Thanks for your activating my account and quick reply.

I am running Fast to create a periodic linearized model. My aim of the analysis is to get State space matrices : A,B,C,D such that i can compared with my own model of wind turbine.

i am taking all the parameters of:
Test13: WP 1.5 MW, 3blade, 70m diameter , 1500KW Flexible, variable speed & pitch control, turbulence

I set AnalMode to 2 in Test13.fst. Also changed the parameters in linearisation file :Baseline_Linear.dat in accordance to the Fast manual.

I changed the current directory to CertTest directory and copied the simulink folder files and wind files CertTest folder.

Then by giving folowing commands in Matlab command prompt, i get following errors:

Simsetup

Enter the name of the FAST input file to read

< Test13.fst
FAST certification Test #13: WindPACT 1.5 MW Baseline with many DOFs with VS and VP and FF turbulence.

then i opened openloop.mdl and run the simulation
then in command prompt, i get following error.

Running FAST (v7.00.00a-bjj, 31-Mar-2010)-Compiled as S-Function for Simulink.
Linked with NWTC Subroutine Library (v1.02.00, 16-Mar-2010).

Heading of the FAST input file: FAST certification Test #13: WindPACT 1.5 MW Baseline with many
DOFs with VS and VP and FF turbulence.
FAST can’t linearize the model when interfaced with Simulink. Set AnalMode to 1 or use the
standard version of FAST.

Aborting FAST.

While running simulation,I also get following error in pop up box:

Error while obtaining sizes from MEX S-function ‘FAST_SFunc’ in ‘OpenLoop/FAST Nonlinear Wind Turbine/S-Function’. MATLAB error message:
Closing program.

As here file more than 2Mb cant be uploaded i uploaded it on other site;
you can download Fast archive from

I’ve already answered this question through our e-mail exchange, but I’ll copy the answer here for others who are following this post.

The linearization functionality of FAST is not available in the S-Function for Simulink. You must use the FAST executable to use the linearization feature. This is stated in the MATLAB command window error message:

With your great help i am able to run Fast and got the results also. thanks a lot.

I also used MBC3 to calculate eigenvalues, natural frequencies and etc. But if i want to know which natural frequency corresponds to which degree of freedom activated, then how i will get to know this from MBC3 or any other subroutine. Is there any command for this specific thing.
please help me out of this new thing.

You must compare the eigenvalues with the eigenvectors to see which frequency corresponds to which mode (the largest components of the eigenvectors represent the dominant components of each mode). I’ve created an MS Excel workbook titled “CampbellDiagram.xls” to aid in analyzing the eigenvalues and eigenvectors from MBC3. This workbook is attached. Please note that you never “need” to use this spreadsheet–it is simply a tool to aid in the inspection of the eigensolution. I hope you find it useful. The process is as follows:

Once a .lin file has been generated by FAST, run the MBC3 GetMats.m and mbc3.m MATLAB scripts.
Open up CampbellDiagram.xls and transfer the data (copy/paste) from the MBC3 output to the gray cells with notes. See the instructions in the workbook.

The CampbellDiagram.xls workbook sorts the eigenvalues and eigenvectors by frequency and highlights the dominant components of each mode. This should aid in interpreting the modes correctly. You can add worksheets for each rotational speed you’ve analyzed. The first worksheet can be used to plot the frequencies or damping as a function of rotational speed; however, this is not done automatically–it is up to you to manually identify the modes. Otherwise, the workbook is fairly self-explanatory.

Please note that the state descriptions (DescStates array) are not presently transformed from FAST’s conventional to MBC3 convention by MBC3 v1.00.00a-gbir. The following convention is used:

I’ve asked Gunjit Bir, the author of MBC3, to have mbc3.m output the MBC state descriptions accordingly. So, this should become available in the next release of MBC3.

Problem in inputing constant wind speed: My aim is to extract the linearised matrices of wind turbine at 14m/sec constant wind speed. As you have replied to my mail earlier:

I am using steady wind file as provided with aerodyn( wind speed changed), but when i run linearisation , i get following error:

I am sending Steady wind file through mail . How to get away with this error?

problem in workbook :: Here i am extracting state space linearised matrices A,B,C,D with wind speed 0. As written in workbook help, i am coping and pasting the results into grey cells according to instructions, but no cell is turning to green and bold red.I have copied the output to workbook .I sent you workbook,test14.lin and steady wind file through mail. Please let me know whats the mistake i am committing.

