A Concise Approach of Soil Models for Time-Domain Analysis

• Published in: IEEE transactions on electromagnetic compatibility Vol. 62; no. 5; pp. 1772 - 1779
• Main Authors: Salvador, Joao Pedro Lopes, Alipio, Rafael, Lima, Antonio C. S., Correia de Barros, Maria Teresa
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-10-2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analytical models; Approximation; Bonding and grounding; Conductivity; Frequency domain analysis; Mathematical model; Mathematical models; numerical methods and modeling; Parameters; Permittivity; Poles; Soil; Soil analysis; soil parameters; Soils; Time domain analysis
• ISSN: 0018-9375; 1558-187X
• DOI: 10.1109/TEMC.2019.2927273

This paper proposes to represent the frequency dependence of soil parameters via a rational approximation in the frequency domain. Two types of causal soil models were considered, namely, Smith-Longmire and Alipio-Visacro (AV). Results indicated that for both soil models, the analyzed parameters maintain a fixed ratio between the poles and residues, and for the AV soil model, there is a unique set of poles, representing a "universal" set of relaxation frequencies. Thus, without resorting to an additional fitting process, one can find a suitable rational approximation of a frequency-dependent soil for an arbitrary conductivity, which is very useful for its inclusion in computational codes in time or frequency domains.