Analysis of Grounding Performance of Tower Grounding Electrodes in Elevated Terrain

Tower grounding electrodes are closely related to lightning protection performance and the safety of transmission lines. Therefore, an accurate evaluation of the grounding performance of tower grounding electrodes is significant. However, existing methods (method of moments) for calculating grounding parameters of tower grounding electrodes and the measurement method (3-probe method) of the grounding parameters hardly considered the influence of the elevated terrain and mainly regarded the earth as the horizontally half-space (uniform or layered) soil. Those existing methods could cause large errors in grounding designs and measurements in elevated terrain, which could further result in potential electrical accidents. To solve the above problems, this paper studies the grounding performance of grounding electrodes in elevated terrain. Firstly, the calculation method for grounding parameters in elevated terrain is proposed. Secondly, the influence of elevated terrain on true grounding resistance (GR) and measured GR by the 3-probe method is analyzed. Finally, the suggestions for the grounding design and 3-probe method in elevated terrain are given. This paper can provide a theoretical basis for the design and measurement of tower grounding electrodes in elevated terrain and help obtain accurate grounding parameters in elevated terrain, which is of great significance.