A novel approach of grounding grid corrosion diagnosis

To benefit the corrosion diagnosis, the concept of uncertain branch group and its corresponding prototype are defined. A node partition method is presented to divide the intrinsic network into several small sub-networks to solve. A set of linear equations about conductance of the intrinsic branches is deduced based on KCL equations. The nonlinear iteration is avoided. An approach to calculate the resistances of clear branches is presented. The steps to obtain the resistance ranges of uncertain branches based on the branch resistances of the corresponding prototype are described. A grounding grid with sixty branches is given as an example showing that the proposed approach is feasible and has the advantage of only a few tests are needed to meet the requirement of diagnosing a certain part of the grounding grid.