and, therefore, in the case of transient analysis, a
variable function of time.
The own resistance of the earthling network,
considered to be constant in the time in previous
papers, is computed, in the present model, through the
use of an algorithm, which is based upon the
“Korsunchev similarity approach” [6], [7].
The analysis of the equivalent lumped-constants
network, through which the protection system is
simulated, is effected through the use of SPICE. In this
analysis each branch of the system is divided in a
suitable number of elements, in order to take into
account the propagation phenomena. The distributions
of the currents due to the stroke upon a point of the
structure are put into evidence and subjected to
analysis. Finally the influence of the ground resistivity
upon said distributions is examined.