Corona ring optimization for V-insulator string on the point of RIV and AC flashover performance

This paper presents corona ring optimization of V-insulator string with respect to field simulations, RIV levels and AC flashover voltages. Corona ring diameter, tube diameter and installation height are considered as optimization parameters. Variations of electrical fields on the critical parts of the string are obtained by 3D simulation studies for different ring settings and optimum parameters are determined. Later, the concordance between laboratory RIV test results and calculated field values are investigated. AC flashover tests are also performed to validate the AC isolation level of the system under different ring settings.