Abstract
The paper presents a methodology for more precise determination of earth currents in networks grounded with Petersen coil. This calculation is necessary to establish the directional zero sequence overcurrent relay settings, which are sensitive to these types of faults. Is present the voltage and current determination at the fault place and at the protection installing place. All analyzes are based on a concrete example, using a power distribution networks of 20 kV cable lines.
Cuvinte cheie
earth fault currents
Petersen coil
zero sequence current