Iec 61400-3 dlc 1.4

Wind & Water Controls
1

Dear all,
I have a question please.
For DLC 1.4 according to IEC 61400-3, which is ECD deterministic wind, in “Loads Analysis of a Floating Offshore Wind Turbine Using Fully Coupled Simulation” by J.M. Jonkman and M.L. Buhl, Jr.
the NREL 5 MW turbine was analyzed by FAST and DISCON control, and I read here in this forum that DISCON control doesn’t support shutdown logic. So, DISCON kept the turbine online under extreme yaw misalignments which was 54 deg, and the rotor blades experienced huge deflections which was 14 m.
My question is
I tried to simulate IEA 15 MW with OPENFAST and ROSCO under DLC 1.4 and I had dynamic behavior similar to the mentioned reference. I know that ROSCO also has not been tuned to shutdown under yaw misalignment. So, ROSCO kept the turbine online under extreme yaw misalignments which is in my case 57 deg, and the rotor blades experienced huge deflections which is in my case 35 m! (including PSF of 1.35)
are my results acceptable or I have to change the source code of ROSCO and provide a closed loop response characteristics of the rotor for shutdown and recompile it?

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Regards,
Marwa

2

Hi Marwa,

As of today, you will have to amend the shutdown logic here in ROSCO to detect large yaw misalignments and shut down in those cases.

Best, Dan

1 Like
3

Thanks for your answer, I read in many papers that modern turbines should have the ability to shutdown during large yaw error.
1- is there a reference please that state that to reference that in my thesis, because in IEC 61400-3 , as I remember, didn’t state that.
2- Is there a reference that explain these prameters in the source code to not change them blindly?

Regards,
Marwa

4

Hi Marwa,

I’m not immediately aware of any references. Perhaps you can cite the ones you referred to or the one where Pietro added shutdown logic for that case?

Best, Dan

5

Thanks Daniel for your help.

Regards,
Marwa