Vindkraft i kraftsystemet

Transcription

Vindkraft i kraftsystemet
Kjetil Uhlen og John Olav G. Tande
SINTEF Energiforskning
[email protected]
[email protected]
SINTEF Energiforskning AS
1
Oversikt




Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
 Balansehåndtering
 Energi- og effektbidrag
 Storskala offshore vindkraft - systemkonsekvenser
2
Norwegian wind energy potential
 Very good wind conditions – wind farms may
produce +3000 full load hours
 Theoretical potential +1000 TWh/year
(annual el consumption in Norway ~120 TWh)
 Official target is 3 TWh annual wind energy
production by year 2010
 Development is ongoing:
320 MW (~1 TWh) was installed by mid 2006;
+15 TWh is in planning
 Financial support is low: 0.08 NOK/kWh and
probably not sufficient for many projects
 A realistic goal for wind energy use in Norway
is 20 TWh by 2020 (on land and offshore)
 Norway has also a potential for developing a
wind industry – especially related to deep sea
offshore technology.
Smøla 150 MW wind farm
3
Oversikt

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Vindkraftteknologi
Systemutfordringer
Eksempler:
4
From wind turbines to wind power plants
 1980’s:
 typical wind turbine size 50 - 300 kW
 few installations – marginal influence on distribution grids
 grid connection was allowed using simple rule of thumbs
 1990’s:
 typical wind turbine size 300 – 1500 kW
 more and larger installations – significant impact on voltage quality
 national guidelines suggest limits for flicker emission etc, and that WTs
shall stop in case grid conditions outside 0,9<U<1,1 pu and 48<f<52 Hz
 IEC 61400-21 (ed 1 – 2001) gives basis for rational assessment of impact
on voltage quality of wind turbines in distribution grids
 2000’s:
 typical wind turbine size is in MW’s
 large wind farms constitute significant part of power system
 grid codes require wind farms to ride-through temporary grid faults, and
also support voltage and frequency control
 wind farms are becoming power plants - IEC 61400-21 is updated
accordingly to facilitate power quality test on modern wind turbines
5
Teknologi - Vindkraftverk
Foto: Hydro
 Horisontalakslede (tre-bladede) vindturbiner for
kraftproduksjon
 Elektromekaniske konfigurasjoner
 Regulering
6
Main types of wind turbine technologies
Fixed speed, stall/pitch
Gear box
Control system
Variable slip
Gear box
Control system
IG
Doubly-fed induction generator
Gear box
Control
system
DFIG
~
~
Full converter, gear/no gear
Gear box
Control system
G
~
~
Total wind technology market ~ EUR 12 billion (2005)
Top 5 manufacturers: Vestas, Enercon, Gamesa, GE, Simens
7
Major wind turbine manufacturers
 Vestas (DK)
 Opti-slip and Opti-speed
 NTE: Vikna og Hundhammerfjellet
 SIEMENS-BONUS (DK)
 Traditional AG/active stall
 Statkraft: Smøla (150 MW), Hitra (55 MW) and Kjøllefjord
 Enercon (DE)
 Multi-pole synchronous generator, direct drive
 TE: Valsneset and Bessakerfjellet
 Nordex (DE)
 DFIG
 Havøygavlen: 16 x 2.5 MW
 GE wind (USA)
 DFIG og frequency converter
 ScanWind (N)
 NTE: Hundhammerfjellet
8
Slik kan de se ut..
Her mangler det et bilde av
en ”konvensjonell”
vindturbingenerator
Vestas V80-2MW nacelle
Stator i Enercons 4.5 MW
9
Oversikt
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Vindkraftteknologi
Systemutfordringer
Eksempler:
10
Reguleringsformål
 Maksimal utnyttelse av tilgjengelig
vindenergi
 Følge driftsoptimum.
 Redusere belastninger
 Aktiv demping av mekaniske svingemodi.
 Bidra i systemsammenheng
 Effekt, frekvens og spenningsregulering
11
Regulering av vindkraftverk
 Hensikt:
 Optimalisering av elproduksjon
 Effektbegrensning
 Redusere effektfluktuasjoner og mekaniske påkjenninger, pga:
 Hurtige vindvariasjoner
 Strukturelle modi, 3P-variasjoner, osv.
 (Forstyrrelser fra nettet)
 Overholde krav til elkvalitet
 Dempe effekten av hurtige vindvariasjoner på spenning.
 Redusere flimmer
 Reaktiv støtte / spenningsregulering
12
Additional wind farm controls
 Control of power output from wind farm.
 Setpoint control within the available power range
 Frequency and voltage control
 Control functionality enabling wind farms to
contribute with primary active and reactive
reserves
13
Available power
Power
Power
Modern wind farm control
droop
Set-point power
Available power
Reserve power
Frequency
Reactive power
Power
Time
Time
droop
Voltage
14
Energi og effekt i vinden
Turbineffekt:
Pwind
1
3
 C p air Arotor v wind
2
www.windpower.org
Betz-Lanchester:
v1
3
For en ideell rotor Cpmax=0.59 hvis
v2
 Typiske verdier for effektkoeffisient for trebladede vindmøller
ligger i dag omkring Cp=0.5.
 Effektfaktoren er avhenging av: - Antall blader i rotor.
