Informative Background on the Interoperability Requirements in IEEE Std 1547-2018

This NREL report summarizes the interoperability requirements in the revised Institute of Electrical and Electronics Engineers Standard 1547-2018 (IEEE Std 1547-2018). Additionally, the report provides context and related background concepts for applying advanced interoperability capabilities.

Topics Covered

The report covers topics related to the utilization of interoperability such as:

• Communications protocols
• Utility requirements for monitoring and controlling
• Bulk power system data needs
• Aggregator applications
• Screening criteria.

Key Takeaways

Interoperability requirements are new to the IEEE Std 1547-2018. The requirements in the standard are directed primarily toward distributed energy resource (DER) manufacturers. Yet, if interoperability capabilities are to be applied, additional stakeholders have roles in understanding and implementing these features. Largely beyond the scope of IEEE Std 1547-2018, utilization of interoperability capabilities and methods for implementation are decisions for local jurisdictions.

If interoperability capabilities are enabled, interconnection rules will need to specify which DERs will be required to integrate with communications systems and which communications protocol the area electric power system operator will use at the DER communications interface. Based on lessons learned from the implementation of interoperability requirements in other jurisdictions, an implementation profile could provide beneficial guidance for both utility and DER operators.

Information Exchange

IEEE defines interoperability as "the capability of two or more networks, systems, devices, applications, or components to externally exchange and readily use information securely and effectively."

Hierarchy of Metering, Monitoring, Controlling, and Dispatching

Chapter 1 describes these classes of utility information exchange and their uses in distribution protection, operations, and planning. Generally, DER project size and penetration, as well as voltage class, drive the requirements for monitoring and control. To avoid unnecessary expenses for equipment, infrastructure, and staff, some consideration should be given to optimizing the strategy for utilizing interoperability. Chapter 3.5 offers some sample screening criteria for considering when monitoring and/or control might be required.

Defining Use Cases for Interoperability

While IEEE Std 1547-2018 provides a standardization of the local DER interface, protocols and mandatory information elements (summarized in Chapter 2), the standard does not address the use of this new functionality, specifically leaving these decisions to the authority governing interconnection requests, area power system operators, and bulk power system stakeholders.

The following topics are important considerations when defining use cases for interoperability:

• Timeline for when communications and control might be needed
• Performance level (e.g., accuracy, data-rate/frequency) necessary
• Communications network parameters, including ownership, operation, reliability/availability, and security.