Effect of pulse discharge current on lifetime performance of metallized polypropylene film capacitor

Summary form only given. Metallized polypropylene film capacitor (MPPFC) is one of the key components in pulsed power system. In order to increase the reliability of the power source equipment, the lifetime of the capacitor must be extended. Self-healing is one of the main features of MPPFC. With the ongoing self healing, capacitance will reduce. If capacitance decreases to 5%, the capacitor is defined to life-ending. Many tests have demonstrated that lifetime performance of capacitor is closely related to some operational factors such as electric field, temperature, and pulse repetition rate and so on. But the effect of pulse discharge current on lifetime has not been thoroughly studied. The aim of this paper is to study the pulse discharge current performance of MPPFC. End connection peak current density (I_d) and current reversal coefficient (β) are two critical parameters affecting the lifetime of the MPPFC. Experiments are designed to study the lifetime performance under different I_d and β. The results show that the lifetime of capacitor is extremely sensitive to β and less sensitive to Id if the Id is less than a certain value. The results also reveal a kind of sudden capacitance drop phenomenon, which indicates that the probability of the sudden capacitance drop increases with the I_d. And as the conclusion, the paper gives empirically derived life-scaling equations of I_d and β.