On the Transmission-Line Approach for the Evaluation of LEMP Coupling to Multiconductor Lines

This paper provides some clarification on the subject of the response of multiconductor lines to lightning-originated electromagnetic fields. Specifically, the effect of the presence of more conductors on the line response is analyzed with and without taking into account the ground losses in the surge propagation. The effect of the boundary conditions is also discussed. The presented analysis shows, in particular, that the response of a matched multiconductor lossless line differs from that of a single-conductor line at the same height only in the line currents. The effect of the nearby line conductors on the induced voltages is, indeed, noticeable when the ground losses are taken into account in the surge propagation.