Calculation of corona onset and breakdown voltage in short point-to-plane air gaps

Abstract

A method of calculation of corona-onset and breakdown voltage in short point-to-plane air gaps is proposed in this paper. This method is based on the assumption that for corona (for negative voltage on the point electrode) or breakdown (for positive voltage on the point electrode) to occur, the energy input into the gap due to the formation of an electron avalanche should reach a critical value. The critical value of the energy is calculated numerically from the known experimental value of the breakdown voltage in uniform field. The corona-onset and breakdown voltages calculated from the proposed method are compared with other existing methods as well as with experimental results.