The scientific research project of " key technology of factory composite insulator and extra-high voltage engineering application " which completed by Nanjing Electric (Group) co., LTD. together with State Grid JiBei Electric Power Scientific Research Academy and Hebei Silicon Valley Chemical co., LTD., has recently won the first prize for scientific and technological progress of State Grid JiBei Electric Power co., LTD.

Since 2015, Nanjing Electric has carried out the study for the related technology of factory composite insulator, doing a lot of experimental researches on RTV coatings and coating layer thickness and different coating ways of different manufacturers. Some of research achievements have been applied to the glass insulators coated with RTV coatings on five extra-high voltage direct current electric transmission line projects of state grid : "Lingzhou - Shaoxing", "Jinbei - Nanjing", "Jiuquan - Hunan", "Shanghai temple - Shandong" and "Changji - Guquan".

This scientific research project is a systematic and normative group experimental study on the research results obtained by various units in the previous state grid project, the experiment verified that avoiding the continuity of glass insulator coating, increasing the area of uncoated area appropriately and ensuring the reasonable correspondence of uncoated area on upper and lower surfaces, so as to improve the shedding rate of self-exploding glass components. (Zi Mu)