Abstract:
Main purpose of this paper is designing safe and cost effective grounding systems for 220/66 KV Hybrid (AIS/GIS) substation situated at such locations where soil of the substation site is not uniform. Standard equations are used in the design of earthing system to get desired parameters such as touch and step voltage criteria for safety, earth resistance, grid resistance, maximum grid current, minimum conductor size and electrode size, maximum fault current level and resistivity of soil. By selecting the proper horizontal conductor size, vertical electrode size and soil resistivity, the best choice of earthing design for safety can be performed.