The error message you received indicates that the wind file you specified did not have an extension, so, AeroDyn assumed that it was a full-field file. With hub-height files, you must give AeroDyn the name of the file, including extension. In your e-mail, you attached hub-height file named, “Steady.wnd.” Make sure to include the “.wnd” extension when you enter this file name in the AeroDyn input file.

In your e-mail’s attached spreadsheet, the data was pasted in as text instead of data that fills the cells. I used the “Text to Columns” feature of MS Excel to include the data correctly. The updated spreadsheet is attached.

First of all I would like to thank you for solving my lots of relevant and irrelevant problems in FAST(sorry for irrelevant doubts). Thankx a lot .
I will give a one more trouble this time…
First i am writing Input files which i have used during linearisation analysis. Then i will state the problem.

fast input file used :

--------------------------------------------------------------------------------
------- FAST INPUT FILE --------------------------------------------------------
FAST certification Test #14: WindPACT 1.5 MW Baseline with many DOFs and system linearization.
Model properties from "InputData1.5A08V07adm.xls" (from C. Hansen) with bugs removed. Compatible with FAST v7.00.00.
---------------------- SIMULATION CONTROL --------------------------------------
False Echo - Echo input data to "echo.out" (flag)
1 ADAMSPrep - ADAMS preprocessor mode {1: Run FAST, 2: use FAST as a preprocessor to create an ADAMS model, 3: do both} (switch)
2 AnalMode - Analysis mode {1: Run a time-marching simulation, 2: create a periodic linearized model} (switch)
3 NumBl - Number of blades (-)
500.0 TMax - Total run time (s)
0.005 DT - Integration time step (s)
---------------------- TURBINE CONTROL -----------------------------------------
0 YCMode - Yaw control mode {0: none, 1: user-defined from routine UserYawCont, 2: user-defined from Simulink} (switch)
9999.9 TYCOn - Time to enable active yaw control (s) [unused when YCMode=0]
0 PCMode - Pitch control mode {0: none, 1: user-defined from routine PitchCntrl, 2: user-defined from Simulink} (switch)
9999.9 TPCOn - Time to enable active pitch control (s) [unused when PCMode=0]
1 VSContrl - Variable-speed control mode {0: none, 1: simple VS, 2: user-defined from routine UserVSCont, 3: user-defined from Simulink} (switch)
1800.0 VS_RtGnSp - Rated generator speed for simple variable-speed generator control (HSS side) (rpm) [used only when VSContrl=1]
8376.58 VS_RtTq - Rated generator torque/constant generator torque in Region 3 for simple variable-speed generator control (HSS side) (N-m) [used only when VSContrl=1]
0.002585 VS_Rgn2K - Generator torque constant in Region 2 for simple variable-speed generator control (HSS side) (N-m/rpm^2) [used only when VSContrl=1]
9999.9E-9 VS_SlPc - Rated generator slip percentage in Region 2 1/2 for simple variable-speed generator control (%) [used only when VSContrl=1]
1 GenModel - Generator model {1: simple, 2: Thevenin, 3: user-defined from routine UserGen} (switch) [used only when VSContrl=0]
True GenTiStr - Method to start the generator {T: timed using TimGenOn, F: generator speed using SpdGenOn} (flag)
True GenTiStp - Method to stop the generator {T: timed using TimGenOf, F: when generator power = 0} (flag)
9999.9 SpdGenOn - Generator speed to turn on the generator for a startup (HSS speed) (rpm) [used only when GenTiStr=False]
0.0 TimGenOn - Time to turn on the generator for a startup (s) [used only when GenTiStr=True]
9999.9 TimGenOf - Time to turn off the generator (s) [used only when GenTiStp=True]
1 HSSBrMode - HSS brake model {1: simple, 2: user-defined from routine UserHSSBr} (switch)
9999.9 THSSBrDp - Time to initiate deployment of the HSS brake (s)
9999.9 TiDynBrk - Time to initiate deployment of the dynamic generator brake [CURRENTLY IGNORED] (s)
9999.9 TTpBrDp(1) - Time to initiate deployment of tip brake 1 (s)
9999.9 TTpBrDp(2) - Time to initiate deployment of tip brake 2 (s)
9999.9 TTpBrDp(3) - Time to initiate deployment of tip brake 3 (s) [unused for 2 blades]
