Hardware Testbed Boosts Progress Toward Sustainable, Reliable Power Systems

Achievement date: 
2017
Outcome/accomplishment: 

The University of Tennessee-Knoxville (UTK)-operated electric grid emulator hardware testbed (HTB) has gained significant maturity, flexibility, and usability that is enhancing research efforts to evaluate the impact of innovative technologies on the operation of large future power grids. These advances enable testing of different power system architectures as well as integration and demonstration of key technologies on power grid monitoring, control, actuation, and visualization that will contribute to better performance and higher efficiency of North America’s power grid system. The testbed and research are initiatives of the Center for Ultra-Wide-Area Resilient Electric Energy Transmission Networks (CURENT), an NSF-funded Engineering Research Center (ERC) that is headquartered at UTK.

Impact/benefits: 

The advances have enabled CURENT’s HTB to run multiple simultaneous control functions to demonstrate their interoperability and compatibility and to demonstrate them in a single complete system. Among the improvements is redesign of the HTB cabinets and software to be modular so that the system can be converted to emulate different systems much more readily (in a few minutes) because significant cabinet wiring rework or software reprogramming are no longer required. In addition, the HTB now has a wide range of emulators to capture the behavior of different parts of the electrical system, several of which have been combined so that they can run on a single power inverter (which changes direct current to alternating) to provide more flexibility and be able to represent more buses connecting generators to transformers. A hybrid current-control and voltage-control interface that allows the HTB to interface with real time computer systems such as an RTDS or the LTB has also been developed and tested.

Explanation/Background: 

CURENT’s testbeds use integrated data from three major U.S. power transmission grid models: The Eastern Interconnected (EI) System—from the Atlantic Ocean to the Rocky Mountain states; the Western Interconnected System—managed by the Western Electricity Coordinating Council (WECC) for states west of the Rocky Mountains; and, the Texas Interconnected System—managed by the Electricity Reliability Council of Texas (ERCOT).

The testbed has been used to emulate a 3-area system with multi-terminal high-voltage direct current (HVDC) model overlays that provide a good representation of offshore wind power in northeastern North America. It has also been used to emulate a 4-area system that captures the behavior of a future system in the western United States with a multi-terminal HVDC overlay and high penetration level of renewable energy (80%) and storage.