California ISO Phasor Application Summary Report (Real-Time Grid Reliability Management PIER Final Project Report Appendix D)

A PIER-funded multi-year project is currently being conducted by CERTS in cooperation with CA ISO aimed at research and demonstration activities of real-time applications of phasors for monitoring, alarming, and control. The proposed applications of phasor measurements will provide the real-time operating staff with the previously unavailable, yet greatly needed, tools to avoid voltage and dynamic instability, and monitor generator response to abnormal significant system frequency excursions.

Perhaps of equal or greater importance, in the near term, the measurement infrastructure will provide California ISO with an alternate, independent real-time monitoring system that could act as an end-of-line backup for failures affecting California ISO’s current Supervisory Control and Data Acquisition/Energy Management System (SCADA/EMS); in the long term, it would become a key element of California ISO’s next generation monitoring system necessary for advanced real time control. Some of the proposed

applications include the use of phasor measurements for wide-area visibility, real-time monitoring and alarming, small-signal stability assessment, frequency data collection, nomogram validation and improvements, improved state estimation, and real-time control.

Phasor measurement technologies are a leading example of a new generation of advanced grid monitoring technologies that rely on high speed, time-synchronized, digital measurements. These characteristics are essential for monitoring real-time grid performance, validating (or replacing) off-line nomogram studies, providing advance warning of potential grid instabilities, and, ultimately, enabling the development and introduction of advanced automatic grid control approaches (such as adaptive islanding).