Research On Aerodynamic Characteristics And Galloping Of Iced Quad Bundle Conductor

Galloping of transmission line is a self-excited vibration with low frequency and large amplitude induced by wind load when the cross section of conductor is iced,which cause wear and damages to the conductors,the tower and other components.The rapid development of the scale of power grid and the frequent occurrence of bad weather in recent years,making frequent occurrence of galloping.Seriously affect the safe operation of power grid,resulting in significant economic losses.Therefore,the research on galloping and anti galloping technology of iced transmission line has obvious economic and social value.This paper takes EHV quad bundled transmission line as the object,and carries out the following research.1.The flow field around of the iced quad bundle conductor under the wind load is simulated,and analysis of its aerodynamic characteristics.First establish the numerical model of typical crescent iced quad bundled conductor.Then analyze the influence of the wake effect of sub-conductor on the aerodynamic coefficient.Finally calculate the aerodynamic coefficients of sub-conductors varying with attack angles.2.The galloping of quad bundle conductor is simulated,and analysis the galloping's characteristics of different span line.Establish the finite element model of quad bundle transmission line,and the aerodynamic coefficients of each sub-conductor are converted into the overall aerodynamic coefficients,load on the finite element model of quad bundle transmission line and simulate the whole galloping.Through the simulation,the initial wind angle of galloping is obtained,and the characteristics of galloping of different span transmission lines under initial wind angle are analyzed by the displacement response,trajectory and displacement spectrum.3.The installation schemes of phase-to-ground spacer in different span line,and analysis its effect of anti-galloping.anThe finite element model of phase-to-ground spacer is established,Then determine installation schemes by the characteristic of galloping of different span quad bundle transmission line,and carry out comparative analysis about the line's galloping response before and after the anti-galloping devices' installation according to displacement,trajectory and tention.The result shows that galloping caused great damage for transmission line,at the same time,different installation schemes of phase-to-ground spacer at different span transmission line works well for anti-galloping.The rapid development of national economy and power grid has put forward higher requirements for safe and stable operation of transmission lines.The research on aerodynamic characteristics and galloping of transmission lines is necessary and urgent.The results provide a necessary reference for the aerodynamic characteristics and galloping analysis of EHV quad bundled conductors,and provide great significance for different span EHV transmission line's anti-galloping technology and experiment study on the phase-to-ground spacer.