Simulink + Generator model Questions

Hello Everyone:

I am trying to currently model WT model using FAST on Simulink and electrical generator+electrical load model in either MATLAB/SimPower or Dymola. I expect to create very detailed models on the electrical side modeling with grid architecture as well at some point. Here are my conceived future steps and related questions:

  1. I am going to use the Simulink model “Test01_SIG” that comes with the installer files for FAST. My first task was getting it work on Simulink as suggested in FAST manual ( wind.nrel.gov/designcodes/simula … t/FAST.pdf ). I modified the Simsetup. m and Test01.fst files accordingly as shown in the following:

Simsetup.m

[code]% This script creates necessary workspace variables to run a Simulink model
% using the FAST dynamics and aerodynamic S-function block. Before running
% a simulation, the character array, input_fast, must contain the FAST
% input file name, and the script Read_FAST_Input.m must run.

clear all;

% Prompt the user for the input file name.
disp( ’ -------------------------------------------------’ );
disp( ’ Enter the name of the FAST input file to read ’ );
disp( ’ -------------------------------------------------’ );
input_fast = [ input(’ < ',‘s’)]; % FAST (.fst) filename

% Read FAST input file and set initial conditions
Read_FAST_Input

%% ------------------------------------------------------------------------
% Place all controller related parameters here.
%
% Simple Induction Generator Example ======================================
% To model a simple induction generator in Simulink use model Test01_SIG.mdl.
% The following parameters duplicate those used in Certification Test #01.
% Change Test01.fst as follows:
ADAMSPrep = 1;
VSContrl = 3;
% Add “LSSGagVxa” to OutList
% >>>>>>>Comment (by Amit Mohanty): <<<<<<<<<<<
% >>>Added LSSGagVxa to OutList in Test01.fst <<<

%
% Remove comment indication (%) from following lines:
%
% >>>>>>>Comment (by Amit Mohanty): <<<<<<<<<<<
% >>>Uncommented following lines <<<
GenEff = 100.0; % - Generator efficiency [ignored by the Thevenin and user-defined generator models] (%)
GBRatio = 22.5; % - Gearbox ratio (-)
SIG_SlPc = 1.5125; % - Rated generator slip percentage [>0] (%) Now HSS side!
SIG_SySp = 1200.0; % - Synchronous (zero-torque) generator speed [>0] (rpm) Now HSS side!
SIG_RtTq = 1367.9; % - Rated torque [>0] (N-m) Now HSS side!
SIG_PORt = 2.0; % - Pull-out ratio (Tpullout/Trated) [>1] (-)

SIG_SySp = SIG_SySppi/30; % convert to rad/s
SIG_RtSp = SIG_SySp
(1.0+0.01SIG_SlPc);
SIG_POS1=SIG_PORt
(SIG_RtSp-SIG_SySp);
SIG_POTq=SIG_RtTq*SIG_PORt;
SIG_Slop=SIG_RtTq/(SIG_RtSp - SIG_SySp);

%% ========================================================================

% If your there is an error that requires you to restart the Simulink
% simulation before FAST terminates properly (you should see the Simulation
% Time Ratio statistics printed to the Matlab command window when it
% terminates properly), call the FAST_SFunc routine with FLAG=9, like this:
%
% FAST_SFunc(0,,,9)
%
% It will close open files and deallocate memory. If you do not do this,
% you may have to close Matlab to release locks on open files and/or
% free the memory allocated in FAST_SFunc before you can start your
% Simulink model again.[/code]

