Cost reduction and minimization of land based on an accurate determination of fault current distribution in shield wires and grounding systems

The authors describe the methodology used in a careful analysis of the fault current distributions in neutral metallic paths, power system protection requirements, and ground potential rise (GPR) evaluations carried out at FPL´s Lauderdale power plant and associate switchyard. These studies resulted in substantial cost savings and land utilization minimization for the power system expansions at Lauderdale plant by confirming that the in-situ expansion and reconfiguration aimed at constructing two electrically independent substations sharing the same site and grounding system is a sound economical alternative to the construction of a new substation and associated significant site preparation and construction costs. The study illustrates, using a real-life installation, the distribution of fault currents and ground potentials along overhead ground wires and neutral conductors connected to a power plant under fault conditions