任意块状结构土壤中接地的边界元法分析

Boundary Element Analysis on Grounding Systems in Soil With Arbitrary Massive Texture

为计算分析任意块状结构土壤中的接地问题,根据边界元法基本原理,给出了一种通用算法,详细介绍了该算法的原理和计算公式。该算法以边界面元的电位和导体元的电位梯度为未知数,列写并解线性方程组,进而得到各接地参数。运用Matlab编程计算简单块状结构土壤接地模型,与CDEGS软件计算结果的比较表明了该方法的正确性。针对实际中经常出现的高台模型,给出了通用算法的计算结果,并对高台模型增加垂直接地极以减小接地电阻进行了计算分析。算例计算结果表明,该算法计算速度较快,可用于任意块状结构土壤中任意接地模型的计算分析。

To calculate and analyze the grounding system in the soil with arbitrary massive texture, according to the principle of boundary element analysis a general algorithm is proposed and the principle as well as calculation formulae of the proposed algorithm are presented in detail. In the proposed algorithm, the potentials of boundary surface elements and the potential gradients of conductor element are unknown numbers, the linear equations are listed and solved by the given algorithm to attain all parameters of grounding system. By use of Matlab, a simple grounding system in the soil with massive texture model is modeled and calculated, and the comparison of the calculated result with that by CDEGS software shows that the biggest relative error of the grounding resistance is 1.266% and the average error of the surface potential is 4.278%, thus the proposed method is correct. In allusion to the model of hathpace that often appears in practice, the calculation results by general algorithm are given and the occasion of adding vertical grounding electrodes to hathpace model to reduce grounding resistance is analyzed and calculated. Results of calculation examples show that the proposed method possesses higher calculation efficiency and can be applied in the calculation and analysis of arbitrary grounding models in the soil with arbitrary massive texture.