Investigation of ground impedance measurement techniques up to 1 MHz frequency in urban dense power substations

This paper aims to study the ground impedance measurement on the mesh network of power. Generally, the ground and its connections are modeled using an impedance consisting of resistance, capacitor, and inductor. The junction point resistance resulting from the specific resistance of the junction point to the ground is applied in the studies related to the power network. The values of capacitance and inductive capacity are also considered in the studies relating to high frequencies, lightning, and switching. First, the electric model of the soil is determined, and then the electric model of meshed networks connected by copper wires is modeled. Finally, the electric model of grounded electrodes is also acquired in various points of the ground network. All the simulations are performed using MATLAB/Simulink. The measurements are taken practically and compared at Payam power substation, Dezful, through various approaches. The step and touch voltages are also measured using various techniques considering the necessity for the safety of equipment and staff of the power substation.