– the challenge grid integration of wind powerieee-pels-ies.es/pels/pdf/seminarios/sevilla/03...
TRANSCRIPT
Wind Energy Grid Integration 1
Peter Zacharias, Boris Valov, Kurt Rohrig, Siegfried Heier, Gunter ArnoldUniversität Kassel, Wilhelmshöher Allee 71, D-34109 KASSEL
http://www.evs.e-technik.uni-kassel.deInstitut für Solare Energieversorgungstechnik ISET e. V., Königstor 59, D-34119 KASSEL
http://www.iset.uni-kassel.de
Grid Integration of Wind Power – the Challenge
Wind Energy Grid Integration 2
Content:
• Intro
• Prediction of generated wind power
• E.ON grid code as standard to secure grid stability
• Grid computations before installation
• Integration of off shore wind farms
• Advanced grid control with WEC’s
Wind Energy Grid Integration 3
Intro: Who we are...ISET Institute for Solar Energy Technology• headed by Prof. Schmid, founded in 1988 by
Prof. Kleinkauf• activities in solar, wind, small hydro, sea flow
and bio mass conversion into electricity• power conditioning, grid integration, remote
island grids, grid control, post-graduate studies• >80% funded by projects• 75 employees, annual turn over ~12M€
IEE/EVS Institute for Electrical Power Technology, Electr. Power Supply
• headed by Prof. Zacharias• emphasized on distributed power syst.• power electronics & control, power
conditioning, grid integration, remoteisland grids, grid control
• >50% funded by projejcts• 12 employees
Wind Energy Grid Integration 4
... and where we are:
Wind Energy Grid Integration 5
additional sourceshttp//:europa.eu.intEurObserv‘ER 2004Winpower Monthly2004
Average Wind Speed in Europe
14609
6202
3110
904
912
648
415
399
375
299
258
186
6722
51
28452
5 Ende 2003
m/s
installed Wind Power
Wind Energy Grid Integration 6
Drawn from a proposal of theEuropean Commisionconcerning gridintegration of renewable energysources 10th May 2000
Wind Energy in Europe- Targets of EU Members -
percentage of RE at electricity consumption
generated RE in TWh
Wind Energy Grid Integration 7
Wind Energy Usein Germany 12/2004
installed capacity: 16629MWnumber of WEC: 16543(DEWI Magazin, Febr. 2005 )
Generation:19,1TWh in 200329,9TWh in 2004
...representing~ half of wind energy
production in Europe~ third of wind energy
production world wide
Probably Spain will take over soon
Wind Energy Grid Integration 8
In the past: conventional generationfollows the demand
conv. generation
hours
po
wer
[M
W]
Typical load profile at the E.ON Grid
source: E.ON
Wind Energy Grid Integration 9
now: conventional generation = load – wind power
wind powerconv. power
hours
po
wer
[M
W]
Wind Energy Grid Integration 10
Wind Power is
• depending on meteorological processes,
• can not be pushed (only limited),
• but can be predicted by knowing themeteorological circumstances!
ISET developed software for wind power prediction to plan thepower plant capacities of the utility companies based on meteorological (DWD) and online wind mill data
Wind Energy Grid Integration 11
Online Data Acquisition
Data Basis:
E.ON 39 sites 1337MWVE-T 17 sites 608MWRWE 16 sites 447MWTotal: 72 sites 2392MW
Wind Energy Grid Integration 12
How it works:
1. Deviding regions into 10x10km2
areas for planning and calculation of representativeparameters
2. overall 8585 areas areconsidered monthly
3. For prediction of wind energyproduction the following input of the WEC‘s are used:• number of WEC• rated power of WEC• hub height• profile of territory• type of control of the WEC
Wind Energy Grid Integration 13
Example: 24h Wind Power Forecast for 17th to 24th Februay 2002 for the E.ON Transmission Grid
Wind Energy Grid Integration 14
win
d p
ow
er [
MW
]
time
measurementsforecast
Extended Example of 24h Forecast for Wind Power Delivery to theE.ON Transmission Grid
Wind Energy Grid Integration 15
Deviations by storm caused disconnections of WEC‘s at the 26th
February 2002 with requested Control Power of about 1590MWw
ind
po
wer
[M
W]
time
online24h forecastforecast error
Wind Energy Grid Integration 16
Matching of Power Plant + Wind Energy Generation to Demand:
forecast possible for „smooth“ weather conditions relatively precisely and currently used for power plant capacity planning in Germany
uncertainties at limit exceeding conditions like storms areautomatic switch off
Option 1: Improvement of forecast software
Option 2: Access of utilities to the control of wind farms
Option 2: Long distance energy exchange
Wind Energy Grid Integration 17
Energy Exchange between the 4 major Transmission Grid Areas in Europe
source: E.ON
Wind Energy Grid Integration 18
Energy and Data Exchange for the 4 major Energy Players in Germany
caused by EEG §14 source: RWE
Wind Energy Grid Integration 19
Natural Fluctuations of Wind Power can beForecasted/Calculated
Extreme Situations get not more Stability byWind Integration at the Current Technical Level, but could!
