Analysis on the thermal stability of the amorphous region in insulation paper

The molecular simulation at atomic level is helpful for exploring and analyzing the microscopic mechanism of various complex phenomenon of thermal stability in the transformer insulation paper. Therefore, by using the molecular dynamics (MD) method and density functional theory (DFT), this paper established the amorphous region model of cellulose in insulation paper, and analyzed its thermal stability. The force field used in the model optimization and the molecular dynamics simulation is the PCFF (Polymer Consistent Forcefield), which is suitable for the carbohydrate. After the analysis of the simulation results, it is concluded that the mechanical parameter of amorphous region hardly changed under different temperature, which indicated that operating temperature of transformer has little influence on the mechanical parameter. As the temperature increased, the molecular activities in cellulose became more active, the hydrogen bond was partly damaged and the stability in the amorphous region weakened gradually.