Research on Corrosion Diagnosis Method of Substation Grounding Grid Based on Surface Magnetic Induction Intensity

Substation grounding grid system is the most important guarantee to ensure the safe operation of electrical equipment. However, the conductor of the grounding grid will be corroded and fractured due to the material. Grounding Grids Corrosion (GGC) diagnosis has become a convenient method to solve the fault of the grounding system. To further improve the ability of traditional GGC technology to diagnose and locate fault points, this study uses the surface magnetic induction intensity (S-MII) detection method to detect the grounding grid based on the traditional GGC detection principle. This method first studies the different degrees of S-MII of GGC under a certain excitation current frequency; then, the frequency of the grounding grid is changed to study the different degrees of S-MII of GGC under different excitation current frequencies. Finally, according to the Waveform Difference Recognition Algorithm (WFDRA), the S-MII waveform is analyzed and the GGC position is determined. At the same time, a diagnosis method of local conductor corrosion degree of grounding grid based on corrosion function is proposed to classify the corrosion degree of grounding conductor. The experimental results show that the GGC diagnosis method proposed in this study can conveniently diagnose the GGC position and judge the corrosion degree of the grounding grid. At the same time, it also shows the effectiveness and accuracy of the method in diagnosing GGC.