一种地网腐蚀故障诊断的新算法

Novel Algorithm for Fault Diagnosis of Grounding Grid

为解决地网腐蚀的定位问题,基于新标准对接地网在概念上的变化,提出并解决了基于场路结合的不等电位模型的地网腐蚀故障诊断的方法;针对地网腐蚀时的导通电阻变化,验证计算了地网腐蚀时地表电位分布及最大跨步电势、接触电势发生处的位置。通过编程实现了数值模型的计算机求解,其方法是通过求取地网各支路散流电流及节点电位来获得各支路的导通电阻值,并通过腐蚀前后各支路导通电阻值的变化来判断地网的腐蚀情况。同时,该模型对于入地电流频率在几十kHz下仍可考察地网的运行情况。实际结果表明,本文方法与试验结果吻合,具有较高的可信性。

Based on the concept that the earth resistance of the grounding device is an important parameter, but not the only and absolute parameter, the authors studied the corrosion fault diagnosis of the grounding grid, proposed a node voltage method with unequal potential model which combined with electromagnetic field and circuit theory, and performed grounding grid corrosion fault diagnosis. Furthermore, the lead resistance computation was proposed, and the potential distribution as well as the occurrence place of the max. step voltage and touch voltage of corrosion grounding grid was calculated. Computer solution of numerical model through the programming was realized, the method can get the electric resistance value through calculating leakage current and node potential in any branch of grounding grid. The branch electric resistance values before corrosion and after corrosion were compared to judge the corrosion degree of grounding grid. Meanwhile, this model, for entering grounding current frequency of dozens of kilohertz, can investigate the running situation of the grounding grid. The experimental comparison shows this method has a higher credibility.