Safety Parameters of Grounding Devices at an Electric Power Plant

Grounding provides safety and in some cases a return circuit for load currents and also an uniform distribution of the voltage on the surface of the earth at power plants. If grounding conductors are damaged, it may cause unintended protective relay operation causing feeders to be tripped. It can also result in failure of the grounding device itself, secondary circuits’ cables and structural elements. The circuits may attain unacceptable voltages when short-circuit fault currents occur in these devices. This paper proposes analysis of possible values of safety in terms of Touch and Step Voltage under malfunctions of electric power plants and damaged horizontal elements of the grounding devices. The information described in the article can be referred to an electric power plant with the grounding device made as a grid with a number of meshes in it.