Sensitivity analysis of leader channel models used in long air gap positive discharge modelling

Leader models used in electrical discharge simulation have been proposed in theoretical works by different authors. Their application can be found in the study of lightning upward connecting leaders or long air gap laboratory testing, and can be considered engineering or physical according to their detail level. Based on simplifications and assumptions, these models are capable of predicting the 50% breakdown voltage for certain electrode arrangements, time evolution of physical phenomena like particle densities, temperatures, electric fields, leader and streamer progress, among others. An important parameter in a leader model is the potential distribution along the channel as it propagates. In present work, we compare an engineering and a physical leader model against experimental data recorded while testing a rod-to-plane 10 m gap with switching-like voltage impulse. A sensitivity analysis was done with some basic input parameters of two leader models in order to compare the outcome for different cases. The results showed a strong dependence of the leader channel evolution with the assumed constant average potential gradient used in most of the leader models.