vindkraft i kraftsystemet
TRANSCRIPT
SINTEF Energiforskning AS 1
Vindkraft i kraftsystemet
Kjetil Uhlen og John Olav G. Tande
SINTEF Energiforskning
SINTEF Energiforskning AS 2
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 3
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
SINTEF Energiforskning AS 4
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 5
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
SINTEF Energiforskning AS 6
Teknologi - Vindkraftverk
Horisontalakslede (tre-bladede) vindturbiner for kraftproduksjon Elektromekaniske konfigurasjoner
Regulering
Foto: Hydro
SINTEF Energiforskning AS 7
Main types of wind turbine technologies
Fixed speed, stall/pitch
Full converter, gear/no gear
Doubly-fed induction generator
Gear box IG
Control system
Gear box IG
Control system
Gear box G
Control system ~~
Gear box G
Control system ~~
Gear box DFIG
Control
system ~~
Gear box DFIG
Control
system ~~~
~
Variable slip
Gear box
Control system
Gear box
Control system
Total wind technology market ~ EUR 12 billion (2005)
Top 5 manufacturers: Vestas, Enercon, Gamesa, GE, Simens
SINTEF Energiforskning AS 8
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
SINTEF Energiforskning AS 9
Slik kan de se ut..
Stator i Enercons 4.5 MW
Her mangler det et bilde av
en ”konvensjonell”
vindturbingenerator
Vestas V80-2MW nacelle
SINTEF Energiforskning AS 10
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 11
Reguleringsformål
Maksimal utnyttelse av tilgjengelig
vindenergi
Følge driftsoptimum.
Redusere belastninger
Aktiv demping av mekaniske svingemodi.
Bidra i systemsammenheng
Effekt, frekvens og spenningsregulering
SINTEF Energiforskning AS 12
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
SINTEF Energiforskning AS 13
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
SINTEF Energiforskning AS 14
Modern wind farm control
Time
Pow
er
Set-point power
Available power
Frequency
Pow
er
droop
Voltage
Reactive p
ow
er
droop
Time
Reserve power
Available power
Pow
er
SINTEF Energiforskning AS 15
Energi og effekt i vinden
Betz-Lanchester: For en ideell rotor Cpmax=0.59 hvis
31
2 windwind p air rotorP C A v
Turbineffekt:
www.windpower.org
1
2
3v
v
Typiske verdier for effektkoeffisient for trebladede vindmøller
ligger i dag omkring Cp=0.5.
Effektfaktoren er avhenging av: - Antall blader i rotor.
- Blad – design.
SINTEF Energiforskning AS 16
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”
SINTEF Energiforskning AS 17
Turbineffekt:
PW = ½ Cp(l ,b ) A vw3 ,”Tip speed ratio” l = w r / vw
- Turtall
- Pitch
- Yaw
Gear-
box Nett
PW vw
Pel
w f1 f2
b
SINTEF Energiforskning AS 18
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)
SINTEF Energiforskning AS 19
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 20
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
Balansehåndtering
Energiplanlegging Risiko for energimangel (høye priser)
Langsiktig planlegging og investering i nett og produksjon
SINTEF Energiforskning AS 21
SINTEF Energiforskning AS 22
Exchange capacity (MW)
NORWAY
DENMARK
SWEDEN
FINLAND
600 MW= 600 MW= <1200 MW
1050 MW=
1350 MW
740 MW=
270 MW=
500 MW
2000 MW
200 MW
740 MW
600 MW=
1600 MW 1200 MW
100 MW
700 MW=
350 MW=
EST
POL
GER NED
500 MW=
SINTEF Energiforskning AS 23
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
Source: Statnett Current challenges
SINTEF Energiforskning AS 24
Hva skiller vindkraftverk fra andre kraftverk?
Vindkraftverk mangler energilager ”bak” turbinen
Vanskeliggjør produksjonsplanlegging
Nett G Energi input:
-Brensel
-Magasin
Aktiv effekt
Frekvens
Spenning
Reaktiv effekt
Nett vw
G Energi input:
-Vind
Aktiv effekt
Frekvens
Spenning
Reaktiv effekt
SINTEF Energiforskning AS 25
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
SINTEF Energiforskning AS 26
Annual and seasonal wind generation
0
20
40
60
80
100
120
140
1960 1965 1970 1975 1980 1985 1990 Year
Normalised annual production (%)
Wind Hydro
0
1
2
3
4
5
6
7
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 Week of year
(% of annual)
Wind Power
Hydro inflow
Consumption
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.
