Analysis of Earthing System in 132kV Substation for Improved Safety (Case Study: First Independent Power Limited, FIPL Omoku)

Abstract

This study analyzes the earthing system of a 132kV substation for improved safety, using the First Independent Power Limited (FIPL) Omoku substation as a case study. The substation's ground/earthing grid consists of conductors in horizontal arrangements linked to vertical rods, primarily dissipating high fault-related currents. The 132kV substation was selected for this analysis to assess safety, particularly about the ground grid. The grid mesh analysis used IEEE 80-2013 methods to evaluate critical ground grid parameters. The ETAP-19 software, featuring enhanced capabilities over previous versions, was used for the analysis. The first case study highlighted issues with the existing ground grid mesh. In the second case study, a newly designed ground mesh for the substation was achieved using updated methodologies and modern analysis techniques. The third case study involved creating a new ground mesh for an Extra High Voltage (EHV) substation at 132kV. Finally, a comparison was made between the mesh designs in all three cases to assess their efficiency and effectiveness. Recommendations on the best methods for future ground grid designs in EHV substations were provided.