Analysis On The Characteristics Of Iced Conductor Galloping Of 1000kV UHV AC Transmission Line

The galloping of iced conductor is a low frequency and large amplitude self-excited vibration generated by the non-circular cross-section of the transmission line drived by the large wind speed. Occurrence of galloping will result in the destruction of the transmission line hardware, line transposition and even rupture, which would cause a wide range of power cut and brought huge economic losses. China’s UHV AC transmission technology is in the first class of the world. According to the national energy development strategy, our country will vigorously develop the UHV technology. The transmission line of each phase is in the form of a split conductor. Although there are a lot of researches on the galloping of iced conductor in China, there are still some problems about divided conductors galloping.The aerodynamic instability of the iced conductor is the direct cause of the conductor galloping. Therefore, the research on the dynamic characteristics of the iced conductor is the main research object of this paper. At present, the most popular and reliable method for the study of the aerodynamic characteristics of iced conductor is wind tunnel test. In this paper, the aerodynamic characteristics of the iced conductor are studied by numerical simulation method, and the feasibility and correctness of the method are verified by comparing with the wind tunnel test results. A two-dimensional and numerical simulation model of the aerodynamic characteristics of iced conductor is established based on ADINA finite element analysis software in this paper. With constant modifying of the model, changing the parameters, adjusting the meshing and selecting reasonable time step, the simulation results of aerodynamic coefficients of the iced single wire and the eight-bundle conductors are obtained. The correctness of the model is verified by comparing with the wind tunnel test results. According to the simulation results, the wake has a huge impact on the three-component coefficients, the drag coefficient suffered the greatest impact.In this paper, the influence of wind speed and ice thickness on the aerodynamic characteristics of the eight-bundle Conductors is analyzed. The three-component coefficients of bundle conductors have a little change with the variation of the wind speed, which proved that wind speed almost has no influence on the aerodynamic coefficients of the conductors. When we change the icing thickness of the conductor, the amplitude of the output curve of the three-component coefficients of the iced conductor increases with the increase of ice thickness, the lift coefficient and torque coefficient curve’s negative slope gets smaller. The greater the thickness of the ice, the drag coefficient of the conductor in the leeward side is obviously lower with the impact of the wake flow of the conductor in the upwind side. Therefore, we prove that the bundle conductor are more prone to gallop, and a large area of ice covered conductor is more prone to gallop.The results of this paper provide a reference for the analysis of the galloping of iced conductor, and provide a favorable support for the improvement of the wind tunnel test model and the parameters setting and optimization.