NREL 550KW gearbox

Hello

Rencently I do some research about drivetrain of wind turbine, I use the Robert G. Parker’s lump-mass model.When I use the parameter of 550KW gearbox to verify the model, I find result of the lump-mass model(2.9Hz,6.19Hz,21.3Hz) is so different from the results(40.75Hz,69.49Hz) given by the NREL.

The lump-mass model is based on
-Analytical Characterization of the Unique Properties of Planetary Gear Free Vibration

The parameter of 550KW gearbox is from the two material
-Dynamic modeling and analysis of a spur planetary gear involving tooth wedging and bearing clearance nonlinearity
-Dynamic Analysis of Wind Turbine Planetary Gears Using an Extended Harmonic Balance Approach

NREL have the 750KW and 1.5MW parameter and the result of natural frequency?

Thank you!

Yin

considering the stiffness Kcr,the results are(Hz)
2.95696265816553
6.19212292560441
41.5581915952016
41.5581915952044
140.757655866164
140.757655866166
258.194918951732
334.122725044914
439.079372827610
439.079372827610

Dear Yin,

What NREL results are you referring to? I’m not familiar with an NREL 550-kW, 750-kW, and 1.5-MW drivetrain.

Best regards,