Cogent Assessment of Safety Parameters in Design of Microgrid Grounding System

Microgrids (MG) are generally built up near the load centres. With augment of considerable number of MGs in the present power system, it becomes indispensable to cogently estimate the safety parameters while designing its grounding system. This is mainly due to the closeness of MG grounding to other nearby grounding systems. For this purpose, an interactive mathematical model between the two nearby grounding designs (including MG grounding) is exemplified. It shows that if mutual interaction between the two nearby grounding design are not considered then it leads to overestimation of safety parameters such as touch voltage, ground potential rise and grounding grid resistance. This causes un-necessary expenditure on safety design. Results obtained through mathematical model are substantiated by simulations results acquire through finite element method and are found to be favorable. Further, ground potential distribution profiles through FEM are also found and are in conformity with mathematical model.