Electric Field and Temperature Dependence of Electrical Conductivity in Biaxially Oriented Polypropylene Films

In pulsed power systems, metallized film capacitors facilitate the operation of the film with a relatively small margin to its dc breakdown strength. Electrical conduction in metallized biaxially oriented polypropylene (BOPP) film may result in the leakage in high energy density capacitors and thus the reduction of the energy efficiency. This paper investigates the mechanism of the electric field and temperature dependence of electrical conduction in the BOPP film capacitor. A proposed model for the electrical conductivity takes into consideration both the Poole-Frenkel effect and field-enhanced carrier mobility. Experiments are performed to measure the electrical conductivity of the BOPP film at different electric fields and temperatures.