UHV AC Y-type insulator string pollution withstand voltage characteristics

Insulator string is an important part of UHV AC transmission line, and plays an important role in electrical insulation and mechanical support. The new type of insulator string can realize optimization of wire suspension modes and insulator string performance by changing the string structure, which is of great practical value for special transmission corridors with excessively high costs of cleaning. In this paper, voltage-endurance test and electric field simulation calculation are conducted against a new type of UHV Y-type insulator string, and new type of Y-type insulator string structure which is applicable to China's UHV AC transmission line and insulation design are recommended. Test results indicate that, firstly relationship between U50% and salt deposition density is nonlinear and negative exponential decreasing with SDD set as 0.1mg/cm 2 ,0.15mg/cm 2 ,0.25mg/cm 2 and NSDD as 1.0mg/cm 2 . Secondly, U50% of Y-type insulator string is 20.1% lower than that of I-type insulator string, and parameter A is 95.3, α is 0.11. The results of this paper can be used for string design of new type of UHV Y-type insulator string to improve the insulation properties of insulator string, and realize gradual application and popularization of new insulator string in the follow-up UHV engineering.