9999.9 TBDepISp(1) - Deployment-initiation speed for the tip brake on blade 1 (rpm)
9999.9 TBDepISp(2) - Deployment-initiation speed for the tip brake on blade 2 (rpm)
9999.9 TBDepISp(3) - Deployment-initiation speed for the tip brake on blade 3 (rpm) [unused for 2 blades]
9999.9 TYawManS - Time to start override yaw maneuver and end standard yaw control (s)
9999.9 TYawManE - Time at which override yaw maneuver reaches final yaw angle (s)
0.0 NacYawF - Final yaw angle for yaw maneuvers (degrees)
9999.9 TPitManS(1) - Time to start override pitch maneuver for blade 1 and end standard pitch control (s)
9999.9 TPitManS(2) - Time to start override pitch maneuver for blade 2 and end standard pitch control (s)
9999.9 TPitManS(3) - Time to start override pitch maneuver for blade 3 and end standard pitch control (s) [unused for 2 blades]
9999.9 TPitManE(1) - Time at which override pitch maneuver for blade 1 reaches final pitch (s)
9999.9 TPitManE(2) - Time at which override pitch maneuver for blade 2 reaches final pitch (s)
9999.9 TPitManE(3) - Time at which override pitch maneuver for blade 3 reaches final pitch (s) [unused for 2 blades]
4 BlPitch(1) - Blade 1 initial pitch (degrees)
4 BlPitch(2) - Blade 2 initial pitch (degrees)
4 BlPitch(3) - Blade 3 initial pitch (degrees) [unused for 2 blades]
30 BlPitchF(1) - Blade 1 final pitch for pitch maneuvers (degrees)
30 BlPitchF(2) - Blade 2 final pitch for pitch maneuvers (degrees)
30 BlPitchF(3) - Blade 3 final pitch for pitch maneuvers (degrees) [unused for 2 blades]
---------------------- ENVIRONMENTAL CONDITIONS --------------------------------
9.8 Gravity - Gravitational acceleration (m/s^2)
---------------------- FEATURE FLAGS -------------------------------------------
True FlapDOF1 - First flapwise blade mode DOF (flag)
False FlapDOF2 - Second flapwise blade mode DOF (flag)
True EdgeDOF - First edgewise blade mode DOF (flag)
False TeetDOF - Rotor-teeter DOF (flag) [unused for 3 blades]
True DrTrDOF - Drivetrain rotational-flexibility DOF (flag)
True GenDOF - Generator DOF (flag)
False YawDOF - Yaw DOF (flag)
True TwFADOF1 - First fore-aft tower bending-mode DOF (flag)
False TwFADOF2 - Second fore-aft tower bending-mode DOF (flag)
True TwSSDOF1 - First side-to-side tower bending-mode DOF (flag)
False TwSSDOF2 - Second side-to-side tower bending-mode DOF (flag)
True CompAero - Compute aerodynamic forces (flag)
False CompNoise - Compute aerodynamic noise (flag)
---------------------- INITIAL CONDITIONS --------------------------------------
0.0 OoPDefl - Initial out-of-plane blade-tip displacement (meters)
0.0 IPDefl - Initial in-plane blade-tip deflection (meters)
0.0 TeetDefl - Initial or fixed teeter angle (degrees) [unused for 3 blades]
0.0 Azimuth - Initial azimuth angle for blade 1 (degrees)
20.4626 RotSpeed - Initial or fixed rotor speed (rpm)
0.0 NacYaw - Initial or fixed nacelle-yaw angle (degrees)
0.0 TTDspFA - Initial fore-aft tower-top displacement (meters)
0.0 TTDspSS - Initial side-to-side tower-top displacement (meters)
---------------------- TURBINE CONFIGURATION -----------------------------------
35.0 TipRad - The distance from the rotor apex to the blade tip (meters)
1.75 HubRad - The distance from the rotor apex to the blade root (meters)
1 PSpnElN - Number of the innermost blade element which is still part of the pitchable portion of the blade for partial-span pitch control [1 to BldNodes] [CURRENTLY IGNORED] (-)
0.0 UndSling - Undersling length [distance from teeter pin to the rotor apex] (meters) [unused for 3 blades]
0.0 HubCM - Distance from rotor apex to hub mass [positive downwind] (meters)
-3.3 OverHang - Distance from yaw axis to rotor apex [3 blades] or teeter pin [2 blades] (meters)
-0.1449 NacCMxn - Downwind distance from the tower-top to the nacelle CM (meters)
0.0 NacCMyn - Lateral distance from the tower-top to the nacelle CM (meters)
1.3890 NacCMzn - Vertical distance from the tower-top to the nacelle CM (meters)
82.39 TowerHt - Height of tower above ground level [onshore] or MSL [offshore] (meters)
1.61 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (meters)
