Transmission line grounding arrangement that overcomes the effective length issue

Obtaining a low value for the transmission line grounding impedance is an important issue when dealing with backflashover performance. Usually, for high resistivity soils, increasing the grounding grid dimensions does not lead to low impedance due to the effective length issue. In this work, a special arrangement of ground electrodes is proposed in order to overcome the effective length problem in high resistivity soil. The transient voltage response of this low impedance ground arrangement is determined numerically using parametric modeling approach. Additionally, comparisons of numerical simulations results and measurements from a reduced model study are presented for validation purpose. Regarding the calculation, the grounding arrangement behavior is analyzed considering the frequency dependence of ground electrical parameters.