Novel algorithms for earth fault indication based on monitoring of shunt resistance of MV feeder as a part of relay protection

Novel methods for very high-resistance earth fault identification and location in isolated or high impedance earthed distribution systems have been developed. The novel indication algorithms are able to detect and locate faults up to some hundreds of kilo-ohms. These algorithms were implemented in a microprocessor-based feeder terminal. The indication methods have proven to be very appropriate for the implementation and the preliminary results from the field installation and field experiments are promising.