Dynamic Analysis of Power Transmission Lines With Ice-Shedding Using an Efficient Absolute Nodal Coordinate Beam Formulation

Abstract

Dynamic analysis of power transmission lines with ice-shedding is conducted in this work. The power transmission line is first simplified as a uniform slender round beam. While the beam can have large displacements, rotations, and deformations, its strains are assumed to be small. The bending stiffness of the transmission line is considered here, but its shear and torsion effects are neglected. An efficient absolute nodal coordinate beam formulation is developed based on the above assumptions, and the number of generalized coordinates of each element of the beam is reduced to the least. The mass matrix is constant and the generalized elastic force is evaluated by constant stiffness tensors and generalized coordinates; hence, the current formulation is very efficient. Dynamic responses of power transmission lines with ice-shedding are then calculated. A benchmark planar two-span line is first considered, and the results are validated by the commercial finite element software abaqus. By examining strain states of the transmission line, it is found that its bending stiffness cannot be neglected in this dynamic analysis. Dynamic analysis of a three-dimensional three-span line is then conducted, where towers are not in a straight line and elevation differences between adjacent towers are considered. Several cases with common ice detachment mechanisms are considered, and dynamic responses of the cable and reaction forces of insulators due to ice-shedding are analyzed.