广义Sommerfeld积分矩函数方法及其在接地网参数计算中的应用

Moment Functions for Sommerfeld Generalized Integral and Its Application in the Evaluation of the Grounding Grid Parameter

随着接地网面积的不断增大,接地网计算工作量不断增大,水平分层土壤中接地网特性快速计算方法具有重要意义。采用复积分路径的方法实现了水平方向距离大于垂直方向距离情况下格林函数的计算,该方法将贝塞尔函数振荡因子转变成指数函数衰减因子;同时,对于有限区间的高振荡积分,采用了解析的矩函数方法进行计算,所得结果具有较高的计算精度和效率。数值算例结果表明了大型水平接地网接地参数计算中该方法的正确性和高效性。该方法不涉及积分核函数的复指数拟合过程,计算方案简洁,可应用于实际地网的设计和参数分析中。

With the increase of grounding network areas, the parameter calculation of a grounding network is increasing, which heavily needs the fast calculation of the grounding grid characteristics in the horizontal layered soil. In this paper, the method of complex integral path is used to realize the calculation of Green Function when the horizontal distance is greater than the vertical distance. This method transforms the Bessel function into the exponential function with a quick attenuation factor, and then obtains the result via the numerical integration, which has high calculation accuracy and efficiency. In the meantime, for the finite length interval, an analytical moment functions are utilized to accelerate the quadrature process. For the calculation of resistance matrix in a large horizontal grounding grid, compared with the existing literature results, it is proved that the method proposed in this paper can be applied to the design and the parameter analysis of the actual grounding grid, due to the fact that there is no process involving fitting the kernel function with the complex exponentials.