The PRS-721 is a digital breaker protection device and can be applied for all kinds of busbar arrangement of various voltage level ranging from 1000kV to 110kV. By default, breaker failure protection, voltage protection, overcurrent protection, stub protection, broken conductor check and automatic reclosing function is taken as the standard function of PRS-721.When PRS-721 is mainly designed for protecting “T” zone of one and a half breakers arrangement. The device comprises of circulating current Protection and feeder line end fault protection.This relay can sample the analog values from the traditional instrument transformers, or receive the sampled values from the electronic current and voltage transformers (via a merging unit). The binary inputs and outputs of this relay can be configured according to the demands of a practical engineering through the PRS IED Studio configuration tool auxiliary software, which can meet some special requirements of protection and control functions.This relay can fully support the IEC61850 communication protocol and GOOSE function, and can completely meet the demands of a modern digitalized substation.
