Contamination Flashover Performance of DC Insulator Strings

The results of the research on contamination flashover performance of DC insulator strings for ±500 kV HVDC system are presented and the ±600 kV artificial pollution test equipment for DC contamination in China Electric Power Research Institute(CEPRI)is described.After comparing the results of contamination flashover performance of DC insulator strings with those obtained in two labolatories in other countries the linear relation between pollution withstand voltage and the number of insulator units is verified.Artificial pollution tests on contamination flashover performance of long suspension insulator strings under uniform and non-uniform distribution of contamination are carried out respectively and a lot of valuable test data are obtained.