Substation grounding transfer of potential case studies

Industrial substation grounding studies usually assume a simple isolated substation, follow the routine IEEE 80 design and analysis procedures using the software tools bundled with the power systems analysis suite of choice, and carry on with the rest of the project. However, there can be complications to substation grounding designs. This paper discusses two case studies where a ground fault in one substation generates a voltage which is transferred to other areas. The issues are assessed using common software tools supplemented with simple spreadsheet calculations. Some common limitations of the standard software tools, when applied to these more complex problems, are discussed in this paper, along with appropriate work-arounds. Mitigation methods are discussed.