Use of the full-wave finite element method for the numerical electromagnetic analysis of LEMP and its coupling with overhead lines

The computation of lightning-originated surges on overhead power lines due to nearby lightning return strokes requires accurate models for the calculation of both the incident lightning electromagnetic pulse (LEMP) and the coupling of this field with the line conductors. The availability of numerical algorithms for the resolution of full-wave Maxwell´s equations (also called numerical electromagnetic analysis - NEA) could provide benchmark results useful to assess the uncertainties introduced by approximate models and solution methods. Within this context, the paper presents and discusses the results of LEMP and lightning-induced voltages calculations obtained using a time-domain full-wave Finite Element Method (FEM) model. The results obtained by the FEM model are then compared with those provided by traditional approaches based, for the LEMP calculation, on the combined use of the dipole technique and the Cooray-Rubinstein formula and, for the LEMP-to-line coupling, on the Agrawal et al. model.