雷电防护深井法降阻效果分析

Effect Analysis of Resistance Reduction Using Deep-Well Method

通过对钢管作垂直接地极接地电阻的理论计算和工程实践,分析了深井法降阻与土壤电阻率、接地极深度及接地极直径的关系。研究表明:深度越深,降阻效果越差;土壤电阻率越大,降阻效果越好;直径越大,降阻效果越差。从接地极电流密度、接地极放电的端部效应等因子的影响对深井法降阻效果的特点进行了定性的解释。同时考虑到雷电流的大地趋肤效应,从建设成本考虑,提出不宜在土壤电阻率较低的地区推广深井法,且接地极直径达到一定大小后,再增加直径的降阻效果已不明显,性价比不高,故接地极的直径也不宜太大。

Based on theoretical calculations and engineering practice for the grounding resistance of the vertical grounding electrode using a steel pipe, an analysis is made of the relationship between the effect of the resistance reduction using the deep well method and soil resistivity, as well as the depth and diameter of the ground electrode. Its characteristics include： the deeper the depth, the worse the effect of reduced resistance; the bigger the soil resistivity, the better the effect of resistance reduction; the bigger the diameter, the worse the effect of reduced resistance. The characteristics of the effect of the resistance reduction using the deep well method are explained qualitatively from the influence of the grounding electrode current density and discharge end effect. Simultaneously, considering the earth skin effect of lightning current and the construction cost, it is concluded that the deep well method is not recommended in the areas with lower soil resistivity; after the grounding electrode diameter size reached a certain size, increasing the diameter of the grounding electrode will have little effect in the resistance reduction, so the diameter of the grounding electrode should not be too big.