Exploration of sustainability of micro grid grounding design in proximity to the pole grounding through experimental measurement of safety parameters

Abstract

Customarily, while designing the micro grid (MG) grounding the impact of close by grounding is not surmised. Due to which their grounding design becomes more flawed as it results in the fallacious computation of safety parameters, evincing the surplus cost to meet the safety standards. Dynamic seasonal condition, if ignored, makes the grounding design even shoddier. Usually, both these stipulations are not well thought out concurrently, which is the need of the hour. To surmount this, here, a practical case of MG grounding having nearby pole grounding is proposed which is examined in diverse seasons in uniform and three layer soil structures by utilizing finite element method (FEM). Substantiation of the results is done with IEEE standard 80–2013. This article also proposes an experimental setup for the measurement of safety parameters of two groundings in proximity to each other. Moreover, results are corroborated through experimental measurements by building the scaled model. With the contemplation of nearby pole grounding in different seasons, apart from reduction in ground potential rise (GPR) and increase in touch voltage (TV), large deviations in GPR and TV, which otherwise gourd observed, is discovered. Also, with consideration of pole grounding in proximity, a large discrepancy in TV with alteration in resistivity of soil and thickness of soil (concerning grid burial depth) are determined in rainy and freezing seasons.