This is the reason to implement the E.ON GridCode into WEC performance
Wind Energy Grid Integration 20
Situation for the E.ON Transmission Grid
50 % of wind power in Germany
Concentration of wind power,
But low demand
Balance zone
36 000 km Length of lines
11 300 kmTransmission grid
Substations
HVDC links
In planning
380 kV -Line 220 kV- Line
Source: E.ON 2002
Wind Energy Grid Integration 21
⇒ Outage of the wholewind power
New solutions arerequired!
low loadWEC model: el. converter3 phase short circuit at Dollem
near Hamburg
source: E.ON 2002
Wind Energy Grid Integration 22
1. At the old Grid Code all suppliers would beswitched off at Ugrid<70%
2. For the concerned area a disappearing of max. 2,7GW installed wind power can exceed theavailable grid control power instability of thegrid
In opposite to thermal power plant turbines+generatorsWEC have small real‚ spinning reserves‘, but...
...there are many options for injection of reactivecurrent to support the current grid stage
Wind Energy Grid Integration 23
Wind farms shall be able to be operated withina given voltage and frequency bandwidth
V, %
f, Hz47,5 49 50,25 51,5
87,5
110
115
Continuousoperation
< 30 minutes
Frequency < 47,5 Hz or > 51,5 Hz: undelayed trip
P>90% P P=P P=P * (1- -------------)act act act 1,25 Hz
f – 50,25 Hz
Wind Energy Grid Integration 24
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
0,5 1,0 1,5 2,0 2,5 3,0
U[pu]
0,7
0,15
0,45
t [sec]
Requirementsto conventionalpower plants
WEC-SAFEWEC-SAFE
WEC-DISTURBEDWEC-DISTURBED
• Procedure in the event of a disturbance in the grid Automatic disconnection of the generating unit from the grid must not occur above the sketched curve progression of the line-to-line voltage.
• Active power must return directly after fault clearing with 20 % of the nominal active power of the WEC’s
• Within the hatched area an active power return with 5% of the nominal active power of the WEC’s per second is allowed. As an alternative, WEC’scan be disconnected in this area for a very short time (re-synchronization 2s after fault clearing, full active power return after 10s is required)
Requirements at Grid Voltage Dip: E.ON Grid Code
automatic disconnection only allowed below the scetched curve
Wind Energy Grid Integration 25
During fault clearing WEC‘s have to support the grid by injection of reactivecurrent!
Every generator concept acts different at the considered grid fault:
Wind Energy Grid Integration 26
0 .0 0 0 .2 5 0 .5 0 0 .7 5 1 .0 0t [s e c ]
-1
0
1
- 1 0
0
1 0
-1 0
1 0
0
P [ p .u . ]P [ p .u . ]Q [ p .u . ]Q [p .u . ]
U ( L 1 _ E , L 2 _ E , L 3 _ E ) [ p .u . ]U ( L 1 _ E , L 2 _ E , L 3 _ E ) [p .u . ]
I ( L 1 _ E , L 2 _ E , L 3 _ E ) [ p .u . ]I ( L 1 _ E , L 2 _ E , L 3 _ E ) [p .u . ]
ASG3
grid
Simple Induction Generator w/o Converter in Case of Fault:• due to the generator principle low support of the grid with reactive or active power• performance can be enhanced by using a back to back converter for grid coupling
induction generator in it‘ssimplest configuration: squirrel cage inductiongenerator
simulations: Siemens PTD, 2002
Wind Energy Grid Integration 27
0 1 2 5 2 5 0 3 7 5 5 0 0t [ m s e c ]
1
- 2
0
2
- 1
0
- 5
0
5
P [ p . u . ]P [ p . u . ]Q [ p . u . ]Q [ p . u . ]
