Laboratory Testing of Drivetrain Component Efficiencues for Constant-Speed and Variable-Speed Wind Turbines. November 4, 1997-November 3, 2000

摘要

In 1993, the National Renewable Energy Laboratory (NREL) awarded Electronic Power Conditioning, Inc., (EPC) a subcontract under which EPC designed, built and tested variablespeed generator systems (VSGS) as retrofits for two different existing fixed-speed turbine designs. The VSGS were tested in the laboratory and in the field. One of the VSGS designs was for the Advanced Wind Turbines, Inc., (AWT) model AWT-26 wind turbine. That design was tested at the National Wind Technology Center (NWTC) test site on an AWT-26 prototype known as P3. To support this design and testing program, EPC and AWT carried out laboratory tests of drivetrain component efficiencies. The AWT gearbox tests involved three different models of Flender PZBS-170 (two-stage, planetary) gearboxes. The test results showed that the gearbox power losses resulted mainly from oil churning, depended strongly on oil temperature, increased rapidly with shaft rotation speed, and increased weakly with gearbox load. At a given (low-speed shaft) rotational speed, the power losses were found to be independent of both gearing ratio and rotation direction. EPC laboratory testing included both the original P3 induction generator at fixed speed, and the doubly-fed generator / power converter VSGS system that EPC designed for variable-speed operation of P3. The fixed-speed induction generator had higher efficiency than the VSGS at all power levels.