At NREL’s Flatiron Campus, cutting-edge research focuses on testing emerging wind technologies and accelerating their market availability. Researchers conduct a series of tests and accurate transient simulation studies to understand how individual wind turbines handle grid disturbances. Field testing wind turbines can be both expensive and time-consuming.

RMH’s Controllable Grid Interface Row 1 (CGI-1) test system design supports this process by significantly reducing the time and cost of testing wind turbines by enabling controlled laboratory testing. The 9 MW CGI combines hardware and real-time control software, operating with existing 2.5 MW and 5 MW dynamometer facilities (also partially designed by RMH). This setup simulates grid disturbances on wind turbine terminals and estimates the impacts of turbine responses on the grid. The CGI test system project created the first U.S. test facility with fault-simulation capabilities and the only system globally fully integrated with two dynamometers designed to work with four types of wind turbines, including the largest wind turbine drivetrains used in land-based markets. The CGI-2 project enhanced the campus’s capabilities by increasing connected grid power from 9 MW to 19.9 MW, complying with local utility requirements.

RMH also designed the electrical and communications infrastructure to connect dynamometers used for testing wind turbine drivetrain components with the grid and fault simulation areas. This infrastructure features ride-through capability and safely withstands abnormal grid conditions such as faults. RMH configured the CGI system flexibly to connect multiple test objects, including utility-scale wind turbines, other renewable energy generation systems like photovoltaic arrays, and grid-scale energy storage units.