Multi-Frequency Neutral Admittance Earth-Fault Protection White Paper

This white paper describes a novel algorithm for feeder earth-fault protection in compensated and unearthed medium-voltage networks, based on multi-frequency neutral admittance measurement combined with a cumulative phasor summing technique. The method provides high sensitivity and secure discrimination between faulty and healthy feeders, even during challenging faults such as restriking earth faults, and can be applied in either tripping or alarming mode.