Control for scaled-down 5MW NREL

[Jason.Jonkman]

Sounds reasonable to me.

[Saishuai.Dai]

Dear Dr. Jason
Thanks for your suggestion and I have resolved my problem.
Besides, if I can get a measurement of model 6dof motions, how do I replace 6dof motions calculated in fast v8.16 by those?
Could you describe how to do it in detail?


Best Wishes
Jason. Lai

Hi Jason

I am currently trying to do the same as Jason.Lai, in real-time running. I understand that it is not possible to feed the platform into the openfast without customizing the code. I am planning to customize the code so that it can take real-time measured platform motion. Could you please give me some guidance on which part of the code would need to be modified? Any relevant suggestions are appreciated.

Best Regards
Saishuai.Dai

[Jason.Jonkman]

Dear Saishuai,

There are two ways to do this in my mind, as mentioned in the links above.

The first (and likely easiest) method is to increase the platform mass/inertia in ElastoDyn (m), convert the prescribed motion (a) into a prescribed load (F), and calculate the load such that F = ma, which is how Seismic solves the problem (the platform mass/inertia is increased so that the prescribed load (F) dominates other loads applied to the platform, i.e., loads transmitted from the tower, such that the motion (a) will follow what is prescribed). In this case, you could implement the logic for the force (F) in OpenFAST module ExtPtfm

The second approach talks about changing the structural module (ElastoDyn) so that the platform motion in prescribed rather than calculated. This approach would require rearrangement of the equations of motion in ElastoDyn, which is likely a large undertaking.

Best regards,