Design of sub-station grounding system — A case study at PDO, and MZEC, Sultanate of Oman

Design of proper grounding system is very vital for any substation to provide safety and protection to both equipment and personnel. Hither to copper conductors are used for substation grounding in sultanate of Oman and elsewhere. In this paper a case study at Petroleum Development Oman (PDO) and Mazoon Electricity Company (MZEC) is presented to replace copper commercial hard drawn with aluminun 5005 alloy material for all new substation grounding in PDO, MZEC, and all other substations in Oman. It is observed that the use of aluminun 5005 alloy material results in a cost effective solution and technically a viable alternate to copper commercial hard drawn material. The paper presents a design methodology using Excel sheets and Matlab Software. The technical evaluation has been based on touch Potentials, step potentials, resistance of ground grid, etc. It is observed that a cost saving of USD 1190 is achieved at PDO (80.8%) and USD 1030 is achieved at MZEC (78.13%).