Detection of resistive single‐phase earth faults in a compensated power‐distribution system

This paper proposes several algorithms to detect very resistive, permanent (i. e. non‐transient) single‐phase earth faults in compensated MV distribution systems and to identify the faulty feeder. These algorithms analyse the variation of the parameters of the system and of its electric steady‐state quantities, in particular the residual currents of the feeders. In a first part, the impact of a resistive earth fault on these quantities is deduced. The algorithms enable a detection of permanent resistive earth faults of up to 100 k and identify the concerned feeder. A verification of these algorithms was possible by experiences.