Pitch control NREL 5MW wind trubine

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Malte.Frieling
Posts: 7
Joined: Tue Apr 21, 2020 2:06 am
Organization: Universität Bremen
Location: Germany

Pitch control NREL 5MW wind trubine

Postby Malte.Frieling » Wed May 13, 2020 10:34 am

Hello everybody,

I have a problem with the pitch controller of the NREL 5MW wind turbine. On the NREL 5 MW reference wind turbine I simulate 6 seeds with wind speeds from 3 to 25 m*s^-1 with the initial conditions from the document "Definition of a 5 MW Reference Wind Turbine for Offshore System Development". Most simulations run without problems, but it comes at 4 simulations to problems with the pitch controller. The 4 simulations are for seed 2 with 15 m*s^-1, for seed 3 with 13 and 15 m*s^-1 and for seed 5 with 17 m*s^-1. The pitch controller swings at some point with a pitch angle between 0 and 90 degrees (see picture). All simulations are carried out without hydrodynamic loads. The initial conditions for the wind speeds 13, 15 and 17 m*s^-1 are listed below:

Initia_Conditions.PNG
Initia_Conditions.PNG (5.13 KiB) Viewed 198 times

Seed2_15mps.jpg
Seed2_15mps.jpg (144.33 KiB) Viewed 198 times


Best regards,

Malte Frieling

Jason.Jonkman
Posts: 4777
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
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Re: Pitch control NREL 5MW wind trubine

Postby Jason.Jonkman » Wed May 13, 2020 3:09 pm

Dear Malte,

Your initial conditions look OK to me. I'm not sure what the problem is.

Do all simulations fail at the same time (at about 3400 s)? What aerodynamic features have you enabled in AeroDyn?

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Malte.Frieling
Posts: 7
Joined: Tue Apr 21, 2020 2:06 am
Organization: Universität Bremen
Location: Germany

Re: Pitch control NREL 5MW wind trubine

Postby Malte.Frieling » Mon May 18, 2020 1:26 am

Hi Dr. Jonkman,

all four simulations fail at different times (seed 2 15mps approximately at 3400s, seed 3 13mps approximately at 2500s, seed 3 15mps approximately at 2100s and seed 5 17mps approximately at 2400s).

AeroDyn code:

