Calculation of Overhead Transmission Line Impedances A Finite Element Approach

In this paper, the finite element method (FEM) is used to calculate the frequency dependent series impedance matrix of an overhead transmission line. A novel approach is proposed, leading from FEM results to the direct computation of the symmetrical components impedance matrix of any single or double circuit transmission line. Results show excellent agreement with those obtained by classical computation methods. Test cases examined include impedance calculations in the presence of certain terrain irregularities in the line neighborhood, such as line by a mountain side of variable slope, line inside a canyon or line near a water region.