Research On The Corrosion Diagnosis Method Of Grounding Grids Based On Dispersions Of Media

Grounding Grids is one of the most important measures to ensure safe and reliableoperation of Power system. It was buried in soil for long time, can be corrupted by thecurrent into earth or other electrochemical factors. It’s necessary to find the corrosion.Generally, people compare theoretical and calculated values of some parameter ofgrounding grids, to find corrosion area. Accuracy of this method depends on correctness ofcalculate and effectiveness of experiment. So we should study new method to diagnosiscorrosion of grids.This paper draws on the detection methods of underground pipelines and reinforcedconcrete, which is ground-penetrating radar. The actual demand of diagnosis corrosion ofgrids was taken into consideration. We proposed to use dispersion of different media todiagnosis corrosion. Theoretical analysis, simulation and experiments have been done here.Through theoretical analysis, the parameters of media and high-frequencyelectromagnetic wave propagation was be related. Internal mechanism of medium’dispersion was analyzed according to the dielectric relaxation theory. Based on summary ofdielectric spectroscopy, we proposed a method for our experiment.Corrosions of grids were processed, and their capacitance and resistance weremeasured. We analysis dispersion of corrosion by observing the parameters vary withfrequency. The experiment result shows that capacitance of corrosion decreased asfrequency increased.Dispersion of soil must be study. In this paper, the dielectric properties of soil werestudied using the results of previous researches. The model was established, which hadconsiderate the actual conditions of substation grounding grids.In the last part, a model with small size to describe grid corrosion diagnosis is set upand discussed in ANSYS. In the simulation, the dielectric permittivity and conductivity ofcorrosion are varied with frequency. We found that, medium’s dispersions can affect thesurface reflection wave. This conclusion provides a basis for further research.