Simulation of grounding system in soil with frequency-dependent specific conductivity

Specific conductivity of soil depends on frequency that must be taken into account in calculations of
impulse processes in grounding systems under lightning current. The Fourier method currently does not
require modification of the standard model of the grounding system, but the scope of its applications is
limited by linear problems, and difficulties with the causality principle may arise. We have developed a timediscrete
model of a grounding system in soil with arbitrary frequency-dependent complex specific
conductivity, suitable for calculations of impulse transient processes using standard methods in time
domain. It is shown on numerical examples that overvoltage impulses in grounding systems, which are
located in high-resistance soil with frequency-dependent parameters, are significantly smoothed and
attenuated under the influence of current impulses with short front and short duration.