(increase in capacitance of coupling capacitor). The initial self-healing voltages of MFCs at high charge injection levels(large capacitance coupling capacitors) are significantly lower than those at low charge injection levels(small capacitance coupling capacitors). Additionally, the capacitor's self-healing energy and the metal electrode evaporation area increase with the increase of charge injection. This study provides strong guidance for the long-term stable operation of MFCs under the variation of charge injection amount.