The Research on the Impulse Characteristics of the Extended Grounding Electrode in the Layered Soil

The composition of the tower's grounding system is always with several layers, for single-layer structure of the tower in high soil resistivity area, it is the use of partial replacement of soil to reduce the tower grounding resistance, also the analysis object is equivalent to the hierarchical model, Therefore, the study of layered soil structure tower grounding impulse characteristics is more representative. To study the impact properties of the layered structure of the soil grounding, In this paper, through the establishment a double-layer soil model structure, the impulse characteristics of the soil structure of grounding electrode is studied through simulation, resulting of the quantitative relationship between several high resistivity soils partially replacing low resistivity soil area size and impulse grounding resistance of elongation grounding. The results show that the impulse grounding resistance decreases as the replacement area of low resistivity soil increases and converges to a certain value, which indicates the impulse characteristics of extended grounding electrode in double-layer soil model increases with the expand of the upper level low resistivity zone and approaching that of single layer with low resistivity soil. The results have a reference value for use of local soil replacement method to reduce tower impulse grounding resistance in high soil resistivity areas and the determination of soil replacement plan.