Application of the System Identification Method to Model the Transient Response of Grounding Plates

Ground potential rise (GPR) is a crucial factor in the measurement of lightning protection. To quantitatively analyze the GPR when lightning hits the transmission lines or buildings, we need a mathematical model that describes the grounding system. This paper proposes a modeling method for grounding systems based on the curve fitting and system identification methods. We used a 600 mm x 600 mm grounding plate to verify the validity of the proposed modeling method. The valid soil resistivity of the result model created by proposed method ranges from 0.1 Ωm to 2000 Ωm, and the maximum frequency of the adaptable input signal is 8 MHz. The resulting transfer function model can be taken as an electrical component to link with other circuits in most of commercial circuit simulation software.