Study on estimate approach of flashover voltage in oil gap under non-uniform field

An estimate method of flashover voltage in oil gap under non-uniform field is proposed. The method is deduced on the base of the n power law for V-d characteristic confirmed experimentally under uniform field. The method developed in this paper enables the V-d characteristics of oil gaps under various electric field distribution to be calculated. The comparison of calculation with experiments in corner-plane, rod-rod, rod-plane electrode and coil insulation models of transformer are summarized. The V-d characteristics obtained by this method agree approximately with experimental results.