Synchronized phasor measurement in protective relays for protection, control, and analysis of electric power systems

The advent of satellite-based time-keeping systems and advances in computer technology have made possible protective relay sampling synchronization within 1 mus. These relays can now provide synchronized phasor measurements that eliminate the need to have different devices for protection, control, and electric power system analysis for system-wide applications and traditional protection applications. System-wide applications have different sampling and signal processing requirements than do traditional protection applications. These different requirements normally are addressed with different devices, one device for each specific function. This paper proposes combining the aforementioned applications in a single device with a flexible signal processing system. The addition of synchrophasor measurement in a protective relay results in increased power system reliability and provides easier disturbance analysis, protection, and control capabilities than do approaches with different information sources.