Dynamic Response of Overhead Transmission Lines to Oscillation Caused by Wind or Rainfall Loads

Abstract

According to the actual state of damaged overhead transmission lines (OTLs) caused by wind/rain loads,a three-tower and two-span finite element analysis model is built,in which the transmission towers are modeled as three degree of freedom (DOF) elements and the conductor/ground wire are modeled as cable elements. The calculation approach of rain load as well as the load combination principle of OTL sustaining combined action of rain load and wind turbulence are proposed; the structural dynamic characteristics of towers,conductor/ground wire and structural system as well as the interrelation among them are analyzed; by means of numerical simulation,different working condition combinations of the design with disaster loads are established and the dynamic response regularity of transmission tower is analyzed in time-domain. Research results show that the influence of OTLs’ motion coupling on structural dynamic characteristics should not be ignored; the rainfall influences on the response of OTL is evident and the former possesses the excitation feature of simultaneous action with wind turbulence; the toppling of towers one after another occurred in structural system is determined by the combined action of wind and rainfall that leads to structural partial instability of dynamic compression.