Days before the holiday season, the Energy Department’s National Renewable Energy Laboratory (NREL) set the wind industry on a new course with the addition of a new 5MW Dynamometer Test Facility at its National Wind Technology Center (NWTC). The new facility will better enable NWTC engineers and their industry partners to verify the performance and reliability of wind turbine drivetrain prototypes and commercial machines. Increased performance and realiability will lead to more competitively cost wind energy.
The facility will be able to test virtually any land-based turbine in more “real time” conditions that turbines experience out on the “farm”.
“These new capabilities make this a very special facility, one of the largest and finest of its kind in the world,” said NWTC Director Fort Felker. “It gives NREL an enhanced ability to do comprehensive testing of modern multi-megawatt wind turbine systems in a laboratory environment to verify their performance and reliability before they are widely deployed.”
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. Historically, this testing has been done under torque (rotating) loads only. However, the NWTC facility incorporates a non-torque loading system into the testing regimen, a hydraulic device that allows for simulation of both the rotational and bending loads that a wind turbine rotor places on a drivetrain.
“The non-torque loading system is what really sets this facility apart from other comparable test sites,” explained NWTC Dynamometer Project Manager Mark McDade. “This allows us to test the drivetrain system with the types of loads that it will see in a real-world application. It’s a very important feature for a test apparatus because the adverse impacts these types of loads can have on a system are significant.”
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. This provides the rotating loads on the test article. Add to this motorized torque testing the non-torque loading capability unique to the NWTC, and NREL is able to put a wind turbine drivetrain through the most realistic loading tests possible in a laboratory.
“These machines are expected to operate reliably in the field, often in harsh conditions, for 20 years or more,” Felker said. “The ability to comprehensively test these systems in the lab, to verify their reliability and performance before they go into service, is a critically important capability for the wind industry.” Continue reading