Performance of Contaminated Insulators Tested from 200 Kv to 1000 Kv DC

The performance of insulators as determined by artificial tests for various contaminant levels at voltage levels ranging from 200 to 1000 kV dc are presented along with comparisons to field measurements. Included are the effects of polarity, insulator shed design, insulator spacing, and uniform and non-uniform contaminant distribution on individual units. The question of linearity of performance with voltage is examined as well as the performance of clean insulators in conditions of fog and heavy rain. Methods of evaluating the ESDD of insulators are also explored.