Test01.fst

[code]--------------------------------------------------------------------------------
------- FAST INPUT FILE --------------------------------------------------------
FAST certification Test #01: AWT-27CR2 with many DOFs with fixed yaw error and steady wind.
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)
1 AnalMode - Analysis mode {1: Run a time-marching simulation, 2: create a periodic linearized model} (switch)
2 NumBl - Number of blades (-)
20.0 TMax - Total run time (s)
0.004 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)
0.0000 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)
0.0000 TPCOn - Time to enable active pitch control (s) [unused when PCMode=0]
3 VSContrl - Variable-speed control mode {0: none, 1: simple VS, 2: user-defined from routine UserVSCont, 3: user-defined from Simulink} (switch)
9999.9 VS_RtGnSp - Rated generator speed for simple variable-speed generator control (HSS side) (rpm) [used only when VSContrl=1]
9999.9 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]
9999.9 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]
9999.9 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]
-1.0 BlPitch(1) - Blade 1 initial pitch (degrees)
-1.0 BlPitch(2) - Blade 2 initial pitch (degrees)
-1.0 BlPitch(3) - Blade 3 initial pitch (degrees) [unused for 2 blades]
-1.0 BlPitchF(1) - Blade 1 final pitch for pitch maneuvers (degrees)
-1.0 BlPitchF(2) - Blade 2 final pitch for pitch maneuvers (degrees)
-1.0 BlPitchF(3) - Blade 3 final pitch for pitch maneuvers (degrees) [unused for 2 blades]
---------------------- ENVIRONMENTAL CONDITIONS --------------------------------
9.80665 Gravity - Gravitational acceleration (m/s^2)
---------------------- FEATURE FLAGS -------------------------------------------
True FlapDOF1 - First flapwise blade mode DOF (flag)
True FlapDOF2 - Second flapwise blade mode DOF (flag)
True EdgeDOF - First edgewise blade mode DOF (flag)
True 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)
True TwFADOF2 - Second fore-aft tower bending-mode DOF (flag)
True TwSSDOF1 - First side-to-side tower bending-mode DOF (flag)
True 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)
53.333 RotSpeed - Initial or fixed rotor speed (rpm)
-15.0 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 -----------------------------------
13.757 TipRad - The distance from the rotor apex to the blade tip (meters)
1.184 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] (-)
0.153 UndSling - Undersling length [distance from teeter pin to the rotor apex] (meters) [unused for 3 blades]
0.406 HubCM - Distance from rotor apex to hub mass [positive downwind] (meters)
2.432 OverHang - Distance from yaw axis to rotor apex [3 blades] or teeter pin [2 blades] (meters)
0.193 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)
0.684 NacCMzn - Vertical distance from the tower-top to the nacelle CM (meters)
41.980 TowerHt - Height of tower above ground level [onshore] or MSL [offshore] (meters)
0.692 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (meters)
0.0 TwrRBHt - Tower rigid base height (meters)
0.0 ShftTilt - Rotor shaft tilt angle (degrees)
0.0 Delta3 - Delta-3 angle for teetering rotors (degrees) [unused for 3 blades]
7.0 PreCone(1) - Blade 1 cone angle (degrees)
7.0 PreCone(2) - Blade 2 cone angle (degrees)
7.0 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)
5015.43 NacMass - Nacelle mass (kg)
1330.00 HubMass - Hub mass (kg)
11.34 TipMass(1) - Tip-brake mass, blade 1 (kg)
11.34 TipMass(2) - Tip-brake mass, blade 2 (kg)
11.34 TipMass(3) - Tip-brake mass, blade 3 (kg) [unused for 2 blades]
4604.84 NacYIner - Nacelle inertia about yaw axis (kg m^2)
59.26 GenIner - Generator inertia about HSS (kg m^2)
335.34 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] (%)
22.5 GBRatio - Gearbox ratio (-)
False GBRevers - Gearbox reversal {T: if rotor and generator rotate in opposite directions} (flag)
6000.0 HSSBrTqF - Fully deployed HSS-brake torque (N-m)
0.5 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)
50.0E6 DTTorSpr - Drivetrain torsional spring (N-m/rad)
1.0E6 DTTorDmp - Drivetrain torsional damper (N-m/(rad/s))
---------------------- SIMPLE INDUCTION GENERATOR ------------------------------
1.5125 SIG_SlPc - Rated generator slip percentage (%) [used only when VSContrl=0 and GenModel=1]
1200.0 SIG_SySp - Synchronous (zero-torque) generator speed (rpm) [used only when VSContrl=0 and GenModel=1]
1367.9 SIG_RtTq - Rated torque (N-m) [used only when VSContrl=0 and GenModel=1]
2.0 SIG_PORt - Pull-out ratio (Tpullout/Trated) (-) [used only when VSContrl=0 and GenModel=1]
---------------------- THEVENIN-EQUIVALENT INDUCTION GENERATOR -----------------
60.0 TEC_Freq - Line frequency [50 or 60] (Hz) [used only when VSContrl=0 and GenModel=2]
6 TEC_NPol - Number of poles [even integer > 0] (-) [used only when VSContrl=0 and GenModel=2]
0.0185 TEC_SRes - Stator resistance (ohms) [used only when VSContrl=0 and GenModel=2]
0.017 TEC_RRes - Rotor resistance (ohms) [used only when VSContrl=0 and GenModel=2]
480.0 TEC_VLL - Line-to-line RMS voltage (volts) [used only when VSContrl=0 and GenModel=2]
0.0340 TEC_SLR - Stator leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
0.0050 TEC_RLR - Rotor leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
0.7750 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 ---------------------------------------------------
21 TwrNodes - Number of tower nodes used for analysis (-)
“AWT_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 --------------------------------------------
1 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]
4.0e4 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]
180.0 TeetHStP - Rotor-teeter hard-stop position (degrees) [used only for 2 blades and when TeetMod=1]
1.0 TeetSSSp - Rotor-teeter soft-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
5.0e6 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, CdArea (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 ---------------------------------------------------
“AWT_Blades.dat” BldFile(1) - Name of file containing properties for blade 1 (quoted string)
“AWT_Blades.dat” BldFile(2) - Name of file containing properties for blade 2 (quoted string)
“AWT_Blades.dat” BldFile(3) - Name of file containing properties for blade 3 (quoted string) [unused for 2 blades]
---------------------- AERODYN -------------------------------------------------
“Test01_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 ---------------------------------------------------
“AWT_ADAMS.dat” ADAMSFile - Name of file containing ADAMS-specific input parameters (quoted string) [unused when ADAMSPrep=1]
---------------------- LINEARIZATION CONTROL -----------------------------------
“AWT_Linear.dat” LinFile - Name of file containing FAST linearization parameters (quoted string) [unused when AnalMode=1]
---------------------- OUTPUT --------------------------------------------------
True SumPrint - Print summary data to “.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)
5 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)
-0.2 ShftGagL - Distance from rotor apex [3 blades] or teeter pin [2 blades] to shaft strain gages [positive for upwind rotors] (meters)
0 NTwGages - Number of tower nodes that have strain gages for output [0 to 9] (-)
0 TwrGagNd - List of tower nodes that have strain gages [1 to TwrNodes] (-) [unused if NTwGages=0]
3 NBlGages - Number of blade nodes that have strain gages for output [0 to 9] (-)
3,5,7 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, (-)
“LSSGagPxa, TeetDefl” - LSS gage azimuth and teeter angles
“TipDxb2,TipDyb2” - Blade 2 flapwise and edgewise tip deflections
“TipALxb2,TipALyb2” - Blade 2 flapwise and edgewise tip accelerations
“Spn2ALxb1,Spn2ALyb1” - Blade 1 local flapwise and edgewise accelerations at gage #2 (Node #5)
“YawBrRDxt,YawBrRDyt” - Tower top tilt angles.
“YawBrRVxp,YawBrRVyp” - Tower top tilt rates.
“YawBrRAxp,YawBrRAyp” - Tower top tilt accelerations.
“RootMyc1, RootMxc1” - Blade 1 root OoP and IP bending moments
“RootFxc2, RootFyc2” - Blade 2 root OoP and IP shear force
“Spn3MLxb1,Spn3MLyb1” - Blade 1 local edgewise and flapwise bending moment at gage #3 (Node #7)
“RotTorq” - Rotor torque
“YawBrMzn” - Tower-top / yaw bearing yaw moment
“TwrBsMzt” - Tower base yaw moment
“LSSGagVxa”
“RotSpeed”
“RotPwr”
“BlPitch1”
END of FAST input file (the word “END” must appear in the first 3 columns of this last line).

