Study on Icing Performance of 110kV Insulator Strings at AC Service Voltage

Insulators’ icing is one of the severe problems for external insulation of transmission lines and there are a lot of reports about power outages caused by flashover of the ice-covered insulators from all over the world. Therefore, it is very significant to investigate the icing process and the icing performances of insulators. Experiment investigations are carried out on 110kV composite insulators and 7 units of IEC standard suspension porcelain insulator string as well as 7 units of XWP-160 anti-pollution porcelain insulator string energized with 64kV voltages in the artificial climate chamber of Chongqing University. Based on the test results, it puts forward that there are evidence difference in ice status between the energized insulator strings and the non-energized ones. The energized insulators at the high voltage end are hard to be bridged by icicles and the ice density accreted on energized insulator string is lower than that of non-energized ones. It also shows that the electric strength, the material, type, structure of insulators and the water conductivity may influence the ice density.