AUTHORS: Adel Z. El Dein, S. Yassen
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ABSTRACT: The propose of the protection system is to protect the equipment in the power substation against large fault currents. One of the important protection system is grounding system. This paper presents a comparison between two designs of the grounding grid. The first one is a square type grounding grid and the second one is a circular type grounding grid. Firstly, the two types are assumed to be had the same total area enclosed by the ground grid, and secondary, the two types are assumed to be had the same length of the total grounding grid conductor. The parameters under study are: the grounding resistance, step voltage, touch voltage and earth surface potential. The charge simulation method (CSM) and the image method are used within this study, and the effects of the parameters such as: soil resistivity, depth of grounding grid, number of meshes and presence of the vertical rods, on the performance of grounding grids are taken into account. Finally, the validation of the simulation method is done by comparing the simulation results with the experimental results obtained in this study
KEYWORDS: Charge simulation method, Earth surface potential, Grounding grid, Grounding resistance, Image method, Step voltage, Touch voltage
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