Multi-rigid-body model of dynamic wind-induced deflection for overhead transmission lines

Traditional static analysis method cannot calculate the dynamic wind-induced deflection response of overhead lines, and the finite element method(FEM) was complicated model and cost long calculation time. Aiming at the problems, a multi-rigid-body model for calculation of the dynamic wind-induced deflection response of overhead transmission lines under high wind conditions was proposed. Firstly, the insulator string was regarded as a rigid straight rod with uniform mass, and the equivalent rigid rod of conductor was derived based on the principle that the natural frequency of the conductor swings at the mean value of the wind-induced deflection is constant. The aerodynamic damping was calculated according to the relative movement of the incoming wind and the overhead line, and further the multi-rigid-body model of dynamic wind-induced deflection of overhead transmission lines was established by the analytical mechanics method. Secondly, the spatial distribution of the fluctuating wind field was simulated based on the Kaimal spectrum and the Davenport coherence function. On the basis, the variation law of dynamic wind-induced deflection response of the multi-rigid-body model of the overhead lines was obtained from an engineering example. Finally, the modal analysis of the multi-rigid-body model was carried out, and the wind-induced deflection responses obtained by the multi-rigid-body model were compared with those obtained by the traditional static method and FEM, which verified the accuracy and efficiency of the multi-rigid-body model. The results show that the flexibility of conductor has little effect on the wind-induced deflection response of the insulator strings. Moreover, the multi-rigid-body model can calculate the dynamic wind-induced deflection response of the insulator strings accurately and efficiently, which can present the relative position changes of the wind-induced deflection of each insulator string in the overhead transmission lines. Compared with the traditional static analysis method, the multi-rigid body model can calculate the dynamic wind-induced deflection angle of insulator string. Compared with FEM, the multi-rigid-body model costs less calculation time and has higher calculation efficiency. © 2020, Central South University Press. All right reserved.