Application of long tonnage composite insulators on UHVDC V-type strings

In UHVDC transmission projects, long tonnage composite insulators with mechanical strength of 300kN and above will be widely used for V-type strings. Research on operating mechanical characteristics of long tonnage composite insulators is the basis for properly insulator selecting. In this paper, finite element model of overhead transmission line as well as mechanical model for V-type composite insulator verified by load test was constructed. In view of the application of composite insulator FXBZ-800/550 on UHVDC V-type strings, the dynamic tensile and compressive loads under the dynamic operating conditions such as ice shedding, wind swaying and conductor galloping were studied through numeric simulation, so were the influences of ice thickness, wind velocity and galloping amplitude to the insulator loads, and furthermore, the amplification ratio of dynamic peak loads relative to their corresponding static loads was obtained. This research results can provide theoretical references for developing long tonnage composite insulator dynamic load reliability test and selecting its safe coefficient.