Models for the Smart Grid#
Key Message - Models for the Smart Grid
Models aid our understanding of interoperability and other smart grid concerns, and facilitate common language and communication across stakeholders. Evolution in technology and grid architecture in recent years requires an update of these tools.
The NIST Smart Grid Conceptual Model reflects technology and platform-driven capabilities emerging in the Customer and Distribution Domains, as well as the structural reorganization of a system that is more reliant on distributed resources.
Communication Pathways Scenarios are presented to help stakeholders examine how interface requirements might change with different system architectures or control strategies.
These scenarios are not mutually exclusive and allow users to visually examine interoperability considerations that might arise through decisions on technology, operations, or economic structure.
Communications challenges increase with grid complexity, which adds risk to everything from stakeholder engagement to equipment procurement. An ontology for the smart grid is introduced to provide reference language that can be used to clarify communications.
NIST Smart Grid Conceptual domain#
Each of the seven NIST Smart Grid Conceptual Model domains is described in the following table.
| Domain | Roles/Services in the domain |
|---|---|
| Customer | The end users of electricity. May also generate, store, and manage the use of energy. Traditionally, three customer types are discussed, each with its own sub-domain: residential, commercial, and industrial. |
| Markets | The facilitators and participants in electricity markets and other economic mechanisms used to drive action and optimize system outcomes |
| Service Provider | The organizations providing services to electrical customers and to utilities. |
| Operations | The managers of the movement of electricity. |
| Generation Including DER (Distributed Energy Resources) | The producers of electricity. May also store energy for later distribution. This domain includes traditional generation sources and distributed energy resources (DER). At a logical level, “generation” includes those traditional larger scale technologies usually attached to the transmission system, such as conventional thermal generation, large-scale hydro generation, and utility-scale renewable installations usually attached to transmission. DER is associated with generation, storage, and demand response provided in the customer and distribution domains, and with service provider-aggregated energy resources. |
| Transmission | The carriers of high voltage electricity over long distances. May also store and generate electricity. |
| Distribution | The distributors of electricity to and from customers. May also store and generate electricity. |
They communicate between each others with both Communication Flows and Electrical Flows as shown in Figure 1 below.
Four different Communication Pathways Scenarios#
The updated Smart Grid Conceptual Model provides a broad overview of evolving trends in the smart grid but lacks detailed characterization of specific system interfaces. To address this, Communication Pathways Scenario diagrams are introduced, leveraging the domain structure of the Conceptual Model for a more detailed examination of interfaces. These diagrams update earlier mappings and provide visual references for legacy applications and logical interfaces. They include scenarios such as Legacy, High-DER, Microgrid, and Hybrid Communication Pathways, each emphasizing different aspects of the grid. These scenarios are not mutually exclusive and aim to depict specific interfaces and conceptual issues inspired by DOE’s reference grid architectures.
The Legacy Communication Pathways Scenario depicts the Conceptual Model mapping to the overarching electric grid architecture from the previous revision of the NIST Interoperability Framework. It serves as a baseline mapping that also depicts a structure representative of current electric grid systems. Domains and sub-domains show logical groupings of systems and applications. For example, transmission systems such as an Energy Management System (EMS) are shown in the transmission operations sub-domain within the operations domain.
Warning
Is this really legacy? I see DERs in there
The High-DER Communication Pathways Scenario represents current and future grids with DERs providing large amounts of power. In the future, market management functionality may be performed at both the distribution and transmission levels, and market makers such as Distribution System Operators (DSOs) will need to optimize for both economic factors and reliability.
The Hybrid Communication Pathways Scenario is inspired by the reference model for distribution grid control in the 21st century. It depicts a high DER environment with centralized, distributed (non-centralized) and edge functionality. Grid control devices are in the Transmission and Distribution Domains. This diagram is called the Hybrid Communication Pathways Scenario because it depicts a hybrid approach to operational communications that uses both public and private communication pathways.
The Microgrids Communication Pathways Scenario vary in scope ranging from a single premise to those including substations. Ownership and control of microgrids varies, with some owned and operated by consumers and some controlled by utilities that may or may not also own the microgrid. The Microgrid Communication Pathways Scenario depicts two example microgrids, one managed and controlled by a customer, and one managed by a utility.
Simplified view of Microgrid and DER Scenario
An Ontology for the Smart Grid#
The electrical grid is an impossibly large and complex system that has been called the greatest engineering achievement of the 20th century. Beyond the sheer scale of the infrastructure, electrical grids are complex systems of systems (SoS) in which mechanical, electro-mechanical, and electronic control devices must all work together in near-real time with human oversight and intervention to produce and manage the electricity critical to modern society.