A Novel Estimation Strategy for Electrical Parameters of Multi‐Layer Soil in Frequency Domain

Frequency‐domain soil parameters have an important influence on the response of earthing systems subject to impulse current. To estimate the frequency domain parameters of horizontal multi‐layered soil effectively and quickly, a novel estimation strategy based on a nonhomogeneous cuckoo search algorithm (NoCuSa) is proposed. Firstly, NoCuSa is applied for estimating the electrical parameters of multi‐layered soils, with their performance verified by the software CDEGS (Current Distribution, Electromagnetic Fields, Grounding, and Soil Structure Analysis) in the DC case. Then, Messier expressions combined with the discrete complex image method (DCIM) are utilized to generate the synthetic soil complex apparent resistivity. On the premise that the variation of optimal depth per layer is insensitive to the change of frequency, this paper defines only the conductivity and permittivity of each layer as variables to be optimized when the frequency changes. Therefore, the runtime of each frequency point could be reduced compared to the common way; the effectiveness of the proposed estimation strategy is verified by experimental and simulation examples. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.