Dissolved gas analysis in transformer oil using Sb-doped graphene: A DFT study

Abstract

In order to improve the reliability of the transformer, reduce the maintenance cost of the transformer, online detection technology of transformer oil dissolved gases (H2, C2H2 and CH4) has become more important. Quick and accurate fault location is the research focus of this technology. In this paper, based on first principles density functional theory (DFT), the best Sb doping position was discussed, and adsorption systems of H2, C2H2 and CH4 on intrinsic graphene and Sb-doped graphene were built. The adsorption energy, charge transfer, bandgap, the energy of lowest unoccupied molecular orbital (LUMO), the energy of highest occupied molecular orbital (HOMO) and the total and partial density of states (DOS) of these adsorption systems were analyzed. The results showed that T doping site (Sb-CT) on the surface of graphene is the most stable site. And the intrinsic graphene has better adsorption and gas sensitivity to C2H2. Compared with H2, Sb-CT doped graphene has better sensing properties to C2H2 and CH4. It illustrates that Sb-doped graphene can be used in the overheated fault detection of the transformer.