Earth network monitoring is a comprehensive detection technology for grounding systems of power, railway, communication, petrochemical and other facilities. The core parameters include grounding resistance (R), conductivity (contact resistance) and soil resistivity (ρ). The grounding system forms a low-impedance path with the earth through metal conductors, discharging fault current in scenarios such as lightning strikes and short circuits to avoid equipment damage or electric shock. The core technology lies in:

  Multi-parameter coupling modeling: The grounding grid is not a single conductor, but a complex network composed of vertical grounding electrodes and horizontal conductors. It is necessary to establish a three-dimensional electromagnetic field model through the finite element method (FEM) or boundary element method (BEM) to analyze the current distribution and potential gradient.

  Dynamic performance evaluation: Grounding resistance is significantly affected by soil moisture, temperature and corrosion. For example, soil resistivity in the dry season can increase to more than 5 times that in the rainy season, resulting in deterioration of grounding performance. Therefore, periodic or real-time monitoring is required to ensure that the grounding resistance meets the standard (e.g. DL/T 475-2017 stipulates that the grounding resistance of a substation is ≤0.5Ω).
  Project significance: In 2020, a coastal substation suffered an abnormal increase in potential during lightning strikes due to corrosion of the grounding grid, which caused the main transformer to burn out. By detecting local resistance abnormalities (>2Ω) in advance through the online monitoring system, such losses can be avoided, with direct economic benefits exceeding 10 million RMB.