Empirical formula for the frequency breakdown voltage of C4F7N/CO2 gas mixtures

In order to obtain an empirical formula for calculating the insulation performance of C4F7N/CO2 gas mixtures, and to facilitate the insulation design, pre-testing and operation and maintenance of C4F7N/CO2 gas mixtures, this paper investigates the variation characteristics of the insulation performance of gas mixtures with the mixture concentration, air pressure and electric field inhomogeneity coefficient as parameters, using experimental and currently reported data related to the industrial frequency breakdown of C4F7N/CO2 gas mixtures. The data are then fitted to a complete empirical equation to predict the actual insulation capacity of the gas mixture.