Dr. Rick Blum recently spoke at the IEEE-SA/NIST Timing Challenges in Smart Grid Workshop.
Dynamic distributed measurement and control systems are time sensitive. In distributed control where scheduling of resources, seamlessly orchestrated coordination, and hard deadlines; must be met, measurement data, state estimators and control commands are temporally valid for a specific, sometimes brief, duration. In order to provide the common time reference for correct temporal behavior, all systems must be synchronized to a traceable time and frequency source.
In the North American power grid, where each interconnection stretches over a large spatial expanse, achieving correct timing can be challenging. Timing needs include one microsecond synchronization to a traceable time and frequency reference for data fusion. Issues include, but are not limited to, GPS and communication infrastructure as well as concerns for reliability and resilience; if a reference source becomes unavailable.