Lightning transient voltages in cables of a large industrial site using a FDTD thin wire model

The thin wire formalism of Holland-Simpson is used to model the different structures of a large industrial site in a FDTD volume. Extensions performed to the original formalism allow to shift the wire along the FDTD cell, to trace oblique trajectories, to model bare wires, insulated, and coaxial cables. The different types of thin wires are used to model: the lightning channel, the building, the grounding grid, a control cable and a cable route. Currents are computed along the shield and core of the control cable, and voltages are observed in its terminations. The results were compared with a MoM numerical tool, with good agreement and a significant better performance in terms of computational resources. Considerations on the modeling of two types of cable routes are addressed: a dielectric pipeline and a cable duct. Finally a simplified approach to compute the transient voltages in the ends of a coaxial cable is presented.