The Energy Department’s National Renewable Energy Laboratory (NREL) added a new 5-megawatt (MW) Dynamometer Test Facility at its National Wind Technology Center (NWTC) outside Denver. The new facility dramatically expands the capability of NWTC engineers and their industry partners to verify the performance and reliability of wind turbine drivetrain prototypes and commercial machines.
The facility is capable of testing drivetrains up to 5 MW—large enough to test virtually any land-based turbine—and employs dynamically variable loading capabilities that will allow researchers to better simulate conditions a turbine might experience in the field.
A dynamometer system replaces the rotor and blades of a wind turbine and allows researchers to control the turbine drivetrain’s mechanical and electrical systems while simulating normal and extreme operating conditions. This testing previously has been done under torque loads only. The new state-of-the-art facility features a non-torque loading system into the testing regimen. A hydraulic device simulates both the rotational and bending loads that a wind turbine rotor places on a drivetrain.
The system features a 6-MW motor, which provides the power to a turbine during testing. The motor turns at very high speed and low torque. The motor drives a gearbox, which transforms the output to the high torque and low speed that is appropriate for a wind turbine drivetrain.
Dynamometer testing is used by industry to confirm proper operation and reduce the risk of deploying wind turbine prototypes before they are put into service. Reproducing operating conditions in a laboratory environment can verify the performance of a turbine’s systems, including generators, gearboxes, power converters, bearings, brakes, and control systems.
The first tests being done at NREL’s new dynamometer facility are on a 2.75-MW wind turbine the Energy Department acquired in partnership with General Electric (GE). The GE system is being used for the calibration and commissioning of the testing equipment in the facility, which will also provide the industry partner with useful data on this particular turbine model.