Loss transmission-line model of grounding electrodes considering soil ionization of lightning impulse

A loss transmission-line model with distributed time-variable parameter for the calculation of transient characteristic of a grounding system under lightning to consider the dynamic and nonlinear effect of soil ionization around the ground electrode is proposed. The influences of the length of grounding electrodes and location of feed point on the transient characteristic of ground electrodes are analyzed. Grounding electrodes have impulse effective length under impulse current. The model has been validated by comparing the numerical results with experimental tests.