The Use of Synchrophasors for Wide Area Monitoring of Electrical Power Grids

This paper describes the latest developments in the wide area monitoring of electrical power grids, based on IEEE C37.118.1-2011 synchrophasor measurements. It outlines the fundamentals of synchrophasor systems, and focuses on the latest technological advancements and practical applications deployed in the existing and emerging power grids. With the emphasis on higher utilization of power systems while maintaining high systems reliability and availability, dynamic monitoring of the power systems’ operation remains to be important, and challenging. Analysis of recent blackout events showed multiple systems vulnerabilities and improvement areas. The use of synchrophasor measurements system-wide or on a smaller scale could provide significant assistance and risk mitigation to these tasks. Introduction of synchrophasor measurements as well as advances in communications and processing power made it technically feasible to monitor the stability of the power system on-line in near real-time, using a wide area perspective. Stored synchrophasor data can also be used for off-line analysis of past events, or serve as an input for calibration and verification of the dynamic models of systems components. The main aspects of both on-line monitoring and off-line analysis are summarized in the paper. Synchrophasor-based applications discussed in the paper include phase angle monitoring, voltage stability monitoring, line thermal monitoring, power oscillation monitoring and phasor-enhanced state estimation. The applications that are currently in operation, planning and pilot project stages will also be presented. Finally, practical considerations on projects execution are covered, including guidance on Phasor Measurement Unit (PMU) functionality, locations, hardware selection, time synchronization options and common challenges in phasor deployment.