Predicting the Electric Strength of Proposed Sf6 Replacement Gases by Means of Density Functional Theory

We computationally estimate the electric strength (ES) and the boiling point (TB) of 2611 carbonyl compounds. Namely we systematically analyze the groups of hydrofluoro-ketones, -aldehydes and acyl fluorides as well as perfluoro-ketones and – aldehydes. The elemental composition is restricted to solely hydrogen, fluorine, a single oxygen atom and 3 to 5 carbon atoms. Our method is based on the strong correlations between the ES of electronegative gases and certain predictors [1]. Predictors are simple functions of molecular properties, which are calculated ab-initio by means of density functional theory (DFT). We use the same method to estimate TB of the gas samples [1]. Recently certain C5and C6-perfluoroketones were proposed as dielectric insulation medium in electrical power system equipment [2-4]. We compare our calculated values of the ES and TB of these compounds with other carbonyl compounds. We detect influence of the chemical structure on the ES and TB of a species and we identify other hydroand per-fluoro carbonyl compounds of similar or even better insulation properties.