Monday, January 4, 2016
The grounding technique depends primarily on how the system is earthed, and configuration as well as the voltage. This varies between country, and local practices, but sees below for a general idea.
MV systems like 3.3, 6.6, 11, and 33kV are generally impedance earthed so the earth fault current is limited, which means that the grounding design is relatively straightforward unless it's a small rural substation fed via overhead lines.
HV systems like 66, 132,230, 380kV te ...