Code: Select all

------- AERODYN v15 for OpenFAST INPUT FILE -----------------------------------------------
NREL 5.0 MW offshore baseline aerodynamic input properties, with OC3 Monopile tower
======  General Options  ============================================================================
False         Echo               - Echo the input to "<rootname>.AD.ech"?  (flag)
"default"     DTAero             - Time interval for aerodynamic calculations {or "default"} (s)
          1   WakeMod            - Type of wake/induction model (switch) {0=none, 1=BEMT, 2=DBEMT} [WakeMod cannot be 2 when linearizing]
          2   AFAeroMod          - Type of blade airfoil aerodynamics model (switch) {1=steady model, 2=Beddoes-Leishman unsteady model} [AFAeroMod must be 1 when linearizing]
          1   TwrPotent          - Type tower influence on wind based on potential flow around the tower (switch) {0=none, 1=baseline potential flow, 2=potential flow with Bak correction}
False         TwrShadow          - Calculate tower influence on wind based on downstream tower shadow? (flag)
True          TwrAero            - Calculate tower aerodynamic loads? (flag)
False         FrozenWake         - Assume frozen wake during linearization? (flag) [used only when WakeMod=1 and when linearizing]
False         CavitCheck         - Perform cavitation check? (flag) [AFAeroMod must be 1 when CavitCheck=true]
======  Environmental Conditions  ===================================================================
      1.225   AirDens            - Air density (kg/m^3)
  1.464E-05   KinVisc            - Kinematic air viscosity (m^2/s)
        335   SpdSound           - Speed of sound (m/s)
     103500   Patm               - Atmospheric pressure (Pa) [used only when CavitCheck=True]
       1700   Pvap               - Vapour pressure of fluid (Pa) [used only when CavitCheck=True]
        0.5   FluidDepth         - Water depth above mid-hub height (m) [used only when CavitCheck=True]
======  Blade-Element/Momentum Theory Options  ====================================================== [unused when WakeMod=0]
          2   SkewMod            - Type of skewed-wake correction model (switch) {1=uncoupled, 2=Pitt/Peters, 3=coupled} [unused when WakeMod=0]
"default"     SkewModFactor      - Constant used in Pitt/Peters skewed wake model {or "default" is 15/32*pi} (-) [used only when SkewMod=2; unused when WakeMod=0]
True          TipLoss            - Use the Prandtl tip-loss model? (flag) [unused when WakeMod=0]
True          HubLoss            - Use the Prandtl hub-loss model? (flag) [unused when WakeMod=0]
true          TanInd             - Include tangential induction in BEMT calculations? (flag) [unused when WakeMod=0]
False         AIDrag             - Include the drag term in the axial-induction calculation? (flag) [unused when WakeMod=0]
False         TIDrag             - Include the drag term in the tangential-induction calculation? (flag) [unused when WakeMod=0 or TanInd=FALSE]
"Default"     IndToler           - Convergence tolerance for BEMT nonlinear solve residual equation {or "default"} (-) [unused when WakeMod=0]
        100   MaxIter            - Maximum number of iteration steps (-) [unused when WakeMod=0]
======  Dynamic Blade-Element/Momentum Theory Options  ============================================== [used only when WakeMod=2]
          2   DBEMT_Mod          - Type of dynamic BEMT (DBEMT) model {1=constant tau1, 2=time-dependent tau1} (-) [used only when WakeMod=2]
          4   tau1_const         - Time constant for DBEMT (s) [used only when WakeMod=2 and DBEMT_Mod=1]
======  Beddoes-Leishman Unsteady Airfoil Aerodynamics Options  ===================================== [used only when AFAeroMod=2]
          3   UAMod              - Unsteady Aero Model Switch (switch) {1=Baseline model (Original), 2=Gonzalez's variant (changes in Cn,Cc,Cm), 3=Minemma/Pierce variant (changes in Cc and Cm)} [used only when AFAeroMod=2]
True          FLookup            - Flag to indicate whether a lookup for f' will be calculated (TRUE) or whether best-fit exponential equations will be used (FALSE); if FALSE S1-S4 must be provided in airfoil input files (flag) [used only when AFAeroMod=2]
======  Airfoil Information =========================================================================
          1   InCol_Alfa         - The column in the airfoil tables that contains the angle of attack (-)
          2   InCol_Cl           - The column in the airfoil tables that contains the lift coefficient (-)
          3   InCol_Cd           - The column in the airfoil tables that contains the drag coefficient (-)
          4   InCol_Cm           - The column in the airfoil tables that contains the pitching-moment coefficient; use zero if there is no Cm column (-)
          0   InCol_Cpmin        - The column in the airfoil tables that contains the Cpmin coefficient; use zero if there is no Cpmin column (-)
          8   NumAFfiles         - Number of airfoil files used (-)
"Airfoils/Cylinder1.dat"    AFNames            - Airfoil file names (NumAFfiles lines) (quoted strings)
"Airfoils/Cylinder2.dat"
"Airfoils/DU40_A17.dat"
"Airfoils/DU35_A17.dat"
"Airfoils/DU30_A17.dat"
"Airfoils/DU25_A17.dat"
"Airfoils/DU21_A17.dat"
"Airfoils/NACA64_A17.dat"
======  Rotor/Blade Properties  =====================================================================
True          UseBlCm            - Include aerodynamic pitching moment in calculations?  (flag)
"NRELOffshrBsline5MW_AeroDyn_blade.dat"    ADBlFile(1)        - Name of file containing distributed aerodynamic properties for Blade #1 (-)
"NRELOffshrBsline5MW_AeroDyn_blade.dat"    ADBlFile(2)        - Name of file containing distributed aerodynamic properties for Blade #2 (-) [unused if NumBl < 2]
"NRELOffshrBsline5MW_AeroDyn_blade.dat"    ADBlFile(3)        - Name of file containing distributed aerodynamic properties for Blade #3 (-) [unused if NumBl < 3]
======  Tower Influence and Aerodynamics ============================================================= [used only when TwrPotent/=0, TwrShadow=True, or TwrAero=True]
         11   NumTwrNds         - Number of tower nodes used in the analysis  (-) [used only when TwrPotent/=0, TwrShadow=True, or TwrAero=True]
TwrElev        TwrDiam        TwrCd
(m)              (m)           (-)
1.0000000E+01  6.0000000E+00  1.0000000E+00 
1.7760000E+01  5.7870000E+00  1.0000000E+00 
2.5520000E+01  5.5740000E+00  1.0000000E+00 
3.3280000E+01  5.3610000E+00  1.0000000E+00 
4.1040000E+01  5.1480000E+00  1.0000000E+00 
4.8800000E+01  4.9350000E+00  1.0000000E+00 
5.6560000E+01  4.7220000E+00  1.0000000E+00 
6.4320000E+01  4.5090000E+00  1.0000000E+00 
7.2080000E+01  4.2960000E+00  1.0000000E+00 
7.9840000E+01  4.0830000E+00  1.0000000E+00 
8.7600000E+01  3.8700000E+00  1.0000000E+00 
======  Outputs  ====================================================================================
Flase          SumPrint            - Generate a summary file listing input options and interpolated properties to "<rootname>.AD.sum"?  (flag)
          0   NBlOuts             - Number of blade node outputs [0 - 9] (-)
          2,          9,         16,          4,          5,          7,         11,         13,         14    BlOutNd             - Blade nodes whose values will be output  (-)
          0   NTwOuts             - Number of tower node outputs [0 - 9]  (-)
          1,          2,          3,          4,          5    TwOutNd             - Tower nodes whose values will be output  (-)
                   OutList             - The next line(s) contains a list of output parameters.  See OutListParameters.xlsx for a listing of available output channels, (-)
"B1Pitch"
"B2Pitch"
"B3Pitch"
"RtSpeed"
END of input file (the word "END" must appear in the first 3 columns of this last OutList line)
---------------------------------------------------------------------------------------


