The National Wind Technology Center features dynamometer research facilities that can certify water power-take-off systems for turbines and some wave devices over a wide range of capacity ratings—from 1 kilowatt (kW) to 5 megawatts (MW).
Dynamometers can validate water turbine drivetrains by replacing the rotor and blades of a turbine with a powerful motor. NREL's dynamometer research facilities can evaluate new drivetrain designs and assess a variety of components and subsystems—including generators, gearboxes, mechanical or electro-dynamic brakes, power electronics, control systems, and software. Manufacturers and design engineers can use our facilities to study system performance and the integration of generators and power electronics with the electric grid, to perform accelerated lifetime certification, and to develop software.
Overall capabilities include the ability to:
- Perform steady-state evaluation to determine a turbine's power curve
- Conduct highly accelerated assessments in which the turbine is intentionally overloaded to determine its useful operating lifetime
- Use "model-in-the-loop" techniques to emulate various system parameters with computer simulations that are operating in real time.
Capabilities specific to the larger dynamometers include the ability to:
- Apply nontorque loads, including radial and thrust forces
- Apply yaw or pitch moments of up to 7.2 millinewton-meters
- Connect to the controllable grid interface so that researchers can better understand how turbines react to grid disturbances.
When it comes to evaluating drivetrains, one size does not fit all. NREL has three dynamometers of varying sizes to offer flexibility to their partners.
This dynamometer employs a 300-horsepower (hp) variable-speed induction motor with AC grid connections of 120, 240, and 480 volts (V) and a maximum apparent power of 250 kilovolt-amperes (kVA). It can also simulate battery charging at 0216 V DC and a maximum apparent power of 20 kVA.
The 2.5-MW dynamometer features a 3,351-HP, 415-amp AC induction motor with variable frequency drive that can connect to the grid at 575, 600, 690, and 4,160 volts AC.
The 5-MW dynamometer features an 8,000-hp AC induction with variable-frequency drive that can connect to the grid at 13,200 V AC. See the NREL fact sheet on this relatively new dynamometer.