Optimized Renovation Strategy for Grounding Systems in Grid Substations: A Cost-Effective Simulation Model Using CYMGRD

The grounding grid in high-voltage substations is essential for ensuring personnel safety, protecting equipment, and maintaining power system reliability. Rapid expansions in electrical infrastructure, including new interconnections, power plants, microgrids, and transmission lines, have increased the stress on grounding systems in aging substations. Older grids are particularly susceptible to elevated fault currents, increased Ground Potential Rise (GPR), and hazardous touch and step potentials due to corrosion and environmental wear, often exceeding original design tolerances. While new grounding designs are well studied, research on optimizing existing grids remains limited. Unlike newly designed substations, retrofitting existing systems faces significant constraints, such as restricted access to live areas, load-management demands, and substantial safety concerns. This study examines these challenges by analyzing a high-voltage substation in Bangladesh, utilizing the CYMGRD simulation tool to design an optimized and economical grounding renovation. Results show that critical safety metrics-including GPR, touch and step potentials, and fault currents-are maintained within safe limits. This research highlights an optimized grounding upgrade approach that addresses both technical and financial limitations in aging substations, offering valuable insights for enhancing grid safety in response to evolving infrastructure demands.