Simulation platform for Wind Turbines
by
Professor Frede Blaabjerg
Aalborg University
fbl@iet.auc.dk
http://www.iet.auc.dk/~fbl/
November 28, 2003
1.Background
2.Wind turbine concepts
3.Basic model library
4.Simulation examples
5.Conclusion
Why
¾Electrical system of the wind turbine in steady progress and become more and more important
¾Wind turbines grow in size (3-5 MW)
9Virtual prototyping is the only method for analysis and evaluation
Goals
¾Develop an extended simulation platform for electrical parts in wind turbines
¾Develop models which may used in mechanical / aeroelastical design tools like HAWC
DigSilent
electrical power system
simulation tool ¾aerodynamic models
¾aeroelastic models
¾turbulent wind model
Mechanical aspects Electrical aspects
HAWC
aeroelastic simulation tool
wind turbine
¾grid components library
¾dynamic simulation
language
Matlab/Simulink
general
developer tool
wind turbine/
wind farm
¾dynamic behavior of power systems
¾assesment of power
¾RMS and EMT simulations
Saber
advanced
simulation tool
¾Hydraulic
¾Mechanic
simulates physical effects
in different engineering
domains
¾Magnetic
¾Thermal
¾ Electric
¾ Electronic
¾ Digital control
¾ Embedded software
¾calculation of mechanical loads on
the structure
¾dynamic behavior of wind turbine
¾focus on frequency range 0 - 20 Hz
wind turbine/
power converter
5S:bj-jn\simulation Platform for Wind Turbines
Modelling aspects
Aspect Model level Time scale Tool Wind turbines mechanical loads RMS10-1s –103s HAWC
Wind turbines power quality RMS10-1s –103s DigSilent
Wind turbine control system RMS/EMT10-3s –102s Matlab
Wind turbine switchings EMT10-3s –101s DigSilent/SABER Grid faults EMT10-6s –10-1s DigSilent Power electronic control and design EMT10-9s –10-2s SABER
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Active stall/stall wind turbine
¾Fixed Speed
¾Squirrel-Cage Induction Generator ¾Soft-starter, Capacitor Bank
Pitch control wind turbine
¾Variable Speed
¾Squirrel-Cage Induction Generator ¾Back-to-Back Power Converter
Capacitor
Bank
By-pass
transformer
grid
AC
AC G
drive
train wind
SCIG
Soft-starter
drive train
wind
SCIG
AC AC G
transformer
grid/stand alone
Power Converter
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Pitch control wind turbine ¾Variable Speed
¾Double-Fed Induction Generator ¾Back-to-Back Power Converter
Pitch control wind turbine ¾Variable Speed ¾Multi-Pole Synchronous Generator
–direct driven ¾Rectifier + Inverter
drive train
wind
DFIG
AC
AC
G
transformer
grid
wind
SG
AC AC G
transformer
grid/stand alone
Power Converter
Wind Turbine Blockset
in Matlab/Simulink
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¾Dynamic models
9dq/dq models
9abc/abc models
¾Reduced order models ¾Steady-state models ¾Optimized for speed (C S-Function version)
¾Squirrel-cage IG
¾Doubly-fed IG
¾Synchronous Machine ¾PMSM
Simulation speed important
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¾wind model –take into account the rotational turbulences and the tower shadow
¾wind turbine rotor –based on torque coefficient look-up tablel ¾different drive-train models
¾one-mass model ¾
two-mass model
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¾rectifiers
¾voltage source converters ¾soft-starter
9star 9delta
9branch-delta
¾modulation strategies
¾switching models ¾
average models
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¾abc/abc model for 3-phase 2-winding transformer ¾
take into account iron losses and core geometry
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Simulink example
Simulink simulation results
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Interface variables to the grid:
voltage current
Gear
Gear
Active stall wind turbine with asynchronous generator
Pitch control wind turbine with doubly fed generator
HAWC kernel
1. Generator model (directly in HAWC)
-SCIG -DFIG 2. Power converter control (dll subroutine)
-frequency converter -softstarter 3. Wind turbine control (dll subroutine)
Soft-starter
Power converter
Implementation boundaries
HAWC dll
HAWC
HAWC: Active stall control
6 m/s
6 m/s Green: Old Model
Red:New model
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DFIG control
Power control loop
Speed control loop
Wind turbine control
Rotor side converter control Network side converter control
Measurement grid point M
θ
AC DC
AC
DC I rotor
gen
ωPWM
PWM
N
T
ref grid
P ref grid
Q meas dc
U meas grid
P meas grid
P meas grid
Q meas ac
I ref dc
U rated ref grid
P ,Digsilent: Variable speed/ variable pitch wind turbine
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25
02000M e c h a n i c a l p o w e r [k W ]
Power curve
Power o ptimisation
Power l imitation
s s Dynamic s
peed range A B rated
ω0
200
400
600
800
1000
1200
1400
1600
1800
2000
500
1000
150020002500P-ωcurve
Generator speed [rpm]
5
101520500
1000150022002500
Wind speed [m/s]
Power curve Power o ptimisation Power l imitation v a
r . r e f .p e e d
f i x
e d r e
f .p e e d
Dynamic s peed range A
B
A
B
C
D
C, D
mec
P u rated
nom
gen n AB:
R
u
u and C
opt
ref rot
opt
opt
p
nom
rot
rot
λ
ω
λ
θ
ω
ω
=
⇒⇒→≤)(max rated mec
mec
nom rot rot
P
P <>ωω
BC:
θ
λω
λω
ω
⇒⇒=
⇒
=→
)
()(opt p
nom rot
nom rot
ref rot
C
u
R
u CD:
rated
mec
ref mec
nom rot
rot P P =>ω
ω
[]
θ
ω
πρλω
ω
⇒
=
⇒
=→
3
5
3
)
(2)(nom rot
rated
mec p
nom rot
ref rot R u P u C
M e c h a n i c a l p o w e r [k W ]
E l e c t r i c a l p o w e r [k W ]
Digsilent: Control strategies
600.00
479.98
359.96
239.94
119.92
-0.1000..
2.4742
2.3254
2.1765
2.0277
1.8788
1.7300
Gen_PQ_controller: P1
600.00
479.98
359.96
239.94
119.92
-0.1000..
27.182
24.935
22.688
20.441
18.194
15.947
Rotor wind model: wsfic
600.00
479.98
359.96
239.94
119.92
-0.1000..
1767.2
1730.8
1694.4
1657.9
1621.5
1585.0
Speed controller model: rotation_real
Speed controller model: rotation_ref
600.00
479.98
359.96
239.94
119.92
-0.1000..
28.381
25.594
22.806
20.018
17.230
14.442
Power control schedulling model: pitch
15m/s comparison1
Simulation: error and wind
Date: 5/25/2003
Annex: /1
D
I
g
S
I
L
E
N
T Digsilent: Power limitation with gain schedulling(wind22 m/s)
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SABER: Saber diagram of a directly grid-connected squirrel-cage induction generator
¾Wind Turbine Toolbox(Matlab/Simulink)
¾Improved models HAWC (IG, DFIG)
¾DIgSILENT Power Factory(Now a toolbox)
¾Toolbox for SABER (A toolbox)
¾Validated models (Wind turbine and wind farms)
¾Simulations have shown new behaviours
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Virtual Electrical Prototyping of Wind Turbines Focus on
1.New models for new configurations
2.Improved models (Special cases, grid, generator,
power electronics)
3.Advanced control of turbine
4.Optimization of wind turbines
5.Models in use(Wind turbine manufacturer specific)
24S:bj-jn\simulation Platform for Wind Turbines。