- Blad – design.
15
Regulering av vindkraftverk
Effektregulering
 Mulighetene avhenger av systemkonfigurasjon
(turbin og el-konverteringssystem)
 Prinsipper for effektregulering:
 ”Stall”
 ”Pitch”
 Turtall
 Vha. frekvensomformer
 Vha. asynkrongenerator og variabel sakking
 ”Yaw”
16
b
PW
vw
w
Pel
Gearbox
Nett
f1
f2
Turbineffekt:
PW = ½ Cp(l ,b ) A vw3
,”Tip speed ratio”
l = w r / vw
- Turtall
- Pitch
- Yaw
17
Effektregulering
Variabelt turtall
 Begrensninger i pitch-regulering knyttet til hastighet
(båndbredde) og ytelse.
 Ved å regulere turtall oppnås:
 Ytterligere optimalisering av virkningsgrad.
 Kan utnytte energien i roterende masser (korttids energilager).
 Hurtigere og nøyaktigere regulering
 Turtallsregulering kan implementeres på ulike måter
 vha. asynkrongenerator med variabel sakking
 vha. dobbeltmatet asynkrongenerator
 vha. full frekvensomformer (uavhengig av generator)
18
Oversikt
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Vindkraftteknologi
Systemutfordringer
Eksempler:
19
Hva er systemutfordringene?
(Økonomi og pålitelighet)
 Driftssikkerhet
 Risiko mht utfall/blackouts (pålitelighet, spenningskvalitet)
 Overvåking og kontroll i drift
 Tekniske og funksjonsmessige krav til anlegg som tilknyttes nettet
 Effektbalanse
 Risiko for effektsvikt (rasjonering, osv.)
 Driftsplanlegging
 Energiplanlegging
 Risiko for energimangel (høye priser)
 Langsiktig planlegging og investering i nett og produksjon
20
21
Exchange capacity (MW)
100 MW
740 MW
1200 MW
1600 MW
200 MW
NORWAY
FINLAND
500 MW
2000 MW
SWEDEN
500 MW=
1050 MW=
740 MW=
270 MW=
1350 MW
350 MW=
EST
DENMARK
600 MW=
700 MW=
NED
<1200 MW 600 MW= 600 MW=
POL
GER
22
Current challenges
Source: Statnett
Large scale integration of
renewable energy:
•
Positive contribution to the
energy balance
•
Main challenges:
– Market solutions
– Bottlenecks and
transmission capacity
– Voltage and frequency
control and support
– Failure tolerance and
protection (FRT)
– Reactive power support
23
Hva skiller vindkraftverk fra andre kraftverk?
Aktiv effekt
Frekvens
Spenning
Reaktiv effekt
Energi input:
-Brensel
-Magasin
G
Nett
Aktiv effekt
Frekvens
Spenning
Reaktiv effekt
Energi input:
-Vind
vw
G
Nett
 Vindkraftverk mangler energilager ”bak” turbinen
 Vanskeliggjør produksjonsplanlegging
24
Uregulert produksjon?
 Begrep fra vannkraft
 Kraftverk med liten eller ingen magasinkapasitet (elvekraft)
 Karakterisert ved
 at kraften må produseres når det er tilsig
 mindre frihetsgrader mht produksjonsplanlegging
 Definisjonen passer også godt for vindkraft
 Og i noen grad for kombinerte kraft- og varmeverk (CHP)
 Uregulert kraft betyr
 at energitilgangen er variabel og ikke fullt styrbar
 Ikke at produksjonen er uforutsigbar
25
Annual and seasonal wind generation
(% of annual)
Normalised annual production (%)
140
7
120
6
100
5
80
4
60
3
Wind
Hydro
40
Wind Power
Hydro inflow
Consumption
2
1
20
0
0
1960
1965
1970
1975
Year
1980
1985
1990
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52
Week of year
Wind and hydro – a win-win case:
Combining wind and hydro provides for a more stable annual energy supply
than hydro alone, and wind generation will generally be higher in the winter
period than in the summer.
26
Hour by hour variations of wind generation
Std of delta wind power (pu)
0.25
Estimate
Observation
0.2
0.15
0.1
0.05
0
0
5
10
# of sites
15
20
Wind impact on need for balancing power:
10 % wind energy supply of gross demand in the Nordic power system
gives an extra balancing power of 1.5%-4% of the installed wind capacity,
corresponding to a cost of about 0,8 øre per kWh wind, and about half if
investment in new reserve capacity is not needed. [Holttinen 2005]
27
Capacity
Capacity value (%)
20
10
Wind capacity value
0
200
400
600
Installed wind power (MW)
c)
800
1000
40
Simple scaling of wind production
Summation of three wind farms
30
20
10
0
2
4
6
8
10
Penetration level (%)
12
14
Wind capacity value = average generation at low penetration
The smoothing effect of distributed wind is significant
28
Wind generation impact on power system
 Wind will replace the generation
with the highest operating cost,
and reduce the average Nord
Pool spot market price.
 20 TWh/y wind generation will
reduce the average system price
with about 3 øre/kWh and CO2
emissions by 12-14 million tons
per year for the case of replacing
coal, and about 6 million tons per
year for replacing natural gas.
 Replacing gas turbines on oilrigs
with wind generation would give
higher savings of CO2 and NOx
emissions.
NOK/MWh
Demand (buy)
Supply (sale)
System price
MWh
Volume
29
Oversikt

