Effect of the polarity-gap interaction on the tendency of the electrical discharge paths in air when the lightning impulse and direct voltages are applied

This paper presents the experimental results of a research concerning the effect of the polarity-gap interaction on the distribution of the impact points produced by electrical discharges in air when the lightning impulse and direct voltages in both polarities to a point-plane arrangement are applied. The statistical analysis of these experimental results allowed to describe the distribution of the impact mean points so as to evaluate the tendency of the electrical discharge paths. Considering the experimental results already mentioned, the following results based on the statistical analysis were obtained: For the clearances between the electrodes studied from 0,06 to 1,25 meters in the case of the impulse voltage, the transition interval from 0,08 to 0,1 meters was identified. For the clearances between the electrodes studied from 0,04 to 0,2 meters in the case of the direct voltage, the transition interval from 0,06 to 0,08 meters was also identified. In such intervals the change from a predischarge mechanism to another occurs, as well as the inversion in the path tendency. The authors consider that it is important to mention that the experimental procedure was carried out taking into account the environmental conditions.