Dissolved Gas Diffusion Coefficients and Properties in Camellia Insulating Oil

As a new environmentally friendly liquid dielectric material, vegetable insulating oil has been used in oil-filled transformers more and more widely. In transformers, ageing, overheating faults, and discharge faults cause the decomposition of insulating oil and insulating paper, and then cause dissolved gases in the oil. These transformer fault diagnosis and prediction can be realized by Dissolved Gas-in-oil Analysis (DGA) method, which is closely related to the diffusion process of gas in oil. However, few research involves diffusion processes of dissolved gases and thus no effective DGA method for vegetable insulating oil-filled transformers has been proposed. In this paper, in order to have a better understanding for vegetable oil transformer fault process and improve the effective of DGA method as theoretic support for vegetable oil transformers, the research of diffusion properties and mechanism of characteristic gases in camellia insulating oil is very meaningful. The molecular dynamics simulation based on polymer consistent force field (PCFF) was adopted to analyze diffusion processes of characteristic gases. Impacts of gas species as well as temperatures for molecular diffusion coefficients were studied. The result provides theoretic support for fault condition assessment and operating maintenance of vegetable insulating oil-filled transformers, and also has great theoretical reference value for ensuring safe operation of vegetable insulating oil-filled transformers.