Field demonstration of networked microgrid distributed control technologies

On the last week of September, a team led by the Pacific Northwest National Laboratory (PNNL) completed the final field demonstrations for the Citadels project on an operational electrical system at the Electric Power Board (EPB) of Chattanooga. Other members of the project team included Commonwealth Edison (ComEd), Open Energy Solutions (OES), Lawrence Livermore National Laboratory (LLNL), Oak Ridge National Laboratory (ORNL), Sandia National Laboratory (SNL), and Washington State University (WSU).

This field demonstration marked the first time a consensus algorithm was successfully deployed to enable a group of networked microgrid controllers to collaboratively control the voltage of operational primary distribution system. This included executing a black start of an all inverter-based microgrid.

Citadels is a U.S. Department of Energy (DOE) Grid Modernization Laboratory Consortium (GMLC) Project to demonstrate how microgrids can self-assemble to support bulk system operations and improve the resilience of critical end-use loads during outages and blackouts.

In addition to demonstrating how networked microgrids can inject reactive power to the grid, researchers were also able to test the capacity of containerized applications to run offline simulations using commercial off-the-shelf hardware. This allowed them to conduct complex operations, such as networked microgrid self-assembly, without interrupting service to thousands of customers.

“Overall, the demonstration was extremely successful with each of the events executed as planned,” said Kevin Schneider, PNNL laboratory fellow and Advanced Grid Institute (AGI) joint appointee, “this demonstration validates how distributed controls can be successfully deployed and coordinated with centralized systems.”

WSU’s contribution to the project is managed by Professor Anamika Dubey, also an AGI joint appointee, and focuses on coordinating centralized and distributed control for different modes of networked microgrid operations. WSU is also developing a comprehensive power-communication-controls co-simulation model to support the testing and validation activities for applicability to other regions of the nation.

Citadels uses Open Field Message Bus (OpenFMB), a reference architecture for security and interoperability that enables optimal centralized operations during normal conditions and distributed edge operations during extreme events.

The Citadels field demonstration is just one example of how power systems are transitioning from a purely centralized control structure, to one in which control is becoming more common on the edge. The integration of edge control will be critical as the nation’s electrical infrastructure increasingly electrifies end-use loads, becomes more reliant on renewable generation sources, and increases the number of generation sources at the grid edge.