Ab initio molecular dynamics of insulating paper: Mechanism of insulating paper cellobiose cracking at transient high temperature

Oil-impregnated paper is the most widely used insulating material for power transformers. Power transformers inevitably generate a lot of heat during operation. Among them, thermal aging is one of the main forms of aging for insulating paper. In this study, the ab initio molecular dynamics method based on the density functional theory is used to simulate the cracking mechanism of cellobiose under transient high temperature. The results show that the cellobiose is relatively stable at 343 K, the motility of the cellobiose is enhanced at 1,800 K, the cellobiose starts to decompose at 2,400 K, and new characteristic products are formed at 3,000 K. The characteristic products include CO, H2O, CH3OH, H2, and CH4. These characteristic products can represent the degree of cracking of insulating paper. Therefore, it is necessary to explore the mechanism of cracking of insulating paper caused by transient high temperature.