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Vindkraftteknologi
Systemutfordringer
Eksempler:
30
Example related to congestion management and
balancing control in Nordel

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Frequency control reserves
Balancing control
Congestion management
Reserves
 Illustrating Nordic collaboration and sharing of reserves
across synchronous interconnections (UCTENordel)
 Example is from 8. January 2005
 nearly 2000 MW wind power disconnected due to severe storm in
Southern Scandinavia
31
Denmark West
MW
GWh
Central power plants
3,516
16,161
Decentralised CHP units
1,567
6,839
Decentralised wind turbines
2,374
4,363
Offshore wind farm Horns Rev A
160
Consumption
21,043
Maximum load
3,780
Minimum load
1,246
Capacity export to UCTE
1,200
Capacity import from UCTE
800
Capacity export to Nordel
1,560
Capacity import from Nordel
1,610
Key counts of the power system of Eltra for the year 2003
(Source: Energinet.dk)
32
Elspot areas and transmission capacities
NO3
NO2
NO1
1000 MW
FI
SE
950 MW
DK1
DK2
1200 MW
800 MW
To Germany
33
NO2
Real life case – balance handling
 At 8 January 2005 a strong storm crossed
over Denmark
 The wind farms of western Denmark at first
produced close to rated power, but then
started to cut out due to the excessive wind
speed (+ 25 m/s) – the wind production were
reduced from about 2200 MW to 200 MW in
a matter of 10 hours
Data for DK1, west Denmark 2003
+/-1000 MW
670/630 MW
SE
MW
Central power plants
3,516
Decentralised CHP units
1,567
Decentralised wind turbines
2,374
Offshore wind farm Horns Rev A
NO1
DK1
DK2
160
Maximum load
3,780
Minimum load
1,246
Germany
800/1200 MW
34
8 January 2005
2500
2250
2000
MWh/h
1750
1500
1250
1000
750
500
250
0
-250
Exchange DK1 -> NO1
-500
-750
Balancing power (NO1)
Windpower DK1
-1000
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
Source: NORDPOOL
The case demonstrates that the existing marked based mechanisms can
handle large variations in (wind) generation and demand
35
Oversikt

