垂直分层土壤模型下输电杆塔接地电阻的拟合算法

当前垂直分层土壤电性模型下输电线路杆塔接地电阻的精确计算方法过于复杂,不易为普通工程技术人员掌握.基于格林函数的精确算法,对垂直双层土壤电性模型下的典型输电杆塔接地装置的接地电阻值进行了求解.采用最小二乘曲线拟合方法,研究并选取双曲线函数作为拟合函数,对分层土壤电阻率及接地电阻值进行拟合,从而推导出拟合函数表达式,最终得到分层土壤模型下杆塔接地电阻拟合计算公式.对该算法的精度进行了分析,认为其精度与算法中的初值计算有关,但最大误差不超过10%.

Fitting Algorithm for Power Tower Grounding Resistance with Vertical Layered Soil Model

For calculating the tower grounding resistance of power line in vertical layered soil, the accurate al- gorithm is complicated, and is difficult for normal technical staff to grasp. Based on Green function, the re- sistance of typical tower grounding device is calculated. Therefore, the fitting function, which represents the relationship between resistivity of vertical layered soil and resistance values of grounding device, is deduced with the hyperbolic function as a fitting function and by using the least squares curve fitting method. Finally, the fitting formula of tower grounding resistance with the vertical layered soil model is acquired. According to the precision analysis, it is found that the accuracy of the proposed formula is related with the initial value; but its maximum error does not exceed 10%.