Making use of Rizk’s model of continuous leader inception and breakdown of long air gaps, the calculation formula for 50% flashover voltage of the rod–plane gap is obtained by applying the switching impulse voltage with the critical wavefront time under standard meteorological conditions, as expr...
B Formulae Here we summarize the formulae appeared in the main text and supplement details of derivations. We start from nine dimension plus three compact dimensions. We use the metric in the string frame (5.4), which obtained from the metric (3.2) after the rescal- ing (3.33). The ...