Modelling of Aeolian Vibrations of Bundled Conductors

Reliable transmission line design requires that vibration of the conductors due to wind is controlled below critical levels to avoid fatigue damage. Newly designed lines, lines that are being modified to carry higher current voltage and lines that are being assessed for life extension, all require vibration control for safe levels. Approaches available to guide this assessment process can be pragmatic, through design rules based on the past experience. Also, conditions can be assessed through measurement on existing lines, using special purpose measuring instruments. This chapter deals with an analytical approach which may be used to investigate alternatives in the design or redesign process. In particular, this chapter describes the energy balance principle (EBP) which is used to estimate an upper bound to the expected vibratory motions, gives examples of measured wind and conductor data used, and some comparisons with available field measurements.