In order to understand the evolution of charge accumulation and dissipation characteristics of Nomex paper during thermal aging progress

an experiment system of accelerated thermal aging was designed and the samples were prepared. The samples in different aging circles were charged by the needle plate model and then the surface charge decay progress was measured. The trap distribution of Nomex paper was calculated according to the surface potential attenuation curve. The results show that the initial surface potential distribution of insulation paper remains bell shaped during its decay. The volume conductivity and the surface conductivity contribute to the charge decay. The total amount of accumulated charge tends to decrease at first and then increase with the aging of insulation paper. In addition

the conduction through the surface of the unaged paper is the main reason for charge decay

the dissipation rate of positive charge and negative charge increase with the aging time for different reasons. The theoretical support was provided to understand the influence of thermal aging on charge transport characteristics of oil-paper insulation.