Novel Algorithm for Fault Diagnosis of Grounding Grid
Jianwu Wang · Gao dianya jishu · 2007
Based on the concept that the earth resistance of the grounding device is an important parameter, but not the only and absolute parameter, thes 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.