STUDY ON FEEDER GROUNDING FAULT PROTECTION BASED ON ZERO SEQUENCE ADMITTANCE

New principle for feeder grounding fault protection based on zero sequence admittance is presented in this paper.Criterions for the line ground relay with zero sequence admittance are also discussed.This principle can be applied easily in feeder relays and implemented in local control units (such as FTU) by measuring the zero sequence fundamental voltage and current.It improves the performance of traditional grounding fault relays in difficult implementation and poor reliability.This principle is verified by EMTP simulator.Results show that this protection scheme has high precision and can be used to detect high impedance grounding faults.