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Vindkraftteknologi
Systemutfordringer
Eksempler:
36
Wind impact on system adequacy - Case study
Total import capacity
14 TWh / 1600 MW (4x400 MW)
13 TWh hydro / 2250 MW (6x375 MW)
0,18 TWh wind / 62 MW (3 wind farms)
18 TWh annual load / 3180 MW max load
Increasing to 21 TWh / 3780 MW
Options
 A: 3 TWh wind / 1000 MW (3 wind farms)
 B: 3 TWh gas / 375 MW
 C: 3 TWh wind + 3 TWh gas
37
Normal year load and generation
35000
GWh
30000
25000
Import
20000
Gas
Wind
15000
Hydro
10000
Load
5000
0
Base (1.0 %)
A (15.2 %)
B (0.9 %)
C (15.2 %)
38
Base case 30 years week by week import
(result of Multi-Area Power Market Simulation)
Import per week (GWh)
400
300
200
100
0
-100
-200
-300
1
6
11
16
21
26
31
36
41
46
51
Week of year
39
Cumulative distribution of weekly import
100
90
CDF of import (%)
80
70
Base
Case A
Case B
Case C
60
50
40
30
20
10
0
-400
-200
0
200
400
Import per week (GWh)
40
Annual variations in import
10000
Import (GWh)
8000
6000
Base
Case A
Case B
Case C
4000
2000
0
-2000
-4000
1961 1966 1971 1976 1981 1986
Year
Wind and gas contributes equally to the energy balance
41
Case study max load and generating capacity
6000
5000
Wind
4000
MW
Gas
3000
Import
Hydro
2000
Max load
1000
0
Base
A
B
C
42
Loss of load probability (LOLP)
LOLP is here probability of exceeding N-1 criterion
Capacity value = load carrying capacity
LOLP (%)
Wind capacity value (%)
Gas capacity value (%)
Wind penetration (%)
Base
0.11
31.5
1.0
A
7.2
14.7
15.2
B
1.43
34.3
95.2
0.9
C
0.35
13.6
94.7
15.2
Without new generation in case A, B and C the LOLP=26%
43
Oversikt

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Vindkraftteknologi
Systemutfordringer
Eksempler:
44
Integration of large-scale offshore
wind power in the Norwegian power
system
Magnus Korpås, Thomas Trötscher,
John Olav Giæver Tande
SINTEF Energy Research
[email protected]
45
Project: Deep sea offshore wind power

Installation at deep sea far from shore:

Unlimited potential and high energy output
 Minimized negative environmental impact

Challenges:

