Finite-Difference Time-Domain Study on the Influence of the Conductor Catenary in the Simulation of Lightning Surges

When accounting for the catenary shape, overhead power lines are non-uniform structures. Usually, the impact caused by the catenary on the transmission properties of the line is neglected. Hence, the line is simulated as uniform considering a constant equivalent height. In this paper, we investigate the impact of the catenary on induced overvoltages caused by direct and indirect lightning strokes. Employing a recently proposed implicit finite-difference time-domain code, we assess that the catenary may have a severe impact on the correct computation of the overvoltages. Finally, we outline the accuracy limits of the EMTP-RV software in conjunction with the LIOV module through an in-depth comparison.