Method and Mathematical Model of Suppressing Forced Vibrations in Single Conductors of High-Power Transmission Lines

Abstract

A new method to suppress the galloping of electric conductors in high-power transmission lines based on isochronous roller vibration dampers is proposed. The mathematical model of the dynamic process of suppressing the conductor galloping was constructed, including the interaction effect of the damper and string of insulators as a bearing body. This model differs from the previous ones since it accounts for the string rotation together with the damper due to its deviation from the vertical and special shaping of the damper grooves. The mathematical vibration protection model was devised with two nonlinear differential equations, which, after their linearization and integration, can find the amplitude-frequency response equation in the linear statement of the problem. The formula was analytically derived for the natural vibration frequency of the working body center of mass in the isochronous damper, which does not include the roller radius. The critical control damper parameters, which affect the suppressing quality and efficiency of forced conductor vibrations, are defined. The graph-numerical method was advanced to determine the optimum parameters of the damper adjustment. The damper offers the advantage of its natural frequency independence of the working body amplitude. This property provides high adjustment accuracy of its parameters and best performance over the low-frequency range. The isochronous damper can greatly decrease the conductor galloping level: the angle of the insulator string deviation from the vertical can be reduced fivefold.