0.0 TwrRBHt - Tower rigid base height (meters)
-5.0 ShftTilt - Rotor shaft tilt angle (degrees)
0.0 Delta3 - Delta-3 angle for teetering rotors (degrees) [unused for 3 blades]
0.0 PreCone(1) - Blade 1 cone angle (degrees)
0.0 PreCone(2) - Blade 2 cone angle (degrees)
0.0 PreCone(3) - Blade 3 cone angle (degrees) [unused for 2 blades]
0.0 AzimB1Up - Azimuth value to use for I/O when blade 1 points up (degrees)
---------------------- MASS AND INERTIA ----------------------------------------
0.0 YawBrMass - Yaw bearing mass (kg)
51.170E3 NacMass - Nacelle mass (kg)
15.148E3 HubMass - Hub mass (kg)
0.0 TipMass(1) - Tip-brake mass, blade 1 (kg)
0.0 TipMass(2) - Tip-brake mass, blade 2 (kg)
0.0 TipMass(3) - Tip-brake mass, blade 3 (kg) [unused for 2 blades]
49.130E3 NacYIner - Nacelle inertia about yaw axis (kg m^2)
53.036 GenIner - Generator inertia about HSS (kg m^2)
34.600E3 HubIner - Hub inertia about rotor axis [3 blades] or teeter axis [2 blades] (kg m^2)
---------------------- DRIVETRAIN ----------------------------------------------
100.0 GBoxEff - Gearbox efficiency (%)
100.0 GenEff - Generator efficiency [ignored by the Thevenin and user-defined generator models] (%)
87.965 GBRatio - Gearbox ratio (-)
False GBRevers - Gearbox reversal {T: if rotor and generator rotate in opposite directions} (flag)
9999.9 HSSBrTqF - Fully deployed HSS-brake torque (N-m)
9999.9 HSSBrDT - Time for HSS-brake to reach full deployment once initiated (sec) [used only when HSSBrMode=1]
"" DynBrkFi - File containing a mech-gen-torque vs HSS-speed curve for a dynamic brake [CURRENTLY IGNORED] (quoted string)
5.6E9 DTTorSpr - Drivetrain torsional spring (N-m/rad)
1.0E7 DTTorDmp - Drivetrain torsional damper (N-m/(rad/s))
---------------------- SIMPLE INDUCTION GENERATOR ------------------------------
9999.9 SIG_SlPc - Rated generator slip percentage (%) [used only when VSContrl=0 and GenModel=1]
9999.9 SIG_SySp - Synchronous (zero-torque) generator speed (rpm) [used only when VSContrl=0 and GenModel=1]
9999.9 SIG_RtTq - Rated torque (N-m) [used only when VSContrl=0 and GenModel=1]
9999.9 SIG_PORt - Pull-out ratio (Tpullout/Trated) (-) [used only when VSContrl=0 and GenModel=1]
---------------------- THEVENIN-EQUIVALENT INDUCTION GENERATOR -----------------
9999.9 TEC_Freq - Line frequency [50 or 60] (Hz) [used only when VSContrl=0 and GenModel=2]
9998 TEC_NPol - Number of poles [even integer > 0] (-) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_SRes - Stator resistance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_RRes - Rotor resistance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_VLL - Line-to-line RMS voltage (volts) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_SLR - Stator leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_RLR - Rotor leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_MR - Magnetizing reactance (ohms) [used only when VSContrl=0 and GenModel=2]
---------------------- PLATFORM ------------------------------------------------
0 PtfmModel - Platform model {0: none, 1: onshore, 2: fixed bottom offshore, 3: floating offshore} (switch)
"" PtfmFile - Name of file containing platform properties (quoted string) [unused when PtfmModel=0]
---------------------- TOWER ---------------------------------------------------
10 TwrNodes - Number of tower nodes used for analysis (-)
"Baseline_Tower.dat" TwrFile - Name of file containing tower properties (quoted string)
---------------------- NACELLE-YAW ---------------------------------------------
0.0 YawSpr - Nacelle-yaw spring constant (N-m/rad)
0.0 YawDamp - Nacelle-yaw damping constant (N-m/(rad/s))
0.0 YawNeut - Neutral yaw position--yaw spring force is zero at this yaw (degrees)
---------------------- FURLING -------------------------------------------------
False Furling - Read in additional model properties for furling turbine (flag)
"" FurlFile - Name of file containing furling properties (quoted string) [unused when Furling=False]
---------------------- ROTOR-TEETER --------------------------------------------
0 TeetMod - Rotor-teeter spring/damper model {0: none, 1: standard, 2: user-defined from routine UserTeet} (switch) [unused for 3 blades]
