Aeolian vibration analysis of transmission lines with spacers

In this paper, aeolian vibrations of power transmission lines are studied and effects of spacers are considered. Each of the conductors is modeled as an EulerBernoulli beam and the spacer is placed as a spring and damper between them. The stiffness and damping coefficient of the spacer has been obtained using experimental tests for a spacer used in Iran's transmission lines. The equations of motion are derived using Hamilton's principle. These equations have been converted into ordinary differential equations using the Gelkerkin method and then numerically solved using the Rang-Kutta method. The effect of using the spacer on the transmission lines and the effect of different design parameters, such as the amount of mass, the stiffness and damping coefficient of the spacer, and the location of the spacer on the amplitude of the vibrations of the conductors have been studied. The results of the simulation have illustrated that the existence of the spacer is necessary to maintain the safety of the lines. However, despite our expectations, not only does a hard and heavy spacer have minimal impact on the control of vibrations but also can have adverse effects. It was also shown that increasing the mass of the spacer up to 10 times reduces the range of vibrations by 11% and the minimum stiffness equal to 2×106 (N⁄m) is needed for the spacer. Because in this value, the amplitude of vibrations decreases up to 2 times compared to lower stiffnesses.