In-Plane Nonlinear Vibration of Overhead Power Transmission Conductors With Coupling Effects of Wind and Rain

In this paper a small sag-to-span ratio conductor, belonging to overhead power transmission conductors, is studied. The single conductor is assumed to withstand a prescribed motion at a single conductor ends caused by suspended insulator swing and placed in the simultaneous wind and rain condition. It is modeled as a planar, nonlinear, one-dimensional continuum, and its ends are assumed to undergo the suspended insulator swing of given amplitude and frequency. Raindrops are blowing by uniformed wind flow, hitting the single conductor and may form rivulets on its surface. Besides rain-wind flow induces aerodynamic instability, the motions of the suspended insulator swing contribute to external and parametric excitation. Vertical motion equation of the single conductor is discretized with Galerkin method of which first order in-plane symmetric mode is took as trial function. Multiple-scale perturbation technique and computation methods are introduced to study nonlinear dynamic responses of the single conductor under parametric excitation or force excitation, or both excitations. Effects of key parameters, such as total damping ratio, upper rivulet angle, suspended insulator swing amplitude and frequency on dynamic characteristics of the single conductor are discussed. The results indicated that those key-parameters have obviously affected the dynamic characteristics of high-voltage conductor.