U ( L 1 _ E , L 2 _ E , L 3 _ E ) [ p . u . ]U ( L 1 _ E , L 2 _ E , L 3 _ E ) [ p . u . ]
I ( L 1 _ E , L 2 _ E , L 3 _ E ) [ p . u . ]I ( L 1 _ E , L 2 _ E , L 3 _ E ) [ p . u . ]
=≈
=≈
ASGL3
Q
3grid
~1/3 P
Double Fed Induction Generator in Case of Fault:• control unit off• rotor short circuited by thyristor crow bar• restoration of grid activities after relaxation of currents• controlled injection of limited reactive power from back to back converter possible
simulations: Siemens PTD, 2002
generatorconcept in regularoperation
~2/3 P
Wind Energy Grid Integration 28
t/s1 ,9 2 ,0 2 ,1 2 ,2 2 ,3 2 ,4 2 ,5 2 ,6 2 ,7
- 1 ,0
- 0 ,5
0 ,0
0 ,5
t /s1 ,9 2 ,0 2 ,1 2 ,2 2 ,3 2 ,4 2 ,5 2 ,6 2 ,7- 2
0
t /s1 ,9 2 ,0 2 ,1 2 ,2 2 ,3 2 ,4 2 ,5 2 ,6 2 ,7
P [M W ]
2 ,0
1 ,0
Q [M v a r ]
U L 1 U L 2 U L 3 [p .u . ]
I L 1 I L 2 I L 3 [M V A ]
0 ,0
+ 2
1 ,0
simulations: Siemens PTD, 2002
=
≈=
≈
SG3
Q grid
P
Synchronous Generator with Converter in Case of Fault:• reactive currents can be controlled injected limited only by cooling• active power is of course limited by the wind speed
generatorconcept in regularoperation
Wind Energy Grid Integration 29
Use of Generators in Wind Energy Converters
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%19
88
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
Year
SG
ASGL
ASG
(new installations)
source: WMEP report 2004
Wind Energy Grid Integration 30
Who talks about problems must not neglect theopportunities of wind energy integration:
• virtual expanding spinning reserve possible for someseconds
• according to the maximum current capabiltiy reactivepower compensation is possible with WEC as add on.
• grid control is possible by control of the injectedreactive power
• active filtering is possibe the same way.
Wind Energy Grid Integration 31
Quelle: (www.emd.dk)
Grid Integration first Step: Choice of the site
Wind Energy Grid Integration 32
Criteria:
•voltage rise
•rise of short circuit power
•voltage change caused byswitching events
•flickers
•harmonics
Grid Integration 2nd Step: check of grid performance
example: island grid Sifnos/Greece
voltage rise at grid nodes
number of grid node
max. allowed due toEN50160
max. allowed due toVDEW standard
conn. grid node
Wind Energy Grid Integration 33
...now available as software modul „eGRID“
for
„WindPro2 - Software forWind Energy Planning and Project Desingn“
Quelle: Erneuerbare Energie, Heft 1, Jg. 2005
INTEGRID – gridcomputation tool of theUniversity of Kassel
Wind Energy Grid Integration 34
Max Load
"Les Saintes" network
TR WTG5
2
TR WTG4
2
TR WTG3
2
TR WTG2
2
TR WTG1
2
TR WTG8
2
TR WTG6
2
TR WTG7
2
TR
311 9
TR
312 9
Zozio Load
Los Santo..
Marigot Load
Anse Mir ..
Anse du B..
Mairie Load
Ans
e R
odr.
.
Fond de c..Fernand LoadChameau L..Sarkis LoadDuplessis..
Felicite Load
Crawen Load
Pentite a..Labas Load
Subsea ca..
Sub
sea
ca..
Z-Mairie-..
Ans
e R
odr.
.
Fond de c..Fernand-F..T-Fernand..
T-F
elic
it..
Centrale-..
Vie
ux-F
or..
Z-Mairie-..
Z-B
ourg
-A..
Z-M
ir-A
ns..
Marigot-L..
Ext Grid
Mor
el-Z
ozio
Mrig
ot-M
orel
Z-M
ir-M
arig
ot
Z-Bourg-Z-Mir
PCC-WTG S..
T-F
elic
e-P
CC
T-R
odrig
u..
Chameneu-..Sarkis-Ch..Duplessis..Cra
wen
-Du.
.
Z-L
abas
-L..
WT
G S
tati.
.Z
-Lab
as-L
..Z
-Lab
as-L
..W
TG
5-W
TG
6..
Z-L
abas
-L..
Z-L
abas
-L..
WT
G5-
WT
G6
WT
G S
tati.
.
Z-L
abas
-P..