Bigger, lightweight and strong wind turbines
Foundation / floater
 Grid connection (AC, HVDC, multi-terminal)
 Grid connection and power system
integration
HYWIND
46
25 TWh/y wind generation for
supply to oilrigs, mainland grid
and trans-national connections
Floating offshore wind turbines –
a sustainable energy future
 Use Norwegian oil and gas industry know-how.
 Large scale commercial use of floating offshore wind turbines is
viable by year 2020.
 The market is global.
 Hot political subject in Norway.
47
Simulation study
 5 simulation cases describing possible situations in
2025:
 A: 10 TWh load increase
 B: …added 25+10 TWh offshore+onshore wind
 C: …added 20 TWh new hydro
 D: …added new wind in DE and DK
 E: …added 3200 MW new exchange capacity
48
Wind data
Normalised production [p.u.]
1
MYKEN
66 oN
NORDØYAN FYR
63 o
N
ONA II
KRÅKENES
60oN
UTSIRA FYR
0.6
0.4
0.2
0
LISTA FYR
3 oE
6o
E
o
9 E
o
12 E
1000
o
2000
3000
4000
5000
Duration [hours]
6000
7000
8000
15 E
1
LISTA FYR
UTSIRA FYR
KRÅKENES
ONA II
NORDØYAN FYR
MYKEN
0.8
0.6
p.u. of installed power
57oN
Estimated 5 offshore wind farms, NO
Estimated 5 onshore wind farms, NO
Historical onshore, DK-W
0.8
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
0.5
1
1.5
2
2.5
Hours
3
3.5
4
4
x 10
49
Power market model
50
Wind impact on hydro reservoir
B: Added 25+10 TWh wind
100
100
90
90
80
80
70
70
Reservoir level [%]
Reservoir level [%]
A: 10 TWh load increase
60
50
40
30
60
50
40
30
20
20
10
10
0
1000
2000
3000
4000
5000
Time [hours]
6000
7000
8000
0
1000
2000
3000
4000
5000
Time [hours]
6000
7000
8000
Median
Median 2005 reference
51
Wind impact on prices
Wind reduces winter price peaks in dry years
1400
Reference case
Case A: 15 TWh load increase
Case B: Added 35 TWh wind
NO price [NOK/MWh]
1200
1000
800
600
400
200
0
2
4
6
8
10
12
14
Hydro inflow year
16
18
20
22
52
Wind impact on prices
1400
A
B
C
D
E
NO price [NOK/MWh]
1200
1000
800
load increase
add wind in NO
add hydro in NO
add wind in DE+DK
3200MW new HVDC
600
400
200
0
0
10
20
30
40
50
60
Duration [%]
70
80
90
100
Hours with zero price caused by full hydro reservoirs
53
Wind impact on power exchange
A
B
C
D
E
Net export from Norway [TWh/yr]
60
50
40
30
20
10
0
-10
-20
-30
2
4
6
8
10
12
14
Hydro inflow year
16
18
20
54
Conclusions
 Deep sea offshore wind power has very high potential in Norway
 Unlimited areas
 Very high wind speeds
 Wind power relieves constrained energy situations in winter
 Adding 25 TWh offshore wind, 10 TWh onshore wind and 20 TWh
hydro is a plausible scenario
 Exchange capacity should be increased to avoid hydro spillage
55
Further work
 Include year-to-year variations in wind speed
 Increase number of price areas
 Further tuning of water-value calcualtions
 Analysis and optimization of offshore grid layout
56
MYKEN
6 6 oN
NORDØYAN FYR
6 3 oN
ONA II
KRÅKENES
6 0oN
UTSIRA FYR
LISTA FYR
5 7o
N
3 oE
6 oE
9oE
o
12 E
o
15 E
57
Normalised production [p.u.]
1
Estimated 5 offshore wind farms, NO
Estimated 5 onshore wind farms, NO
Historical onshore, DK-W
0.8
0.6
0.4
0.2
0
1000
2000
3000
4000
5000
Duration [hours]
6000
7000
8000
58
1
LISTA FYR
UTSIRA FYR
KRÅKENES
ONA II
NORDØYAN FYR
MYKEN
0.8
p.u. of installed power
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
0.5
1
1.5
2
2.5
3
3.5
Hours
4
4
x 10
59
Summing up:
 Wind generation impact on power system operation and adequacy will be
overall positive. Wind contributes with energy and capacity value.
 Combining wind and hydro provides for a more stable annual energy supply
than hydro alone, and wind generation will generally be higher in the winter
period than in the summer.
 Wind impact on the need for additional balancing power is moderate, i.e. the
extra balancing cost is about 0,8 øre per kWh wind, and about half if
investment in new reserve capacity is not needed.
 The real life example from 8 January 2005 demonstrates that existing market
based mechanisms can handle large amounts of wind power
 Wind power has a capacity value starting from average power and decreasing
at high penetration
 35 TWh wind will reduce the average spot market price with about 5-8
øre/kWh.
 Wind generation is a cost-effective means to reduce emissions of greenhouse
gasses
Impact of integrating wind power in the Norwegian power system
SINTEF Energy Research, April 2006, TR A6337. www.sintef.no/wind
60
Nordic power system
 Power system (see www.nordel.org):
 Synchronous Nordic interconnection: Norway, Sweden, Finland and
Denmark East
 Denmark West is synchronously connected to UCTE
 Iceland
 Main players:
 Power exchange: NordPool
 TSOs: Statnett (NO), SvK (SE), Fingrid (FI) and Energinet.dk
 DNOs, generators, consumers, traders, etc.
61
Nordic power system
 Markets and services (see www.nordpool.com):



Financial market and clearing services
Hourly day-ahead market: ELSPOT
Intra-day market ELBAS (individual hours, up to one hour prior to delivery):

