An Impedance Estimation Method for High Ohmic Ground Faults in Compensated Distribution Grids

This paper proposes a new method to determine the impedance of single phase high impedance ground faults in compensated power grids. The estimation of the ground fault impedance is achieved by switching a reactance parallel to the Petersen coil and analyzing the resulting damping of the system. The value of the damping rate, can be used to determined whether a ground fault is active and how high the impedance of that ground fault is.