Best regards,

Malte Frieling

Jason.Jonkman
Posts: 4777
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: Pitch control NREL 5MW wind trubine

Postby Jason.Jonkman » Mon May 18, 2020 7:17 am

Dear Malte,

I'm not sure what would cause this; your AeroDyn v15 input file looks fine with me. And all failures happen late into the simulation at different times, which makes it difficult to debug.

Which version of FAST/OpenFAST are you running? Did you compile yourself?

As a stop gap, it may be easiest to simply run the 4 simulations that result in controller issues with different seeds, but it would be nice to know why this is happening. We've run the NREL 5-MW turbine model with baseline controller for many, many simulations, and I would not expect this to happen.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Malte.Frieling
Posts: 7
Joined: Tue Apr 21, 2020 2:06 am
Organization: Universität Bremen
Location: Germany

Re: Pitch control NREL 5MW wind trubine

Postby Malte.Frieling » Wed May 20, 2020 12:36 pm

Hello Dr. Jonkman,

At following picture I also plotted rotor speed. At the time the pitch control fails the rotor speed reaches a maximum of 13.97 rpm. Could it be related to that?

Best regards,

Malte.
Attachments
Seed2_15mps_2.jpg
Seed2_15mps_2.jpg (194.91 KiB) Viewed 153 times

Jason.Jonkman
Posts: 4777
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: Pitch control NREL 5MW wind trubine

Postby Jason.Jonkman » Wed May 20, 2020 1:30 pm

Dear Malte,

I'm not aware of anything in the NREL 5-MW baseline controller that would cause problems at high rotor-speed error.

Again, which version of FAST/OpenFAST are you running? Did you compile yourself?

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Malte.Frieling
Posts: 7
Joined: Tue Apr 21, 2020 2:06 am
Organization: Universität Bremen
Location: Germany

Re: Pitch control NREL 5MW wind trubine

Postby Malte.Frieling » Fri May 22, 2020 9:41 am

Hi Dr.Jonkman,

sorry i forgot to answer about the version.
I use OpenFAST v2.2.0.

Best regards,

Malte

Jason.Jonkman
Posts: 4777
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: Pitch control NREL 5MW wind trubine

Postby Jason.Jonkman » Fri May 22, 2020 10:28 am

Dear Malte,

Did you compile OpenFAST v.2.2 or the controller DLL yourself?

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov


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