Experimental Research on Temperature Rise Characteristics of High-Voltage Disconnector Electrical Contacts Based on Ag-Graphene Composite Coatings

In order to solve the overheating problem of high-voltage disconnector electrical contacts caused by the wear and dirt during the long-term operation, and thereby improve the safety and stability performance of the power grid, there is an urgent need to research and propose new high-performance electrical contact materials. In this paper, electrical contacts based on Ag-graphene composite coatings were prepared by a cyanide-free process, and a temperature rise experimental platform was built based on a GW4-40.5 type disconnector. And then, the influence of current, surface contamination, surface wear, and wear plus contamination on the temperature rise characteristics of disconnector contacts is studied. The results show that the modification of Ag-graphene composite coatings can improve the temperature rise characteristics of the disconnector contact, and has good pollution resistance and wear resistance. Among them, the contact based on hard Ag-graphene composite coatings shows the optimal temperature rise characteristics when worn and polluted. The introduction of graphene is helpful to solve the problem of abnormal heating caused by the electrical contacts of disconnectors during long-term operation, and has broad application prospects.