0.0 TeetDmpP - Rotor-teeter damper position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetDmp - Rotor-teeter damping constant (N-m/(rad/s)) [used only for 2 blades and when TeetMod=1]
0.0 TeetCDmp - Rotor-teeter rate-independent Coulomb-damping moment (N-m) [used only for 2 blades and when TeetMod=1]
0.0 TeetSStP - Rotor-teeter soft-stop position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetHStP - Rotor-teeter hard-stop position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetSSSp - Rotor-teeter soft-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
0.0 TeetHSSp - Rotor-teeter hard-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
---------------------- TIP-BRAKE -----------------------------------------------
0.0 TBDrConN - Tip-brake drag constant during normal operation, Cd*Area (m^2)
0.0 TBDrConD - Tip-brake drag constant during fully-deployed operation, Cd*Area (m^2)
0.0 TpBrDT - Time for tip-brake to reach full deployment once released (sec)
---------------------- BLADE ---------------------------------------------------
"Baseline_Blade.dat" BldFile(1) - Name of file containing properties for blade 1 (quoted string)
"Baseline_Blade.dat" BldFile(2) - Name of file containing properties for blade 2 (quoted string)
"Baseline_Blade.dat" BldFile(3) - Name of file containing properties for blade 3 (quoted string) [unused for 2 blades]
---------------------- AERODYN -------------------------------------------------
"Test14_AD.ipt" ADFile - Name of file containing AeroDyn input parameters (quoted string)
---------------------- NOISE ---------------------------------------------------
"" NoiseFile - Name of file containing aerodynamic noise input parameters (quoted string) [used only when CompNoise=True]
---------------------- ADAMS ---------------------------------------------------
"Baseline_ADAMS_LIN.dat"ADAMSFile - Name of file containing ADAMS-specific input parameters (quoted string) [unused when ADAMSPrep=1]
---------------------- LINEARIZATION CONTROL -----------------------------------
"Baseline_Linear.dat" LinFile - Name of file containing FAST linearization parameters (quoted string) [unused when AnalMode=1]
---------------------- OUTPUT --------------------------------------------------
True SumPrint - Print summary data to "<RootName>.fsm" (flag)
True TabDelim - Generate a tab-delimited tabular output file. (flag)
"ES10.3E2" OutFmt - Format used for tabular output except time. Resulting field should be 10 characters. (quoted string) [not checked for validity!]
10.0 TStart - Time to begin tabular output (s)
10 DecFact - Decimation factor for tabular output {1: output every time step} (-)
1.0 SttsTime - Amount of time between screen status messages (sec)
0.0 NcIMUxn - Downwind distance from the tower-top to the nacelle IMU (meters)
0.0 NcIMUyn - Lateral distance from the tower-top to the nacelle IMU (meters)
0.0 NcIMUzn - Vertical distance from the tower-top to the nacelle IMU (meters)
0.99 ShftGagL - Distance from rotor apex [3 blades] or teeter pin [2 blades] to shaft strain gages [positive for upwind rotors] (meters)
2 NTwGages - Number of tower nodes that have strain gages for output [0 to 9] (-)
4,7 TwrGagNd - List of tower nodes that have strain gages [1 to TwrNodes] (-) [unused if NTwGages=0]
0 NBlGages - Number of blade nodes that have strain gages for output [0 to 9] (-)
0 BldGagNd - List of blade nodes that have strain gages [1 to BldNodes] (-) [unused if NBlGages=0]
OutList - The next line(s) contains a list of output parameters. See OutList.txt for a listing of available output channels, (-)
"HSShftV"
"GenTq"
"GenPwr"
"LSSTipVxa"
"LSShftFxa"
"LSShftMxa"
"RotPwr"
"RootFxc1"
"RootFxc2"
"RootFxc3"
"RootFyc1"
"RootFyc2"
"RootFyc3"
"RootFzc1"
"RootFzc2"
"RootFzc3"
"RootMxc1"
"RootMxc2"
"RootMxc3"
"RootMyc1"
"RootMyc2"
"RootMyc3"
"RootMzc1"
"RootMzc2"
"RootMzc3"
"RotCp"
"HorWindV"
"HorWndDir"
"TSR"
END of FAST input file (the word "END" must appear in the first 3 columns of this last line).
--------------------------------------------------------------------------------

