The influence of ground potential and electric field based on relative position in three layers soil

Abstract

The development of high-voltage direct current (HVDC) engineering worldwide has led to an increase in concern over ground potential and electric field pollution, making it crucial to choose a site for direct current (DC) grounding electrode carefully. Soil-layered structure and distance to grounding electrode are the two most crucial factors to consider. While the soil-layered structure throughout the wide area is most likely consistent, it is the distance that proves to be most effective method for improving the reasonable distribution of ground potential and electric field. Although the previous study found that the ground potential and electric field values are greater when the distance to the grounding electrode is shorter, this cannot be applied to a real project. By proposing the analysis approach of equivalent interfacial charge accumulating, we can extract the concept of relative position from the mono-distance ago and conduct a more comprehensive study of their distribution characteristics, surpassing the previous conclusion. According to the research findings, the ideal distribution can be accomplished by shifting the relative position, and as a result, a specific mathematic formula for determining the best relative position has been obtained. Moreover, it should be noted that soil-resistivity and soil-thickness have an impact on computational complexity. The study results were compared and verified using the CDEGS software for a practical HVDC project in China. In the real-world application of the WEICHENG grounding electrode project, we selected the site of the grounding electrode using the approach of relative position with the MOPSO method. The findings suggest that the preferred position for the grounding electrode is between 13 km and 24 km.