Investigating the influence of temperature and DC electric field on the electric conduction of oil impregnated paper insulation

Electric conduction of oil impregnated paper under different temperatures and different DC electric fields has significant influences on the insulation structure design of converter transformer. This paper focuses on the influence of temperature and DC Electric Field on the electric Conduction of oil impregnated paper insulation, as well as conduction mechanism of oil impregnated paper through the high-field conduction experiments. It is concluded that a raise in temperature and DC electric field leads to the higher conductivity of the oil impregnated paper sample. The activation energy representing conduction barrier height was obtained. Moreover, the mechanism of electric conduction in oil impregnated paper was analyzed, which confirms the hopping conduction model instead of space charge limited current theory. Based on the upper statement, the parameters like the electronic hopping distance δ and the parameter j0 were obtained and we explored the conductivity σ changing along with the electric field under different temperatures.