Towards timely intelligence in the power grid

One of the key lessons learned from the 2003 Northeast Blackout in the United States was the need for improved grid timing and synchronization. The problem began as an isolated issue, but cascaded through the Northeastern grid. Timely situational awareness would likely have contained the area affected by the blackout. To attain situational awareness over a large scale requires synchronized time. Synchronized time enables merging data from remote sources, maintaining tolerable measurement uncertainty, and forensic analysis to build knowledge on preventing future problems. Phasor measurement units (PMUs) rely on global synchronized time to consolidate measured data points from remote substations on the grid allowing situational awareness and the ability to anticipate potential issues and take the necessary corrective actions to prevent or minimize loss of power. Global synchronized time is currently being provided by the Global Positioning System (GPS); however, potential issues and limitations motivate another precision timing solution. Network time synchronization, particularly IEEE 1588 Precision Time Protocol (PTP), can reliably sustain sub-microsecond time precision. The National Institute of Standards and Technology (NIST) has developed a timing testbed to characterize, assess, and monitor the performance of network timing in various test scenarios. Furthermore, in conjunction with the NIST Synchrophasor Lab, a prototype IEEE 1588 PMU was built and tested. The metrics, software and test methods developed would enable substations, manufacturers of power systems equipment, and IEEE 1588 certification labs to ensure their 1588 network and products can meet the requirements of next-generation power grids. The paper provides the motivation and applications for the NIST timing testbed, and highlights the metrics, test methods and software tool that have been developed.