Furfural is a valuable indicator for evaluating the aging of transformer paper insulation. However, furfural will degrade under the effect of oxygen dominated in the aging process of oil-paper insulation. Considering that the degradation of furfural in oil will interfere with the accuracy of the aging evaluation results. Therefore, it is of great significance to study the effect mechanism of oxygen on the degradation of furfural from the level of molecular simulation and experiments. In this paper, the molecular dynamics method based on reaction force field (ReaxFF) is used to simulate the degradation process of furfural in insulating oil under the influence of oxygen. A model composed of insulating oil molecules, furfural, and oxygen is established. Subsequently, accelerated thermal aging tests are performed on insulating oils containing an initial concentration of 10 mg/L furfural in aerobic and anaerobic environments, respectively. Then, the furfural content in the sampled oils at different aging stages is measured. The simulation results show that the number of furfural molecules is significantly reduced under the action of oxygen molecules, which indicates that furfural is degraded and a certain amount of furoic acid is generated. Laboratory measurements also confirmed this phenomenon. This work explains the effect of oxygen on the degradation of furfural in transformer oil from the molecular dynamics level, and provides a theoretical basis for improving the accuracy of transformer aging assessment based on furfural indicators.

Transformer,Insulation,Furfural,Oxygen,Molecular Dynamics Simulation