Effect of temperature on surface charge accumulation and decay of polypropylene film under DC and pulse voltages

Polypropylene (PP) is generally applied in the dielectric material of Film capacitors, which faces temperature rise and multiple electrical stresses. The accumulation of charge on PP film may induce discharge causing energy loss and accelerating electrical ageing. This paper is dedicated to research the influence of temperature and different voltage waveforms on the surface charge trap characteristics of PP film. The specimen was corona charged with needle-plate electrodes by combination of DC and pulse voltage. The surface potential decay was conducted ad different temperature. The results demonstrate that temperature rise can obviously enhance detrapping of the surface charge in deep traps, hence accelerating the charge dissipation. Under multi-stress of DC and pulse voltage, the surface charge accumulation is influenced by temperature due to its impact on surface charge coupling. Meanwhile, the dissipation of surface charge becomes complicated with coupling procedure as well, in which the electrical field, trap level and density illustrate inconsistency with the decay under various temperatures.