While the role of the power system remains unchanged, namely, to provide reliable electricity at least cost, how that role is fulfilled is changing as the power system becomes increasingly variable, inverter-based and distributed. The IBR Research Team broadly seeks to identify and address critical research gaps surrounding the reliable planning and operation of the power system under high penetrations of IBRs. The IBR Research Team is divided into two main workstreams: Needs and Services and Tools and Models.

Needs and Services

Ensuring a reliable and affordable supply of electricity requires that the needs of the power system be adequately addressed by grid assets through services. Needs include such things as:

  • Regulating frequency and voltage
  • Locating faults
  • Restoring service after interruption.

The IBR Research Team’s Needs and Services workstream is focused on managing the evolution of power systems’ transition from largely synchronous to IBR-driven. The focus of this work is on the features and capabilities of the inverters themselves, rather than the variability or energy-limited nature of the resources behind the inverter. The development of a cohesive, technology-neutral framework for analyzing the interaction between needs and services in an evolving power system is critical for developing solutions, guiding investments, and formulating research needs. The workstream produced a document that describes the evolving needs and services to maintain a reliable and stable power system where IBRs have displaced synchronous machines as a consequence of a shift from fossil-fuel to variable renewables. The document identifies types of system need categorized as:

  1. those addressing stability and power quality
  2. those addressing security of supply, resilience, and quality of service to end-use customers.

The document defines needs in as technology neutral fashion as possible and does not pre-judge how a particular technology might provide a service to meet a need. Both the need to design IBRs to function within the grid as well as adapting the grid to accommodate IBRs is considered, with the objective of maintaining reliable power at least cost. The intention of the document is not to alter the functioning of the grid, but rather guide the evolution of needs and services as IBRs continue to displace synchronous machines. The “System Needs and Services for Systems with High IBR Penetration document, as it stands, could expand in several directions but, before that is attempted, high-level feedback is sought from experts in the field. Reviewers can provide their high-level feedback using the Needs and Services Deliverable Feedback Form. For more in-depth feedback, reviewers can submit marked-down versions of the document to globalpst@nrel.gov. As the document evolves, further feedback will be sought.

Tools and Models

As IBRs continue to supplant synchronous machines in power systems around the world, the models and tools that system operators use to understand the condition of the grid and plan for future scenarios need to be updated to fully capture IBRs’ dynamic nature. The IBR Research Team’s Tools and Models workstream is focused on identifying critical gaps in the capabilities of current tools and models in use by system operators and planners, as well as identifying the potential for new tools that can adequately describe the behavior of IBR. The workstream focuses on where differences in the nature of IBR and synchronous machines are most likely to impact the validity of existing tools and methods, especially those that would impact planning, operations planning and guidance, and interconnection studies.

The Tools and Models workstream developed an interactive presentation that analyzes a wide range of tools, categorized as “stability tools” (positive-sequence, phasor-based time simulation tools), “physics tools” (e.g. EMT or Protection tools) and “economics” tools (e.g. capacity expansion or production cost models). For each tool analyzed, the presentation provides a list of related terms and brands associated with the tool, the key attributes and main uses of the tool, the relationship of the tool to stability tools, the gaps in the tool with respect to modeling or analyzing IBRs or high-IBR systems, and the maturity of the tool (ranging from widely commercialized to ‘proof-of-concept’). Additional topics for tool and model development are covered, including the need for better ‘meta-tools’ that can be used to pre- and post-process simulation results, provide linkages between tools, and help system operators make better decisions given around when to use a given tool or how to interpret results from a tool.

The IBR Research Team ​Stability Tools Inventory:​ Status and Needs” presentation is currently seeking high-level feedback from experts in the field. Reviewers can provide their high-level feedback using the Tools and Models Deliverable Feedback Form. For more in-depth, specific feedback reviewers can submit marked-down versions of the presentation pdf to globalpst@nrel.gov.