Problem running Test18.fst in Simulink by Changing TMax using FAST_8.16

hello,

I use FAST_8.16 to simulate Test18.fst (Onshore) in Simulink and I want to change TMax.
I want to simulate test18 in simulink with a different Tmax (e.g., TMax = 630). If I change TMax in Input file Test18.fst, I get the following errors.

An error occurred while running the simulation and the simulation was terminated

Error reported by S-function ‘FAST_SFunc’ in ‘Test18/FAST Nonlinear Wind Turbine/S-Function’:
FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:InflowWind_CalcOutput:CalcOutput:IfW_TSFFWind_CalcOutput [position=(-8.5233, 22.253, 51.685) in wind-file coordinates]: Error: FF wind array was exhausted at 65.35 seconds (trying to access data at 72.102 seconds).

How can I change TMax?.
And Does anyone have any documentations about the Implementation of Individual pitch control?

Thank you

Dear David,

This error is triggered because you are trying to run a simulation longer than you have turbulent wind data input for. Before running a simulation with turbulent wind, you must first use TurbSim to generate a wind data input file that is at least as long as the simulation you want to run.

Individual pitch control is quite common, so, there are many publications available on it.

Best regards,

Dear Jason,

thank you for your answer. Please I have another problem. I try to simulate my modell in simulink and I become this error:

An error occurred while running the simulation and the simulation was terminated

Error reported by S-function ‘FAST_SFunc’ in ‘OpenLoop18/FAST Nonlinear Wind Turbine/S-Function’:
FAST_Solution:FAST_AdvanceStates:AD_UpdateStates:BEMT_UpdateStates(node 10, blade 2):BEMT_UnCoupledSolve:DeterminePhiBounds:There is no valid value of phi for these operating conditions! Vx = -5.9531, Vy = 264.19, rlocal = 32.187, theta = 0.4189

Please do you have some Idea?

Dear David,

We are aware of a problem with the BEMT algorithm in AeroDyn v15.00 – v15.03 that manifests itself when Vx goes negative (common under operational conditions with low mean wind speed and high turbulence) – see the following forum post for a discussion on this and updated source code that addresses this issue: http://forums.nrel.gov/t/fast-v8-aerodyn-v15-convergence-problems-for-low-speed-high-turbulence/1532/2. In your case, however, I question whether your simulation is set-up correctly as the Vx reported in your error is well below zero and Vy is very large.

Best regards,

Dear Jason,

thank you for your repply. Please, how can I create a simple wind ramp starting at the cut-in wind speed positive step changes of (e.g. 0.5m/s) every (e.g 15) seconds until the cut-out wind speed?. Or please Do you have an example that I can use for my simulation?
Thanks in advance

Greeting David

Dear David,

A similar question has been asked and answered in the following forum topic: http://forums.nrel.gov/t/step-wind-change-input/1360/2.

Best regards,

Hell Dear jason,

I’m having problem by creating the uniform Windfile.
I use the example from InFloWind folder. I have changed the sample Test002 uniform. I use a .hh file as a steptime-wind ( 0.5m/s) every (e.g 15) ).
Finally, I have the following files: .ech., .out, ipt, .dvr.

Which file can I use in NRELOffshrBsline5MW_InflowWind_12mps for Winttype for FAST_v8?

Best regards,

Dear David,

I’m not sure I really understand your question, but the .hh file you adapted is the file you should specify via input Filename in the uniform wind file parameters section of the InflowWind input file for WindType=2.

Best regards,

Hello Dear Jason,

Thank you for your quick response and your help. Please, is it possible to create a Stochastic Turbulent Wind Field?. For exmaple I want to create a turbulence wind speeds in three categories: above rated, rated, and below rated.

I have no idea how I can set this in the TurbSim-file to get that. Do you have an idea how I could do that?

Thank you in advance.

Bests regards,

Dear David,

Yes, TurbSim should be used to generate turbulent wind data for use in FAST. Please see the May 17, 2010 post in the forum topic linked here for an example TurbSim input file we’ve used for the NREL 5-MW baseline turbine: http://forums.nrel.gov/t/updated-nwtc-design-codes-available-on-our-web-site/237/1.

