Designing Safe and Reliable Grounding in AC Substations With Poor Soil Resistivity: An Interpretation of IEEE Std. 80

IEEE Std. 80 “IEEE Guide for Safety in AC Substation Grounding” is most commonly used in the design of substation ground grids and is the basis for today´s commercially available software. This paper discusses an alternate design approach for substation grounding in areas that have high soil resistivity. It discusses various methods for designing a substation grounding system without changing the characteristics of the soil with additives or adding ground wells to establish a low resistance to remote earth. An interpretation of the equations and a better understanding of IEEE Std. 80 allow the engineer to provide a cost-effective, safe, and reliable grounding system design when poor soil conditions exist.