[code]1.5 MW baseline aerodynamic parameters for FAST certification test #14.
SI SysUnits - System of units for used for input and output [must be SI for FAST] (unquoted string)
STEADY StallMod - Dynamic stall included [BEDDOES or STEADY] (unquoted string)
NO_CM UseCm - Use aerodynamic pitching moment model? [USE_CM or NO_CM] (unquoted string)
EQUIL InfModel - Inflow model [DYNIN or EQUIL] (unquoted string)
WAKE IndModel - Induction-factor model [NONE or WAKE or SWIRL] (unquoted string)
1.0E-6 AToler - Induction-factor tolerance (convergence criteria) (-)
PRANDtl TLModel - Tip-loss model (EQUIL only) [PRANDtl, GTECH, or NONE] (unquoted string)
PRANDtl HLModel - Hub-loss model (EQUIL only) [PRANdtl or NONE] (unquoted string)
“Wind\WP_Baseline\Shr18_30.WND” WindFile - Name of file containing wind data (quoted string)
84.2876 HH - Wind reference (hub) height [TowerHt+Twr2Shft+OverHang*SIN(ShftTilt)] (m)
0.0 TwrShad - Tower-shadow velocity deficit (-)
9999.9 ShadHWid - Tower-shadow half width (m)
9999.9 T_Shad_Refpt - Tower-shadow reference point (m)
1.225 AirDens - Air density (kg/m^3)
1.4639E-5 KinVisc - Kinematic air viscosity (m^2/sec)
0.005 DTAero - Time interval for aerodynamic calculations (sec)
4 NumFoil - Number of airfoil files (-)
“AeroData\WP_Baseline\cylinder.dat” FoilNm - Names of the airfoil files [NumFoil lines] (quoted strings)
“AeroData\WP_Baseline\s818_2703.dat”
“AeroData\WP_Baseline\s825_2103.dat”
“AeroData\WP_Baseline\s826_1603.dat”
15 BldNodes - Number of blade nodes used for analysis (-)
RNodes AeroTwst DRNodes Chord NFoil PrnElm
2.85833 11.10 2.21667 1.949 1 NOPRINT
5.07500 11.10 2.21667 2.269 2 NOPRINT
7.29167 11.10 2.21667 2.589 2 NOPRINT
9.50833 10.41 2.21667 2.743 2 NOPRINT
11.72500 8.38 2.21667 2.578 2 NOPRINT
13.94167 6.35 2.21667 2.412 2 NOPRINT
16.15833 4.33 2.21667 2.247 2 NOPRINT
18.37500 2.85 2.21667 2.082 3 NOPRINT
20.59167 2.22 2.21667 1.916 3 NOPRINT
22.80833 1.58 2.21667 1.751 3 NOPRINT
25.02500 0.95 2.21667 1.585 3 NOPRINT
27.24167 0.53 2.21667 1.427 3 NOPRINT
29.45833 0.38 2.21667 1.278 3 NOPRINT
31.67500 0.23 2.21667 1.129 4 NOPRINT
33.89167 0.08 2.21667 0.980 4 NOPRINT

