A bus differential protection scheme using real-time synchrophasor data

The common form of bus differential protection is to use either a high impedance differential relay or a biased low impedance differential relay. Bus protection using a feeder overcurrent blocking scheme is also widely used in the sub-transmission and distribution levels due to the high cost of the complete bus differential protection solution. IEEE Working Group C-14 of the Power System Relaying Committee published a report on Use of Synchrophasor Measurements in Protective Relaying Application on April 8, 2013. In this report, it was pointed out that the synchrophasor measurements could be used for bus differential relaying in the near future and provided some guidelines on how to realize the bus differential protection using phasor measurements. This paper studies this novel bus differential technology of using synchrophasor data to realize fast, reliable bus differential protection. Together with other bus differential protection, it can satisfy the requirement for bus protection and provide an option for a low-cost complete bus protection system.