Galloping Mechanisms And Numerical Simulations Of Iced Conductors

Transmission wires are subjected to their own weights and ice weights, as wellas dynamic loads from the wind. In certain meteorological conditions, steadytransversal wind may cause iced conductors the large amplitude, low frequencyoscillation, namely the dance. Iced conductor galloping occurs frequently, whichposes a serious threat to the safety and reliability of the grid. Because the shape ofthe ice around wires is random, and the reason of the dancing is very complex, sothe research on galloping is very difficult. In a word, the research has importanttheoretical and practical value and has great economic and social significance.Based on the aerodynamic characteristics of conductor galloping, with theproperties of the typical ice shape, and by the principle of fluid dynamics, the fluidfield around iced conductors is analyzed. The crescent shape model of ice aroundconductors is used. The windward format of finite difference is applied fornumerical calculation. The drag coefficients and lift coefficients at various anglesof attack are calculated through numerical simulation. The influence of the windspeed, attack angle on conductor galloping is discussed. Besides, the cableelements are used to simulate iced conductors. Using the ANSYS, the mechanicsmodel of iced conductor galloping is established. The wind-induced dynamicresponse of iced conductors is studied by the modal analysis by using harmonicwave superimposing method. Six natural frequencies and eigenvectors are got andthe displacement response curves of some vibration mode of the line are drawn,which can offer some reference for the design of the iced conductor. Finally, thefurther problems in the research of conductor galloping are put forwards for furtherinvestigation.