Design Of Ac Substation Grounding System

The purpose for this paper is to understand the basic foundation used to safely design a substation grounding system for AC systems. The following criteria that needs to be address regarding the grounding system includes field data from the site such as soil analysis, the earth and grid resistance, maximum fault current, the conductor material, size, and joining methods, ground rods, resistivity of the soil, common fault types, the hazard tolerable shock voltage consisting of touch, step and mesh voltage, and tolerable body current limits. Based on the formula and criteria from the IEEE Standard 80-2000, calculations will be used to determine whether the substation grounding is safe by design. The information provided here will help to ensure a safe environment for those working in or around the substation while protecting equipment from dangerous electrical shock under normal and faulted condition.