FAST: Setting a fixed generator torque

Wind & Water Computer-Aided Engineering Software Tools
1

Dear all,

I am currently trying to validate simulations of a simple wind turbine model using FAST as a reference.
It would be of tremendous help if I could tell FAST to hold a specific generator torque while I play with different wind speeds, without any active control algorithms.

Is there a way to do that? I know it is possible to set blade pitch angles to a fixed value. Is there a similar option for the generator torque or do I need to create a specific controller for this purpose?

Thank you!

Peter

2

Dear Peter,

You can easily set a constant generator torque through the simple variable-speed control option (VSContrl = 1) via the following input settings (in the primary FAST input file of FAST v7 or the ServoDyn input file of FAST v8):

VSContrl = 1
VS_RtGnSp = 9999.9E-9
VS_RtTq = the desired constant generator torque in N-m
VS_Rgn2K = 9999.9E-9
VS_SlPc = 9999.9E-9

Please note, though, that if you have a constant generator torque and no other control (such as blade-pitch or nacelle-yaw), the rotor will accelerate or decelerate if the applied aerodynamic torque does not balance with the generator torque.

Best regards,

3

Dear Jason,

thank you for your quick reply!
That strategy had not occured to me.

Best regards,
Peter