This paper investigates the relationship between the charge Qi of the first impulse corona and the associated inception voltage Ui for a 1m point–plane airgap submitted to impulse voltages. Experimental studies under both polarities are reported; the Qi–Ui characteristics obtained allow empirical quadratic relationships between these two quantities to be derived. A physical interpretation is proposed by considering the established characteristics of the first impulse corona. The Gauss and Amp`ere–Maxwell laws can be applied and the quadratic Qi–Ui relationship is justified by the present model.     «

This paper investigates the relationship between the charge Qi of the first impulse corona and the associated inception voltage Ui for a 1m point–plane airgap submitted to impulse voltages. Experimental studies under both polarities are reported; the Qi–Ui characteristics obtained allow empirical quadratic relationships between these two quantities to be derived. A physical interpretation is proposed by considering the established characteristics of the first impulse corona. The Gauss and...     »