PC
C-Z
-Lab
as
0 Ohm(1)
0 Ohm(2)
0 Ohm(3)
0 Ohm(4)
0 Ohm(5)
0 Ohm(6)
0 Ohm(7)
0 Ohm(8)
WTG 1
G~
WTG 2
G~
WTG 3
G~
WTG 4
G~
WTG 5
G~
WTG 6
G~
WTG 7
G~
WTG 8
G~
Load Vieu..
WTG 7/0.4(1)
WTG8/0.4(1)
WTG1/0.4
WTG 2/0.4
WTG 3/0.4
WTG4/0.4
WTG 5/0.4
WTG 6/0.4
WTG1/0.4(1)
WTG 2/0.4(1)
WTG 3/0.4(1)
WTG4/0.4(1)
WTG 5/0.4(1)
WTG 6/0.4(1)
WTG 7/0.4
WTG8/0.4
Z-Labas
T-Felicite
Felicite
Anse Mir
Las Santos
Zozio
Morel
Marigot
Z-Mir
Z-Bourg
WTG 4/20
WTG 3/20
WTG2/20
WTG1/20
Z-Mairie
WTG 8/20
WTG 7/20
WTG6/20
WTG 5/20
WTG Station
PCC
Mairie
Anse du Bour..
T-Rodrigue
Centrale
Crawen
Les Saintes
Vieux-Fort
Grid 63 kV
Sar
kis
Cha
mea
u
T-F
erna
nd
Fer
nand
Fo
nd
de
cu
re
Anse
Rod
rigu.
.
Dup
less
is
LabasPetite anse
DIg
SIL
EN
T
...for Grid Analysis
Wind Energy Grid Integration 35
Example for 4 scenarios:
being analyzed here:
1. Change of magnitude and direction for active and reactive power
2. Power and voltage losses3. Reactive power compensation needs4. Thermal and other physical overload margin
...for Power Flow Analysis (with and w/o wind farms) for varying load conditions
Wind Energy Grid Integration 36
´´
maxmax 1.1
k
WTni
S
Pku
⋅⋅
⋅=∆λ
...for changes due to switching events
Wind Energy Grid Integration 37
...for calculation of yield, noise, revenue etc. togetherwith the EMD program system
Energi- og Miljødata
Wind Energy Grid Integration 38
Additionally to software tools IEE/EVS and ISET implemented medium voltage grid hardware simulatorfor physical evaluation of solutions
Wind Energy Grid Integration 39
Simulator for medium voltage grid hardware to validatetheoretical approaches for integration of WEC‘s
Wind Energy Grid Integration 40
Off-shore Wind Farms Being Discussed and Planned
When these projectsbecome reality, verybig installations haveto be connected to the high voltage gridon shore!
The question is:What are the impacts?
Wind Energy Grid Integration 41
20.000-25.000 MW2011 – 20304. further extensions
2.000-3.000 MW2007 – 20103. 1st extension
min. 500 MW2004 – 20062. start up
0 MW2001 – 20031. preparing phase
poss. capacitydurationPhase
How Will these Power Flows Interact with the On-Shore Grid?
Wind Energy Grid Integration 42
Windgeschwindigkeit
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/sec
)
W(m/sec)
Deutsches
Verbundnetz
station 1
station N
Windpark 1
seacables
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/se
c)
Windgeschwindigkeit
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/sec
)
W(m/sec)
Wind byDWD
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/se
c)
±QEin(t)
Wind byDWD
wind farm N
U21(t) U22(t)
±QAus(t)
∆P(t), ± ∆Q(t), ∆U(t)
PEin(t)
PAus(t) ±QAus(t)
PnEin(t)
results forPCC:PAus(t)
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
P(t)
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
P(t
)
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
P(t
)
PEin(t)
needs?
dispatcherNo control of WEC‘s and wind farms
direction of computations UPCC(t)
...uncontrolled coupling of off shore wind farms
Wind Energy Grid Integration 43
Windgeschwindigkeit
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/sec
)
W(m/sec)
Deutsches
Verbundnetz
station 1
station N
wind farm 1
sea cables
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/se
c)
Windgeschwindigkeit
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/sec
)
W(m/sec)
Wind byDWD
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
W(m
/se
c)
±QEin(t)
Wind byDWD
wind farm N
±QAus(t) – max. allow. value
∆P(t), ± ∆Q(t), ∆U(t)
PEin(t)
PAus(t) ±QAus(t)
PnEin(t) Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
P(t)
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
P(t
)
Wirkleistung
0
2
4
6
8
10
12
14
16
18
1 2 3 4 5 6 7 8 9 10
t
P(t
)
PEin(t)
needs?
