NIST releases smart-grid interoperability standards

The National Institute of Standards and Technology (NIST) advised the Federal Energy Regulatory Commission (FERC) that it has five foundational sets of standards for smart-grid interoperability and cybersecurity ready for consideration by federal and state energy regulators, said George Arnold, NIST’s national coordinator for smart grid interoperability. The standards address interoperable computer language used to control and communicate with infrastructure installed on the smart grid — a nationwide electric power system that enables two-way flows of energy and information. The software-based standards have been developed to help electric utilities build out flexible smart grids and to provide manufactures with the needed requirements so disparate systems can be integrated into the grid and interoperate, Arnold said.

“Four of the standards deal with information models and define the computer language used by different devices and systems in a substation, for example,” he said. “The fifth standard deals with cybersecurity.”

The Energy Independence and Security Act of 2007 directed NIST to coordinate the development of communication protocols and other standards to achieve an interoperable smart grid. Arnold said this specific set of standards defines the data format for communication between the computer systems that control or receive measurements from smart-grid devices. They also define the application protocols for exchanges of information between control centers on the grid.

“[The standards] allow for measurement data to be communicated through a standardized language, allowing electric utilities to integrate information systems into their network from a variety of vendors and to interoperate,” he said. “So for example, if you want to have an application for wide area situational awareness conditions on the grid, these standards would provide the common language that would allow data from different substations to communicate that information through a common database.”

Arnold said the standards also provide the data language needed to support smart-grid automation.

“So if you are automating the distribution grid, putting in relays and devices that allow for automatically restored power after faults, these standards provide the computer language that allows a computer system to control these devices,” he said.

Arnold said there still are hundreds of standards that will need to be developed to ensure interoperability throughout the smart grid. But he expects it will take at least five years to flush out the standards to a “reasonable state of completion.”

The standards and their functions are as follows:

• IEC 61970 and IEC 61968: Providing a Common Information Model (CIM), necessary for exchanges of data between devices and networks, primarily in the transmission (IEC 61970) and distribution (IEC 61968) domains.
• IEC 61850: Facilitating substation automation and communication as well as interoperability through a common data format.
• IEC 60870-6: Facilitating exchanges of information between control centers.
• IEC 62351: Addressing the cyber security of the communication protocols defined by the preceding IEC standards.