Analysis Of Characteristics And Parameters Of Anti-Galloping Device Based On Two-Degree-of-Freedom Forced Vibration

Transmission line galloping is a kind of low-frequency,large-scale vibration generated by asymmetric cross-section wires under the action of wind load.The galloping will cause damage to wires,tower bolts,fittings,etc.In severe cases,the tower will collapse.All the above will pose a serious threat to the safe operation of the transmission line.Therefore,the installation of anti-galloping devices on the transmission line has been widely used in the prevention and control of transmission line galloping as a simple and effective anti-galloping measure.Based on the two-degree-of-freedom forced vibration mechanism,an anti-dance device was designed and the parameter research was conducted,which has certain significance for the anti-galloping research of transmission lines.In this paper,one of the anti-galloping devices torsion suppression ring is took as the research object.Based on the principle of spring vibration absorption,the two-degree-of-freedom forced vibration system is used to design the anti-galloping device to improve the anti-galloping performance of the torsion suppression ring when the line is galloping.Firstly,the design of the torsion suppression ring device is improved,the structure diagram,basic dimension diagram and 3D diagram of the improved torsion suppression ring are given.Secondly,the single degree of freedom model and the two degree of freedom model of the torsion suppression ring are established respectively.The anti-galloping effectiveness of the improved torsion ring is proved.Then the modal analysis of the improved torsion suppression ring is carried out by using the finite element software.The mode shape of the device is determined and the influence of the stiffness of the vibration-absorbing spring and the torsion spring on the natural frequency of the device in the vertical direction and the torsional direction is studied.Finally,a simplified finite element model of the torsion suppression ring-transmission line conductor system is established,and the galloping excitation is applied.The vertical galloping displacement,the galloping axial force and the galloping frequency at midspan of the transmission line before and after the installation of the improved device are analyzed under four different arrangements.The results show that the improved torsion suppression ring can reduce the peak-to-peak and maximum values of the vertical galloping displacement,the peak-to-peak and maximum values of the galloping axial force,and the frequency of the galloping at the midspan of the transmission line compared of the original torsion suppression ring.When the improved torsion suppression ring is arranged at five points with unequal pitches,the anti-galloping effect is optimal.