Effect of Grounding System on Electromagnetic Fields Around Building Struck by Lightning

In this paper, based on the moment method and the circuit theory, an approach is proposed to analyze the current distribution and the electromagnetic field of a building struck by lightning. By introducing the concept of complex resistivity in the air and the soil, the approach can consider the metallic grids under the ground and above the ground altogether. Both the potential differences among the grounding parts and the electromagnetic interactions among the grids are taken into account. It shows that the resistivity of soil will affect the electromagnetic field greatly. When the electromagnetic fields around buildings near the lightning struck point are investigated, or when a building has a separated grounding system, the effect of the grounding systems must be considered.