Report on NASPI 2014 Survey of Synchrophasor System Networks

The NASPI (North American SynchroPhasor Initiative) working group brings together power engineers and other people from electric utilities, from power equipment vendors, and from academia. NASPI's objective is to improve the reliability, throughput, efficiency, and economics of the electric power grid by accelerating the widespread deployment of devices called PMUs (Phasor Measurement Units). A PMU makes fine-grained time-synchronized measurements of the electrical state of a particular point on the grid. This data is streamed in real-time to grid control rooms, for recording and analysis by a variety of applications. The applications employ complex and sophisticated algorithms to convert PMU field data into high-value operational and planning information. Today there are almost 2,000 PMUs deployed across the US and Canada, and a diverse set of synchrophasor networks have been built.

Within NASPI, the NetSys (Network Systems) group of the Data & Network Management Task Team (DNMTT) is concerned with choosing technology to meet the reliability and latency requirements for networks used to stream PMU data. At the request of NASPI leadership, the NetSys group surveyed current (2014) practice for wide area networking of PMU data by 25 operational power entities of the North American electric power industry. The survey focused on wide-area networking for real-time streaming of measurement data collected by PMUs in substations and delivered to control room and off-line applications. NASPI has recently published a technical report [1] on this survey and its implications. USC’s Information Sciences Institute Fellow Bob Braden was the NetSys group team lead for the survey and reporting efforts. The complete report’s results and findings are posted at within the News Flash box.

The survey was designed to collect fairly detailed information about current synchrophasor network design and operational practices. It was made available in Fall 2014 to all interested NASPI members, to respond on a voluntary basis. The report offers useful information about today’s synchrophasor networks on some network design and functionality issues. The aggregated survey answers address the topics of WAN technology and service provision, synchrophasor data uses, data delivery standards, various network monitoring and management provisions, and more. This report offers useful baseline information that can help current and future synchrophasor network planners design and deliver better and better-tailored synchrophasor networks in the future.

Future synchrophasor networks will need to be highly secure with high reliability and availability with low latency and packet loss. They will need to support multiple types of applications, including real-time visualization, real-time grid protection and closed-loop control, real-time diagnostics and operator decision support, and off-line engineering and forensic analysis tools. As currently implemented, most of the existing synchrophasor data networks cannot support these requirements, which are more demanding than the Internet's best effort service.

The electric grid is a physical system. Coupling this physical system through PMUs to the data distribution network results in a cyber-physical system. C-P systems are a current topic of much interest in the network research community (see e.g. [2]) and to ISI's DeterLab project in particular (see [3]; [4]).

[1] "NASPI 2014 Survey of Synchrophasor System Networks - Results and Findings”. NASPI Data and Network Management Task Team, Network Systems Group, NASPI Technical Report, July 2015.

[2] "NIST Cyber-Physical Systems Testbed Workshop"., DETER Blog, February 2015.

[3] "Join DETER at SmartAmerica Expo to Showcase Innovations for Cyber-Physical Systems”., DETER Blog, June 2014.

[4] "NASPI Association to Contribute to Understanding of How DeterLab can Support Research in Cyber-Physical Systems"., DETER Blog, April 2014.

Robert Braden
Internet and Networked Systems Division
USC Information Sciences Institute