大型变电站接地网的优化设计

为使地表面的电位均匀分布,在不等电位模型的基础上,建立最大和最小接触电压差值最小的目标函数,使用变度量法用数值计算分析得到了均匀土壤时最优压缩比的计算公式。据此可安全、经济地设计不同面积的接地网,确定合理的导体根数,使其散流电流更均匀,并显著减少接地网的最大接地触电压。

Optimization Design of Grounding Grid of Large Substation

To equalize the potential on the earth surface, and to ensure the safety of equipment and people, the calculation formula of the optimum compression ratio is analyzed numerically and obtained in uniform soil, which is based on inequipotential model, and it is obtained when the difference of maximum and minimum step voltage reaches a minimum and by the variable metric method. The results can be used to design different area grounding grids, and determine the rational numbers of grounding conductors, which can equalize the leakage current density and decrease step voltage on the earth surface markedly. Therefore, the designers can design the grounding systems for substations and power plants safely economically.