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                                             Design and Analysis of Earthing System for 66/11kV Substation
                                                                             Hnin Su Aye#1, Aung Aung*2
                          #Department of Electrical Power Engineering, West Yangon Technological University, Myanmar
                                                                                 [email protected]
Abstract
This paper presents the design of earthing system for 66kV substation and simulation for calculation of its parameters. In substation earthing system is essential not only to provide the protection of people working and walking within the boundaries of substation under normal and fault conditions but also to maintain the function of the electrical system. This paper will be concerned the floor surface either definitely an effective insulation from earth potential or effectively equipment to a close mesh grid. Design and calculation of grounding grid system in the substation area which the top soil layer resistivity is less than the bottom layer resistivity, the number of ground rod used in the grid because the value of ground potential rise (GPR) is different. Standard formula are used in the design of earthing system to get desired parameter such as soil resistivity, number of earth rod, earth rod spacing, earth resistance, grid resistance, maximum fault current, grid potential rise, mesh voltage and step voltage. The result shows by using MATLAB program. The goals of this paper is to protect human life from danger of electrical shock or death, low impedance path to dissipate lighting short circuit current and to be safe earthing system for substation.
Keywords- Safe earthing system, Earth resistance, Mesh voltage, Step voltage