[/code]

Linearised file(test14.lin) generated during linearisation is attached herewithtest14.rar (66.1 KB). In this file :

i am using wind speed of 18m/sec at 30 degree in WND file, but wind speed and direction is coming out to be zero in above shown “Order of Input Wind Disturbances in Linearized State Matrices” (i tried with changing several parameters but finally no change happens).
Moreover it is showing correctly 30m/sec(Row 27 = HorWindV (m/sec) , Row 28 = HorWndDir (deg) ) in output measurements .

I will be highly obliged if you could help me to overcome this problem, i am unable to make out what’s wrong with wind speed and direction.

We intentionally took the inflow out of FAST v7.00.00a-bjj to aid in modularizing our codes. FAST no longer knows the details of the HH wind input file, so it can’t print those values. As a result, the linearization summary file shows all zeros for the operating points from the inflow (wind input disturbances). These numbers are just direct copies of the values in the HH file, though, so hopefully you can get the numbers you need without too much trouble. (It’s using the correct values, just not printing them in the linearization file.)

We hope to redo the way the linearization is specified in future versions.

Thanks for helping a lot. I am really thankful to you from deep of my heart.

Now i am facing problem in FAST’s interface with simulink.
I will summarize the steps in detail : For linear model:
I have linearised the model at wind speed 12m/sec,pitch angle 7.286 degree.Linearized file is:

5: when i compare the response for step input in wind from 12 to 13 m/sec for non-linear(red) as well as linear model(blue), i get huge error in response of generator angular speed. That error is obviously in linear model(blue curve).

please suggest me if i can use this simplified model in simulink,if not please suggest me appropriate references to follow.
If there is any other error please suggest.
thanks once again for consideration.

I’m not sure I understand all of what you’ve done. Please clarify for me by answering a few questions:

*What generator torque model was applied when the model was linearized?
*What torque and pitch controller inputs are applied in the linear model (step 4) and nonlinear model to obtain the plot shown in step 5?
*Were the nonlinear results created by a simulation with the FAST executable or S-Function?

Also, I see that you’ve linearized the model about initial conditions instead of about a steady-state condition. You must be careful how you use a linear model that was not derived about a steady-state condition. See the following topic for a discussion of the some of the potential problems: http://forums.nrel.gov/t/fast-model-linearization/243/1. I suggest that you relinearize your model about a steady-state condition before comparing the linear and nonlinaer solutions.

*What generator torque model was applied when the model was linearized?
I am using SIMPLE VARIABLE SPEED GENERATOR model for linearisation [ VSContrl=1 ]

What torque and pitch controller inputs are applied in the linear model (step 4) and nonlinear model to obtain the plot shown in step 5?

i am applying : Input to linear model:
Pitch controller input: step wind input :pitch change from 0.12717 rad to 0.1786rad at 50 sec along with step wind change at 50 sec to get plot shown in step 5
Torque controller input:Constant torque=8376.58 Nm

Input to non-linear model:

Pitch controller input: pitch change from 0.12717 rad to 0.1786rad at 50 sec along with step wind change at 50 sec to get plot shown in step 5 [PCMode=2]
Torque controller input: defined by simple variable speed model [VSContrl=1]

2:In fast input file for simulink interface, i am using a simple variable speed model that uses the next four input parameters [ VSContrl=1 ] to determine the generator torque to non-linear model in step 5

*Were the nonlinear results created by a simulation with the FAST executable or S-Function?
non-linear simulation is created by S-function using simulink.
i have calculated the steady point by trim analysis,then used those points as initial points for linearisation.