Best regards,

Hallo Dear Jason,

Please, I have a question. In “Definition of a 5-MW Reference Wind Turbine for Offshore” the plots are depending on wind Speed (x-axis).
Wenn I use a constant wind speed for WindType = 1 or wind step for WindType = 2 , my plots are depending on time.

But I would like to plot in dependent on wind speed as in the figure 9.1 in “Definition of a 5-MW Reference Wind Turbine for Offshore”
Please,Can you tell me how to get my plots in depending on wind as in Figure 9.1? Or what can I set in FAST Inpule file?

thank you in advance

Dear David,

As described in the NREL 5-MW specifications report, we generated the results of Figure 9-1 by running a series of FAST simulations at a number of given, steady, and uniform wind speeds (WindType = 1). Separate simulations were run at each wind speed and each simulation was run long enough to ensure that all transient behavior had died out. We recorded the steady-state output values from each simulation and plotted them as a line in Figure 9-1 (thus, only the steady-state response is shown).

I hope that helps.

Best regards,

Hallo Jason,

Thank you for your feedback. I’m trying to do it.

Best regards,

Hallo Jason,

I have compare my simulink results with FAST-DLL . I have “WindType = 1” with a wind speed of “12m / s”. These are single plots: Pitchangle, RotorSpeed ​​and GenPower for example.

For FAST-DELL I set in ServoDyn only: “PCMode = 5” , “VSContrl = 5” and “PitManRat = 8”.
Is it right? Or should I use " SIMPLE VARIABLE-SPEED TORQUE CONTROL" for DLL-Simulation?

For my Simulink Modell: “PCMode = 4” , “VSContrl = 4”

RotSpeed.pngPitchangle.png

I hope my plots are correct?.

Please how can I set the FAST Input file wenn I want to implement Individual Pitch Controller?

Best regards,

Dear David,

I’m not sure I really understand your question. I can’t tell you what options to use as this depends on what you want to do.

It looks like you are trying to mimic the NREL 5-MW baseline control logic that is implemented in the NREL-provided DLL with a Simulink implementation? Your Simulink results look close, but not exact to those from the DLL.

There is nothing to change in the FAST input files to set-up individual pitch control; instead, you must set up a pitch controller for your own purposes.

Best regards,

Hallo Jason,

I want to inplement Indiviual Pitch Controller for “Test18.fst” in Simulink.

First, I have tried with the help of " Flowchart of the baseline control system" from Figure 7-5 in Document Reference 5MW a collective Pitch Controller and Generator Torque Controller using Simulink to implement and compare the results with FAST-DLL results. The pictures from above were some results.

I was not sure because I did not use the “SIMPLE VARIABLE-SPEED TORQUE CONTROL” to modell, but I tried to interpret the FAST DLL in simulink.

Are my procedures correct? Or is there another method to do this?

Best regards,

Dear David,

As far as I understand what you’re saying, your approach sounds correct. Your Simulink results look close, but not exact to those from the DLL, so, I expect some differences between the two implementations

Best regards,

Hallo Dear Jason,

Tkank you for your answer.

Please, what kind of differences between the two implementations do you expect?

Best regards,

Dear David,

I don’t know anything about your implementation, so, I can’t guess as to what the differences may be.

Best regards,

Hallo Dear Jason,

I want to implement in Simulink Idividual Pitch Controller for Test.18. But I have doubts about the parameters.

for Collective Pitch Controller I used:
“BldPitch1” - Blade 1 pitch angle

and for Individaul Pitch Controller, I take from OutListParameters…xlsx and put them in …Onshore_ElastoDyn file
“BlPitch1” - Blade 1 pitch angle
“BlPitch2” - Blade 2 pitch angle
“BlPitch3” - Blade 3 pitch angle

I use following paramters for the Coleman transformation
“RootMxb1” - In-plane bending, out-of-plane bending, and pitching moments at the root of blade 1
“RootMyb1” - In-plane bending, out-of-plane bending, and pitching moments at the root of blade 1
“RootMzb1” - In-plane bending, out-of-plane bending, and pitching moments at the root of blade 1

Are these parameters correct for the Individual Pitch Controller?
Can I use the same PID as the PID Collective Pitch for the Individual Pitch Controller?

Thank you in advance,

Bests regards,