In this paper, we investigate validity of RLC equivalent circuit for transient analysis of grounding horizontal electrodes buried in horizontally two-layered soils. The simulation results show that such an equivalent circuit is violated at high frequencies created by lightning strokes. Hence, in this paper, a new equivalent circuit is proposed. In the new circuit model, vector fitting method (VF) is combined with finite element method (FEM) so that a wide-band equivalent circuit is obtained. Such a model is useful for lightning performance of power systems.
