The National Wind Technology Center features dynamometers that can test 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 test water turbine drivetrains by replacing the rotor and blades of a turbine with a powerful motor. NREL's dynamometer test facilities can validate new drivetrain designs and test 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 testing, and to develop software.
Overall capabilities include the ability to:
- Perform steady-state testing to determine a turbine's power curve
- Conduct highly accelerated tests 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 testing 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 0–216 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.