FAST Pitch Controller with rate limits

Hello,

I was wondering if there was a pitch control subroutine for FAST available that included pitch rate limits.

Thanks,

Hi Scott,

The blade-pitch control system for the NREL 5-MW baseline wind turbine model includes pitch rate limits. You can access the FAST model (i.e., input files), including control system, for the land-based version of the NREL 5-MW turbine from http://wind.nrel.gov/public/jjonkman/NRELOffshrBsline5MW/. The contents of the archive are as follows:

38060.pdf - PDF that documents the properties of the baseline wind turbine model, including a description of the aerodynamic, structural, and control features. The document also describes much of the rationale behind the properties. This the draft version of the (hopefully) soon-to-be-released “official” NREL publication. Before it becomes official, you can reference the NREL 5-MW model as follows: “Jonkman, J.; Butterfield, S.; Musial, W.; and Scott, G., “Definition of a 5-MW Reference Wind Turbine for Offshore System Development,” NREL/TP-500-38060, Golden, CO: National Renewable Energy Laboratory, April 2008 (to be published).”

NRELOffshrBsline5MW_Onshore.fst – Primary FAST input file for the NREL 5-MW baseline wind turbine mounted on land.

NRELOffshrBsline5MW_*.dat & .ipt Files – Additional FAST input files pertaining to the blades, tower (in its land-based configuration), linearization, FAST-to-ADAMS preprocessor, and AeroDyn.

AeroData/*.dat Files – Data files that contain numerical values for all of the airfoil coefficients, including lift (Cl), drag (Cd), and pitching moment (Cm) as a function of angle-of-attack (alpha).

DISCON.dll – DLL containing the variable-speed generator torque and blade-pitch controller as implemented in GH Bladed-style.

DISCON.f90 – Source code for the DLL controller.

As you can see, the torque and pitch control system for this turbine is implemented as a DLL in the style of GH Bladed. If you want to run the model with this controller, you will have to recompile FAST using the BladedDLLInterface.f90 source file. The DLL source code includes logic for implementing pitch rate limits, if that is all you need.

Best regards,

Jason,

Thank you for directing me to this information.

Regards,

Is there a wind file for this 5MW code? I hastily used one from my own experiments with a 15 m/s wind speed. I’m getting errors about violation of small angle assumptions and simulation terminates with an overflow error.

WARNING:
Small angle assumption violated in SUBROUTINE SmllRotTrans() due to a large blade deflection. The solution may be in accurate.

This was followed by

Program warning in Subroutine VINDERR.
High VNB velocity encountered during induction factor calculation.

Thanks!
~Orion

Hi- I’ve been able to run the 5 MW model with a file I use for pitch control evaluation- listed below. It dwells for a while at 15 m/s.

! Hub-height AeroDyn wind file for pitch control test
! Time Wind Wind Vert. Horiz. Vert. LinV Gust
! Speed Dir Speed Shear Shear Shear Speed
0 10 0 0 0 0 0 0
29 10 0 0 0 0 0 0
30 11 0 0 0 0 0 0
59 11 0 0 0 0 0 0
60 12 0 0 0 0 0 0
89 12 0 0 0 0 0 0
90 12.2 0 0 0 0 0 0
91 12.4 0 0 0 0 0 0
92 12.6 0 0 0 0 0 0
93 12.8 0 0 0 0 0 0
94 13 0 0 0 0 0 0
95 13.2 0 0 0 0 0 0
96 13.4 0 0 0 0 0 0
97 13.6 0 0 0 0 0 0
98 13.8 0 0 0 0 0 0
99 14 0 0 0 0 0 0
128 14 0 0 0 0 0 0
129 15 0 0 0 0 0 0
158 15 0 0 0 0 0 0
159 15.2 0 0 0 0 0 0
160 15.4 0 0 0 0 0 0
161 15.6 0 0 0 0 0 0
162 15.8 0 0 0 0 0 0
163 16 0 0 0 0 0 0
164 16.2 0 0 0 0 0 0
165 16.4 0 0 0 0 0 0
166 16.6 0 0 0 0 0 0
167 16.8 0 0 0 0 0 0
168 17 0 0 0 0 0 0
169 17.2 0 0 0 0 0 0
170 17.4 0 0 0 0 0 0
171 17.6 0 0 0 0 0 0
172 17.8 0 0 0 0 0 0
173 18 0 0 0 0 0 0
174 18.2 0 0 0 0 0 0
175 18.4 0 0 0 0 0 0
176 18.6 0 0 0 0 0 0
177 18.8 0 0 0 0 0 0
178 19 0 0 0 0 0 0
179 19.2 0 0 0 0 0 0
180 19.4 0 0 0 0 0 0
181 19.6 0 0 0 0 0 0
182 19.8 0 0 0 0 0 0
183 20 0 0 0 0 0 0
212 20 0 0 0 0 0 0
213 21 0 0 0 0 0 0
245 21 0 0 0 0 0 0

Thanks Scott,

Turns out I had left the GBRatio in a bad state after testing a different condition. I’m just beginning with FAST so thanks for patience with my novice questions. :unamused:

Does anyone have this file available? When I set VSContrl in the .fst input file to 2, UserVSCont_KP.f90 tries to read spd_trq.dat. When I change VSContrl to 1, the simulation runs fine. Which is actually ok as long as I can confirm I’m still running with the variable pitch control from the DISCON.dll. (What does DISCON stand for?).

I thought with PCMode set to 1 for user-defined from PtchCntrl, I would see displayed the cMessage:
'Running with torque and pitch control of the NREL offshore '// &
'5MW baseline wind turbine from DISCON.dll as written by J. '// &
'Jonkman of NREL/NWTC for use in the IEA Annex XXIII OC3 ’ // &
‘studies.’

But I don’t see it. Can anyone confirm. Many thanks.

Dear Orion,

The file spd_trq.dat is a data file that is read in from Kirk Pierce’s UserVSCont() routine that is found in UserVSCont_KP.f90. There is a sample spd_trq.dat file found in FAST’s CertTest folder. UserVSCont_KP.f90 is compiled in with the standard FAST executable that is found in the standard FAST archive. The standard FAST executable doesn’t come compiled with the GH Bladed-style DISCON.dll interface (DISCON standards for DIScrete CONtroller in GH Bladed).

The message you copied into your e-mail is displayed when your run FAST with the DISCON.dll for the NREL 5-MW baseline wind turbine model. If it is not displayed by FAST, you are not running this DISCON.dll. From your post, though, it sounds like you are running the standerd version of FAST without the DLL interface. See the “Compiling FAST” chapter of the FAST User’s Guide for instructions on how to recompile FAST with the DLL interface.

Best regards,