Mechanics And Galloping Analysis Of Overhead Transmission Lines

Environment’s variability brings great threat to the safe operation of thetransmission lines. Due to the effect of the wind, transmission lines are in varyingdegrees of vibration. In certain weather, ice conductor can produce low-frequency andlarge amplitude vibrations, that’s galloping.The galloping can induce short-circuit andthe broken of the component,even the broken of the lines and towers.The accidentscause great economic loss.In order to ensure the safe and reliable operation of thepower grid,it is necessary to determine the current operating state of the transmissionlines according to the known information. in order to take timely preventivemeasures,we can analysis the expect accidents.In this paper, the transmission lines are studied from two aspects of mechanicsand vibration, mainly including the static response of transmission lines,gallopinganalysis and aerodynamic simulation.First of all,the static response of the conductor are analysied based on the methodof the direct balance.The static response includes the transmission lines’ configurationand the tension calculation. Application of catenary equation of theconductor,analyzes the four situations with concentrated load and without that,and theiced conductor,and the iced conductor under the static aerodynamic. The analysis ofthe above provides the basis to judge the operation state of the transmission lines andthe analysis of galloping.Secondly,we deduce the nonlinear motion equations of the ice conductor basedon the energy balance method and lagrange equation. Simulate the galloping responseof the conductor;then use the fourth order Runge Kutta method to get the numericalsolution of the galloping response.So that we can get the maximum amplitude ofvibration.Finally,based on the software of Fluent, setting up a thin ice aerodynamiccalculation model of the conductor,and examining the feasibility that numericalsimulation insteads of the wind tunnel test. This paper simulates the aerodynamiccoefficient under the corresponding wind speed. The results show that in this paper,the calculation results and test results is consistent.What’s more,based on thesimulating aerodynamic force coefficient,the configuration of the iced conductorunder the static aerodynamic and the vibration equations are verified.