Influence of Soil Conductivity and Rod-to-Earth Gaps on Lightning Breakdown Voltage and Peak Current of Rod-to-Plane Air Gaps

International audienceThis study deals with the influence of soil conductivity and a rod-to-earth electrode gap on lightning impulse voltages. Two types of soils are considered: homogeneous and non-homogeneous/heterogeneous. The heterogeneous soil consists of a metallic plate in contact with a parallelepiped tank filled with water or wetted sand of different conductivities. It is shown that, for homogeneous Earth, the U50 decreases when 50% increasing the soil conductivity and the electrodes gap decreases. For heterogeneous soil configuration and a given distance from the HV electrode to the metallic electrode, the U50 is higher for lower conductivities of 50% homogeneous soil