On the computation of damped wind-excited vibrations of overhead transmission lines

Vibration of elevator cables with small bending stiffness

A novel algorithm is developed in this paper for analyzing Aeolian vibration of a span of a single conductor with multiple dampers. The algorithm is characterized by a combination of an impedance transfer technique (ITT) and a forced vibration method (FVM). The ITT avoids singularities that may occur due to a conductor's very low bending stiffness with respect to its tension. On the other hand, the FVM can easily handle non-proportional damping (which is typical for the problem in concern) without having to solve a complex eigenvalue problem. In addition, the algorithm can easily accommodate a conductor's terminal flexibility as well as a damper's rotational effect that may exist due to its possible asymmetry. The algorithm is very efficient so that solution is almost instantaneous for most analysis problems. The algorithm has recently been implemented into a commercial Aeolian vibration analysis and design software-EPRI Vibration version 3.0.

An Efficient Algorithm for Aeolian Vibration of Single Conductor With Multiple Dampers

This paper reports a systematic investigation on the linear and nonlinear dynamics of a suspended cable, taking bending stiffness into account. Firstly, the linear dynamics features, for example, e...

Linear and nonlinear dynamics of suspended cable considering bending stiffness

Various numerical tools have been developed to predict the level of aeolian vibrations for a damped span of transmission-line conductors. In part I of this study, nonlinear time history models of two types of transmission-line dampers were developed. In this paper, a model for the complete conductor-damper system is presented. When combined with empirical equations for wind power input and conductor self-damping using the Energy Balance Principle, the direct integration time history model proposed allows the prediction of the vibration amplitudes expected on a damped span. The amplitudes predicted by the model compare well to experimental data sets available in the literature. Since the damper is modelled from its mechanical properties of geometry, mass, stiffness, and damping, the optimization of a conductor-damper system can be done easily with this model, without additional experimental tests. A sensitivity analysis is conducted to demonstrate the capabilities of the model.

N. Ganesan

Papers

Transmission line vibration with 4r dampers