计算土壤参数的一种新方法

New Method of Computing Soil Parameters

确认大地模型和土壤参数是变电站接地网模拟计算的首要工作。通过电磁场理论和格林函数 ,利用递推算法获得水平多层土壤中电流场的地电位分布 ,结合复镜像法 ,推导出四极法所测视在电阻率与极间距的关系。引入非线性目标函数 ,将土壤参数问题转化为求目标函数的极值问题 ,采用拟牛顿的最优化方法 ,可快速求出土壤的参数。用该方法编制的软件可准确地确定任意层土壤模型。

The determination of earth structure and soil parameters is essential in the simulation of substation grounding grids. By electromagnetic field theory, Green function and using recursive algorithm, the potential distribution of the earth due to point current source in horizontally stratified multi-layer earth is presented, combining complex image method, the relationship between the apparent soil resistivity measured by the Wenner four poles method and the measurement pole span is also obtained. A nonlinear target function is introduced to transform the problem from the analysis of structural parameters to calculating the limited value of the nonlinear target function, combining Quasi-Newton optimization method, the parameters of soil are easily and quickly obtained. The software established by the method can accurately determine the parameters of layered soil.