Optimal Design of Grounding System Substation, Case Study : 275/150 kV Sigli Substation

Grounding system is an important role in a substation operation, it should be designed by adjusting the distance of the grid and the length of the ground rod to get the most optimal combination of quality and cost. This paper aims to design the model of grounding system by determining permissible touch voltages and permissible step voltages, and simulating the design model using CymGRD software on 275/150 kV Sigli Substation. The result shows that a 50 kg person can safety be inside and outside of the yard. The step and touch potential transfers are acceptable within the yards with a minimum 0.1 m layer of crushed rocks. The step potential level is acceptable along the troughs.