Measurement and analysis of insulation resistance of metallized polypropylene film capacitor under high electric field

Metallized polypropylene film capacitor (MPPFC) has characteristics of high energy density and high reliability due to its self-healing capability. The insulation resistance (IR) of capacitor applies a leakage path through the dielectric and would exert negative influences on the efficiency of the pulsed power system. This paper mainly concentrates on the leakage phenomenon in MPPFC by the measurement and analysis of IR. The results indicate that the time constant called equivalent IR is extremely sensitive to electric fields and temperatures. Finally theoretical calculation of equivalent IR based on electrical conduction is carried out. And the calculation shows that equivalent IR value is influenced by the coefficient of Poole-Frenkel effect.