Intra-hour/real-time balancing market: RK (Regulating power market)

Operated by the TSOs
 Some characteristics of the Nordic power system (that motivates present ancillary
services):





Strong and weak grids, long distance interconnections,
many players,
distributed generation,
high share of hydro power,
close cooperation.
62
Key figures for 2006
Population
Total consumption
Maximum load1
Electricity generation
mill.
TWh
GW
TWh
Nordel DK
Fin
Icel.
Nor
Swe
24.8
405.4
66.8
393.9
5.4
36.4
6.3
43.3
5.3
90.1
14.2
78.6
0.3
9.9
1.1
9.9
4.7
122.6
19.9
121.7
9.1
146.4
25.4
140.3
0
86
14
-
14
28
58
0
-
73
0
27
98
1
1
-
44
46
9
1
-
Breakdown of electricity generation:
Hydropower
Nuclear power
Other thermal power
Wind power
Geothermal power
%
%
%
%
%
1) Measured 3rd Wednesday in January
51
22
24
3
-
- = Data are non-existent
0 = Less than 0,5 %
63
Source: Nordel
Generation capacity in Nordel (GW)
27.6
16.2
NORWAY
10.8
2.6 2.9
9.5
0.6 0.3
5.0
9.2
0.1
FINLAND
0.5
3,1
Conv. thermal
Nuclear
Hydro
Wind
SWEDEN
DENMARK
64
Electricity Generation in Nordel 2006 (TWh)
120
46
64 62
22
NORWAY
11
1 1
37
FINLAND
13
6
1
Conv. thermal
Nuclear
Hydro
Wind
SWEDEN
DENMARK
65
Floating offshore wind turbines
 Installation at deep sea far from shore:
 Unlimited potential and high energy output
 Minimized negative environmental impact
 Cost competitive renewable generation
 Challenges:
 Bigger, lightweight and strong wind turbines
(10 MW, 160 m wingspan ~ twice a jumbo jet)
 Develop floater (design, installation, O&M)
 Power system integration of large scale wind
HYWIND
 Key Norwegian industry stake-holders:
 ScanWind; large wind turbines
 Hydro and Sway; floater concept
 Aker Kværner, Nexans, Devold AMT, Umoe
Ryving etc; sub-supplies of components
 Statkraft etc; wind farm developers
66
Power control
“Pitch” versus “stall” and speed control
b
PW
vw
w
Gearbox
Pel
AG
Nett
fn
 Power is a function of torque and speed: P = T · w
 Turbine speed is determined by grid frequency, gear ratio and slip of
induction generator.
 ”STALL”: Passive torque regulation, determined by the turbine’s
aerodynamic properties.
 ”PITCH”: Active torque control through pitching of rotor blades
(applied for both optimization and power output limitation)
67
Effektregulering
”Stall” og ”Pitch”
b
PW
vw
w
Gearbox
Pel
AG
Nett
fn
 Turtall gitt av nettfrekvens, giromsetning og sakking i
asynkrongenerator.
 ”STALL”: Passiv effektregulering, gitt av turbinens aerodynamiske
karakteristikk.
 ”PITCH”: Aktiv effektstyring gjennom regulering av bladvinkel.
Benyttes for optimalisering og effektbegrensning
68
Regulering av mekanisk moment
Pitch/Stall
www.windpower.org
Source: Lubosny
69
Power control
“Pitch” versus “stall” and speed control
www.windpower.org
Source: Lubosny
70
Power versus windspeed curves
120
Pitch regulated
100
Power (%)
80
Stall regulated
60
40
20
0
0
5
10
15
20
25
30
Wind speed (m/s)
71
Conventional pitch control
25
Pitch angle [degrees]
20
15
3000 kW
2500 kW
2000 kW
1500 kW
1000 kW
500 kW
0 kW
10
5
0
-5
-10
Power limitation
Optimisation
-15
0
5
10
15
20
25
Windspeed [m/s]
72
Active stall control
25
Pitch angle [degrees]
20
15
3000 kW
2500 kW
2000 kW
1500 kW
1000 kW
500 kW
0 kW
10
5
0
-5
-10
Power limitation
Optimisation
-15
0
5
10
15
20
25
Windspeed [m/s]
73

Vindkraft i kraftsystemet

Transcription

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