FDTD analysis of transient potential rise on the steel structure under direct lightning stroke

High transient potential rise could appear everywhere on the LPS when suffering direct lightning stroke, which could cause serious damages to people and equipment in the structure. In this paper, FDTD method is adopted to simulate the discharge process of lightning current in two different situations: stroke on the roof corner and stroke on the roof center. Subsequently, the waveform and the distribution feature of the potential rise on the steel structure are obtained. Furthermore, the influences of the change of the structure on the potential distribution are analyzed. The results show that densified grid on the roof can make the potential distribution on each floor more even which could reduce damages caused by lightning back flashover.