The finite element of modelling of the dynamic behaviour of a transmission line conductor

Abstract

The problem of conductor motion has been of concern to transrruss1on line engineers for many years. This thesis describes the application of one of the most powerful and useful tools of modern engineering, the finite element method, to the problem of modelling the dynamic behaviour of conductors. In modelling the conductor, the assumption that it may be treated as a solid continuum is made. Due to the construction of a conductor, however, the bending stiffness and internal damping of the conductor are non-linearly related to a number of factors. The results of a study on these factors are discussed in this thesis, and have been used where necessary in defining the material behaviour of a conductor. Four types of conductor motion are modelled, namely aeolian vibration, wake-induced vibration, bundle pinch (resulting from short-circuit currents) and the motion of a section of a transmission line after a conductor breaks. Finite element models have been developed specifically for each of these types of conductor motion, and the details of these are presented. The effects of various options in the finite element modelling, on the results obtained from the simulations, are also discussed. The finite element models are implemented by means of the finite element package, ABAQUS. Algorithms which have been developed and implemented by means of user-defined subroutines for the simulation of vortex shedding loads (in the case of aeolian vibration), electromagnetic forces (due to short circuit currents) and the loads experienced by a conductor in the wake of another, are discussed in the thesis.