First, did you really mean you are using AvgAMat etc. instead of the MBC_AvgA etc.? AvgAMat etc. are created by MBC’s GetMats.m script and are the azimuth-averaged matrices before applying MBC. Azimuth-averaging before MBC is much less useful and may not lead to good comparisons with the nonlinear model. Instead you should form your state-space system with MBC_AvgA etc., which are the azimuth-averaged matrices after MBC has been applied. MBC_AvgA etc. are created by MBC’s mbc3.m script.

Second, the linear model characterizes the linear system dynamics for small perturbations about the operating point that was used to linearize the model. All states, inputs, and outputs of the linear model are the perturbations about the operating point. That is, a paremeter x in the linear model corresponds to the parameter ( q - qop ) in the nonlinear model, where q is the parameter in the nonlinear model and qop is the value of the parameter when the model was linearized. For example, if you want the pitch to change from 0.12717 to 0.1786 rad, in the linear model you should input a step change from 0 to 0.05143 rad because the model was linearized about 0.12717 rad. This also applies to the wind, torque, and the linear model’s states and outputs. (The parameters of the linear model that were originally in the rotating reference frame in the nonlinear model are also tranformed to the nonrotating frame by MBC.)

Dear Jason
I start linearising test 11 as
CompElast 1
1CompInflow
CompAero 0
CompServo1
2 Gentype
I input power and torque as two step inputs, linearizing conditions as following
True Linearize
LinTimes 30, 60
LinInputs 1
LinOutputs 1
False LinOutJac
False LinOutMod
I run GetMats-f8 and mbc3, the output of mbc3.m was not include MBC_D, MBC_Dd, MBC_C, MBC_B , MBC_Bd

I need these matrices to build linear model, you advice Manish to use them Can you explain why these matrices do not calculated ?
I follow Manish steps and build Simulink model for linearized system and write this code

B = [AvgBMat AvgBdMat];
% B = [MBC_B MBC_Bd] ;
C= AvgCMat;
%C = MBC_C ;
D= [AvgDMat AvgDdMat] ;
% D = [MBC_D MBC_Dd] ;

TMax = 20;
% wt=ss(A,B,C,D)
% run the model
sim(‘linOpenLoopsys’,[0,TMax]);
it gives me the following error and warning

Warning: Cannot find an exact case-sensitive match for the model or library name ‘linOpenLoopsyss’.
Using the closest case-insensitive match: ‘linopenloopsyss’.
Case-insensitive matching will be removed in a future release. Specify exact case instead.

In matrices (line 24)
Error using matrices (line 24)
Error due to multiple causes.
Caused by:
Error using matrices (line 24)
Error in port widths or dimensions. Output port 1 of ‘linopenloopsyss/Mux’ is a one dimensional vector
with 3 elements. Error using matrices (line 24)
Error in port widths or dimensions. Invalid dimension has been specified for input port 1 of
‘linopenloopsyss/State-Space’.

Note that
I make output array not time series
Can you helping me in solving this error ?

My understanding of what you said is that your linearization output includes the A, B, C, and D matrices, but after running GetMats_f8.m and mbc3.m, you get MBC_A, but don’t get MBC_B, MBC_C, and MBC_D. Is my understanding, correct? After running GetMats_f8.m, do you get BMat, CMat, and DMat in the MATLAB workspace?

Please note that in FAST v8 the Bd and Dd matrices have been merged into the B and D matrices, respectively.

If AMat, BMat ,CMat DMat are generated by GetMats_f8.m, I don’t see how mbc3.m would not generate MBC_A, MBC_B, MBC_C, and MBC_D. I suggest that you step through mbc3.m to debug.

Dear Jason
when i linearized Teat 11, the lin file gives
1- Rotor Speed: 0.3000 rad/s
2. Azimuth: 3.1309 rad
2- values for continuous states
3- values for continuous state derivatives
4- values for outputs ex : ( 2.864E+00 F ED RotSpeed, (rpm))
5- values for inputs
6- system martix A,B,C,D
now i like to put values of inputs and states on nonlinear model so that output of nonlinear equals linear output ?

in general when linearizing any system at operating point (X,U-y), after that apply (X,U) on nonlinear the output must equal y
i like to do this on FASTv8 ?