Grounding Grid Corrosion Diagnosis and Uncertainly Analysis of Branches

Abstract

A hierarchical model of grounding grid is presented, based on which, a testability evaluation method is put forward. The branches are classified into clear branches and uncertain branches according to the testability of them. The concept of uncertain branch group is defined, which consists of related uncertain branches. The prototype of an uncertain branch group is also defined, the branches in which are all clear. The nonlinear incremental diagnosis equations are established and solved by an iteration method, with which, the resistances of clear branches can be directly determined. A dichotomy based method is proposed to evaluate the resistance ranges of uncertain branches for each uncertain branch group, respectively. Experiments are made on a grounding grid with sixty branches, the results of which show the correctness and feasibility of the proposed approach.