Charge-voltage relation of the corona discharge in point-to-plane and coaxial electrode configurations

On the one hand, an empirical quadratic relationship between the charge Q_i of the first impulse corona and the associated inception voltage U_i has been recently proposed for a 1m point-plane airgap submitted to impulse voltages. On the other hand, different models have been proposed to evaluate that relation for coaxial geometries also submitted to impulse voltages. The aim of this paper is to compare the two charge-voltage relations and to discuss how the assumptions made for one configuration can be exported to the other electrode geometry.