Evaluation of Ground Potential Rises in a Commercial Building During a Direct Lightning Stroke Using CDEGS

This paper utilizes CDEGS software to calculate the transient ground potential rise (GPR) in a commercial building, with a base of 39m x 13m and a height of 21 m, during direct lightning strokes. The influences of soil resistivity, location of the lightning strike point, and wave shape of the lightning current on the transient GPRs of three scenarios for the building are analyzed. Such scenarios within the building include the following: 1) devices are grounded independently; 2) devices are grounded via vertical ground electrodes that are connected to each down conductor fixed on the outside of the building; and 3) devices are grounded via a ring ground electrode that is sited around the periphery of the building. The results show that the ring ground electrode provides effective lightning protection for the building under lightning and, therefore, is recommended.