This article presents recent patents and advances on the fault diagnosis for grounding grid. Electromagnetic and chemical methods are applied to the fault diagnosis for grounding grid, furthermore the new square-wave technology earns widespread respect in fault diagnosis fields. The paper presented a method of the fault diagnosis for substation grounding grid using the square-wave, based on the analysis on the frequent characteristics of soil and substation grounding grip. The method is verified in calculating simulation, simulating experiments and field experiments to satisfy the needs of power system. Since this method can diagnose the fault of grounding grid by special data mining of the surface potential measurement result, which uses the square power supply, it needs neither the detailed topological structure of the substation grounding grid nor the excavation grounding grip, which would be an obvious advantage comparing to the other fault diagnosis methods nowadays.
Keywords: Fault diagnosis, grounding grid, quare-wave, surface potentia, Anti-corrosion, Grounding electrode., In-Filed configuration, Electrical resistance tomography