dispatcher
direction for computation
control possible: targetdata for WEC‘s and wind farms aregenerated
Input for calculation set forPCC:PAus(t) – max. allow value
...and controlled coupling of off shore wind farms
Wind Energy Grid Integration 44
0.0 5.0 10.0 15.0 20.0
-100 mHz
-400 mHz
-200 mHz
-300 mHz
100 mHz
0 mHzE.ON E.ON gridgrid codecode implementedimplemented sincesince 01.08.200301.08.2003
old old standardsstandards usedused
t [sec]
Simulation of grid frequency after a 3-phase fault in the 380kV grid with implemented E.ON Grid code and without (assumption 2005)
source: E.ON Netz GmbH
Wind Energy Grid Integration 45
visit us at http://www.DISPOWER.org
Wind Energy Grid Integration 46Quelle: (www.emd.dk)
Advanced Grid Control for Distributed Generation Integration into the Grid using the Converters itself
• Implementation of new communication devices and protocols
• Improvement of the decentralised measurement data acquisition
and control hardware (modular PLC devices)
• Programming of improved GCU software with advanced grid control
algorithms
• Tests and demonstration of the improved GCU system at the site
Friedland-Deiderode
One of the German test sites:
Wind Energy Grid Integration 47
measurmentprocessing unit
MV gridi. e. 20kV, 50Hz, 3~
u, itransducer
measurement dataP, Q, U, etc.
U I
Control andof the wind energy
converter
WECcontrol
Field Control Level
Control and parameter settings
dispatcher
data acquisition & messagesGrid Control Level
data transmission &configuration
Grid Control Unit (GCU)CPU
Site Control Level
grid status
The Idea: Using Inverter Power Capacity to Control the Grid Voltage, the Principle:
Wind Energy Grid Integration 48
Example of Data Acquisition for the GCU-Systems at Deiderode
-20..+20mA
-20..+20mA -20..+20mA -20..+20mA-20..+20mA-20..+20mA
3~ 3~ 3~
WTG Enercon E30(200 kW)
WTG AN Bonus 44-3(600 kW)
WTG AN Bonus 44-3(600 kW)
WTG Enercon E40(500 kW)
CHP “Mülldeponie”(2*440 kW)
P, Q, UL1-L2 P, Q, UL1-L2 P, Q, UL1-L2P, Q, UL1-L2
PLC
#3
P, Q, UL1-L2
PLC
#2
PLC
#4
PLC
#5
PLC
#6
PLC
#1
U ,
U ,
U
L1-L2
L2-L3
L3-L1
Ethernet
e.g. Ethernet
Substation (SST) Friedland
3~ /20kV /50 Hz
Trafo Substation “UW Grone”
Data transmission via radio connection (e.g. W-LAN)
Ethernet Ethernet Ethernet Ethernet
ModemRS 232
Remote control by Power Dispatch Centre
Distance: 1200 m Distance: 230 m Distance: 210 m Distance: 180 m
Dis
tan
ce:
3700
m
Advanced
Grid-Control-Unit
Main Controller
PC
3~3~
HV-Systeme.g. 110kV, 50Hz, 3~
U I
-20..+20mA P,Q,UL1-L2
P
t
P
t
P
t
P
t
P
t
Wind Energy Grid Integration 49
Remote Data Acquisition for the GCU-Systems at Deiderode
Wind Energy Grid Integration 50
BHKW "Mülldeponie" - Generator 1; 5.10.2000
-50
0
50
100
150
200
250
300
350
14:11:00 14:12:00 14:13:00 14:14:00 14:15:00 14:16:00 14:17:00 14:18:00 14:19:00 14:20:00
Uhrzeit
Wir
klei
stu
ng
[kW
]; B
lin
dle
istu
ng
[kV
Ar]
395
396
397
398
399
400
401
402
403
Net
zsp
ann
un
g [
Vo
lt]
P - Gen.1
Q - Gen.1
U12
... and it works really surprisingly good: grid voltage followsthe injected reactive power
similar installations together with I.T.E.R. can be found at Teneriffe and La Palma
Wind Energy Grid Integration 51
This way the statement is:
• Ongoing integration of wind power will change the gridsituation,...
• but wind energy converters with power electronicinverters itself can potentially act to
increase short circuit power
control grid voltage level
compensate reactive power of loads
compensate harmonics
The crucial point is: To exploit this potential!
Wind Energy Grid Integration 52