Time-Domain PEEC Transient Analysis for a Wire Structure Above the Perfectly Conducting Ground With the Incident Field From a Distant Lightning Channel

This paper presents the time-domain partial element equivalent circuit (PEEC) analysis of induced transients in a wire structure during an indirect lightning strike. The full-wave PEEC formulation with an external incident field is employed. The incident field is calculated with either the Uman's or the Jefimenko's formula by using the engineering model of a lightning channel. An instability problem is, however, observed. It becomes a hurdle in the application of PEEC for evaluating induced transient currents in closed wire loops. The problem is investigated, and is primarily caused by discretization of the electric field in numerical evaluation of external voltage sources. An algorithm is provided to solve this instability problem, and is tested for both near- and far-field cases. It is validated by the finite-difference time-domain method. The issue of time step and segment length is addressed. It is also found that the Uman's formula is generally incapable of producing stable induced currents in a wire loop structure. Finally, the proposed PEEC procedure is applied to evaluate induced lightning transients in a photovoltaic panel during an indirect lightning strike.