DC contamination performance of station insulators

The authors describe the results of an investigation of the contamination performance of equipment insulators under the application of a DC voltage. Artificial contamination tests on insulators with various shed profiles were carried out. In addition to total leakage distance, shed profile is found to play a role in determining the DC withstand voltage. Deep-rib-type insulators exhibit a superior DC contamination performance compared to other types of insulators. Anticontamination design criteria that are based on the results of the investigation are given for DC equipment insulators.<>