Influence of desert pollution on the lightning impulse breakdown voltages of rod to plane air gaps

A discussion is presented of the influence of desert contamination on the breakdown voltage characteristics of rod-plane air gaps when subjected to standard lightning impulse voltages of positive and negative polarities. Experimental simulation of desert air pollution was carried out in a chamber where particle parameters could be controlled independently. The gaps studied were from 5 cm up to 2 m with applied voltages, there is a considerable influence on the breakdown behavior. For such cases, the breakdown voltages for dust contaminated gaps can be lower as well as higher than the corresponding values for clean air gaps, depending upon the gap length and the cathode radius. Detailed results and analysis are provided