An Algorithm for the FDTD Modeling of Flat Electrodes in Grounding Systems

A sub-cell algorithm for the finite-difference time-domain (FDTD) modeling of flat electrode in grounding systems is proposed. The electromagnetic field variation near a flat electrode is derived from the integral of the differential electric field which is radiated by the distributed charge on an electrostatic charged flat electrode. By fully incasing the field singularity into the coarse cells containing the electrode with the Faraday´s Law, a sub-cell algorithm has been proposed to reduce computational resources when modeling the flat electrode. The accuracy of the derived field singularity is verified from comparison with the field given by the high-resolution standard FDTD simulation. The efficiency of the proposed algorithm has been approved by verifying the transient grounding resistance (TGR) of the grounding system using the proposed algorithm and the computational memory and time usage.