Runing DLL files in OpenFast and integrating ROSCO.

[NLGenin21]

Hi, everyone.

I'm new to openFAST and I'm currently researching drive train models and control strategy for my masters thesis.
I want to use OpenFAST as my research tool to analyze the solutions I want to develop and see the operational efficiency and DELs mitigation.

Currently, I'm having a lot of trouble and dificulty to run OpenFAST with ServoDyn file and pitch control mode on number 5 which needs the DLL file.

I'm encountering this issue:

Running ServoDyn Interface for Bladed Controllers (using Intel Visual Fortran for Windows).

FAST_InitializeAll:SrvD_Init:BladedInterface_Init:The procedure
../5MW_Baseline/ServoData/DISCON.dll in file
Simulations/Openfast/NREL-5MW/../5MW_Baseline/ServoData/DISCON.dll could not be loaded.

 OpenFAST encountered an error during module initialization.
 Simulation error level: FATAL ERROR

 Aborting OpenFAST.

I have all 3 DLL files inside the 5MW_Baselin/ServoData folder:

My ServoDyn file is conigured as follows:

"../5MW_Baseline/ServoData/DISCON.dll"  DLL_FileName - Name/location of the dynamic library {.dll [Windows] or .so [Linux]} in the Bladed-DLL format (-) [used only with Bladed Interface]
"../5MW_Baseline/ServoData/DISCON.dll"    DLL_InFile   - Name of input file sent to the DLL (-) [used only with Bladed Interface]
"../5MW_Baseline/ServoData/DISCON.dll"      DLL_ProcName - Name of procedure in DLL to be called (-) [case sensitive; used only with DLL Interface]
"default"     DLL_DT       - Communication interval for dynamic library (s) (or "default") [used only with Bladed Interface]
false         DLL_Ramp     - Whether a linear ramp should be used between DLL_DT time steps [introduces time shift when true] (flag) [used only with Bladed Interface]
     9999.9   BPCutoff     - Cutoff frequency for low-pass filter on blade pitch from DLL (Hz) [used only with Bladed Interface]
          0   NacYaw_North - Reference yaw angle of the nacelle when the upwind end points due North (deg) [used only with Bladed Interface]
          1   Ptch_Cntrl   - Record 28: Use individual pitch control {0: collective pitch; 1: individual pitch control} (switch) [used only with Bladed Interface]
          0   Ptch_SetPnt  - Record  5: Below-rated pitch angle set-point (deg) [used only with Bladed Interface]
          0   Ptch_Min     - Record  6: Minimum pitch angle (deg) [used only with Bladed Interface]
          0   Ptch_Max     - Record  7: Maximum pitch angle (deg) [used only with Bladed Interface]
          0   PtchRate_Min - Record  8: Minimum pitch rate (most negative value allowed) (deg/s) [used only with Bladed Interface]
          0   PtchRate_Max - Record  9: Maximum pitch rate  (deg/s) [used only with Bladed Interface]
          0   Gain_OM      - Record 16: Optimal mode gain (Nm/(rad/s)^2) [used only with Bladed Interface]
          0   GenSpd_MinOM - Record 17: Minimum generator speed (rpm) [used only with Bladed Interface]
          0   GenSpd_MaxOM - Record 18: Optimal mode maximum speed (rpm) [used only with Bladed Interface]
          0   GenSpd_Dem   - Record 19: Demanded generator speed above rated (rpm) [used only with Bladed Interface]
          0   GenTrq_Dem   - Record 22: Demanded generator torque above rated (Nm) [used only with Bladed Interface]
          0   GenPwr_Dem   - Record 13: Demanded power (W) [used only with Bladed Interface]

Could someone help and guide me on how this works?

I also wanted to see if someone has a guide on how to integrate ROSCO with OpenFAST... I'm having a lot of trouble to work with both softwares. I didn't find anything on the internet.

Thanks and Happy New Year to everyone!

[jjonkman]

Dear @NLGenin21,

ServoDyn input DLL_ProcName should be set to the name of the procedure within the DLL that ServoDyn will call. This should be "DISCON", rather than "../5MW_Baseline/ServoData/DISCON.dll", both for the baseline controllers of the NREL 5-MW wind turbine and for ROSCO.

ServoDyn input DLL_InFile does not need to be set to something specific for the baseline controllers of the NREL 5-MW wind turbine because these controllers do not make use of an input file, however, for ROSCO, this should be set to the name of the DISCON input file, e.g., "DISCON.IN".

Best regards,

[NLGenin21]

Dr. Jonkman, what a pleasure to have you answer my question!
I did the changes you mentioned for OpenFAST and it executed correctly. Thank you so much for you help and attention!

Dr.Jonkman, how can I change the parameters of this controller in OpenFAST?

Thanks!

[jjonkman]

Dear @NLGenin21,

For the NREL 5-MW baseline DISCON controllers, the parameters are set within the DISCON.f90 source code. To change these, you'll need to change the parameters in the source code and recompile the DISCON dynamic library.

For the ROSCO controller, to change the parameters, simply change the inputs in the DISCON.IN input file (no recompile necessary).

Best regards,