[/code]

And then proceeded and successfully completed the simulation

  1. Now, I also want to implement pitch and yaw controller in Test01_SIG.mdl on Simulink. Is there any quick example of those two controllers on Simulink? I understand that by using different numerical values (0,1,2 to be precise) for PCMode and YCMode, I can specify whether blade pitch, nacelle yaw, and/or variable-speed torque is controlled by the Simulink model or by using one of FAST’s intrinsic controllers. Say, I want to use FAST’s intrinsic controllers (for yaw and pitch) on Simulink platform. What should I set the PCMode and YCMode to ? Is it 0 or 1? If its 1, then where are routines UserYawCont and PitchCntrl? Assuming that we resolve this question, let us move to my next step.
  1. What would be a good example of wind file to test that both those controllers work. Currently, I am using ./Wind/AWT27/Shr12_30.wnd (path with respect to FAST installation folder), which describes a constant wind velocity. I think I should use a variable speed wind profile to see the real action of pitch and yaw controller.

  2. Now, the final step is replacing the simple induction generator model with a more detailed model, say, from SimPower. In that case, what does desired power mean which is fed to first input of the “FAST Nonlinear Wind Turbine” block in "Test01_SIG.mdl.

To explain my thought process better, I am also attaching a block diagram view of how things should be connected in such a Simulink model.

Dear Amit,

Here are my answers to your questions:

  1. Algebraic loops are common in Simulink models and the solution approach you’ve used is common. More information regarding algebraic loops and their solution can be found in the forum topic found here: http://forums.nrel.gov/t/error-running-test01-sig/493/1.

  2. I’ll let others provide Simulink examples as I don’t use Simulink for controls design myself. To use FAST’s intrinsic controllers when running FAST within Simulink, set PCMode to 1 or YCMode to 1 for pitch control and yaw control, respectively. Routines PitchCntrl and UserYawCont are compiled along with the other FAST source code in the creation of the FAST S-Function used in Simulink (the *.mexw32 file). Changing routines PitchCntrl and UserYawCont requires a recompile of the FAST S-Function.

  3. Wind turbine controls engineers often use wind data with step changes in wind speed (for pitch control) or wind direction (for yaw control) to first test new controllers. AeroDyn’s so-called “hub-height wind data file” format can be used to implement these types of winds. Of course, one should eventually test controllers with realistic full-field turbulent wind generated by TurbSim across a range of operational conditions.

  4. The electrical power (GenPwr) is an indirect input to the FAST S-Function because it is used only for output purposes as described in my June 30, 2011 post in the forum topic found here: http://forums.nrel.gov/t/fast-sfunc/377/1.

Best regards,