SINTEF Energiforskning AS 27
0 5 10 15 200
0.05
0.1
0.15
0.2
0.25
# of sites
Std
of
delt
a w
ind
po
wer
(pu
)
Estimate
Observation
Hour by hour variations of wind generation
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]
SINTEF Energiforskning AS 28
Wind capacity value
0 200 400 600 800 10000
50
100
150
Installed wind power (MW)
Ca
pa
city v
alu
e (
MW
) a)
0 200 400 600 800 100010
20
30
40
Installed wind power (MW)
Ca
pa
city v
alu
e (
%) b)
0 2 4 6 8 10 12 1410
20
30
40
Penetration level (%)
Ca
pa
city v
alu
e (
%) c)
Simple scaling of wind production
Summation of three wind farms
Wind capacity value = average generation at low penetration
The smoothing effect of distributed wind is significant
SINTEF Energiforskning AS 29
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.
MWh
NOK/MWh
Supply (sale)Demand (buy)
System price
Volume
SINTEF Energiforskning AS 30
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 31
Example related to congestion management and
balancing control in Nordel
Frequency control reserves
Balancing control
Congestion management
Reserves
Illustrating Nordic collaboration and sharing of reserves across synchronous interconnections (UCTENordel)
Example is from 8. January 2005 nearly 2000 MW wind power disconnected due to severe storm in
Southern Scandinavia
SINTEF Energiforskning AS 32
Denmark West
Key counts of the power system of Eltra for the year 2003
(Source: Energinet.dk)
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
SINTEF Energiforskning AS 33
Elspot areas and transmission capacities
NO1
DK1
SE
NO2 FI
To Germany
DK2
950 MW 1000 MW
800 MW 1200 MW
NO3
SINTEF Energiforskning AS 34
Real life case – balance handling
NO1
DK1SE
NO2FI
Germany
800/1200 MW
DK2
+/-1000 MW
670/630 MW
Data for DK1, west Denmark 2003 MW
Central power plants 3,516
Decentralised CHP units 1,567
Decentralised wind turbines 2,374
Offshore wind farm Horns Rev A 160
Maximum load 3,780
Minimum load 1,246
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
SINTEF Energiforskning AS 35
The case demonstrates that the existing marked based mechanisms can
handle large variations in (wind) generation and demand
8 January 2005
-1000
-750
-500
-250
0
250
500
750
1000
1250
1500
1750
2000
2250
2500
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
MW
h/h
Exchange DK1 -> NO1
Balancing power (NO1)
Windpower DK1
Source: NORDPOOL
SINTEF Energiforskning AS 36
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 37
Wind impact on system adequacy - Case study
18 TWh annual load / 3180 MW max load
Increasing to 21 TWh / 3780 MW
13 TWh hydro / 2250 MW (6x375 MW)
Total import capacity
14 TWh / 1600 MW (4x400 MW)
0,18 TWh wind / 62 MW (3 wind farms)
Options
A: 3 TWh wind / 1000 MW (3 wind farms)
B: 3 TWh gas / 375 MW
C: 3 TWh wind + 3 TWh gas
SINTEF Energiforskning AS 38
Normal year load and generation
0
5000
10000
15000
20000
25000
30000
35000
Base (1.0 %) A (15.2 %) B (0.9 %) C (15.2 %)
GW
h
Import
Gas
Wind
Hydro
Load
SINTEF Energiforskning AS 39
Base case 30 years week by week import
(result of Multi-Area Power Market Simulation)
-300
-200
-100
0
100
200
300
400
1 6 11 16 21 26 31 36 41 46 51
Week of year
Imp
ort
pe
r w
ee
k (
GW
h)
SINTEF Energiforskning AS 40
Cumulative distribution of weekly import
0
10
20
30
40
50
60
70
80
90
100
-400 -200 0 200 400
Import per week (GWh)
CD
F o
f im
po
rt (
%)
Base
Case A
Case B
Case C
SINTEF Energiforskning AS 41
Annual variations in import
-4000
-2000
0
2000
4000
6000
8000
10000
1961 1966 1971 1976 1981 1986
Year
Imp
ort
(G
Wh
)
Base
Case A
Case B
Case C
Wind and gas contributes equally to the energy balance
SINTEF Energiforskning AS 42
Case study max load and generating capacity
0
1000
2000
3000
4000
5000
6000
Base A B C
MW
Wind
Gas
Import
Hydro
Max load
SINTEF Energiforskning AS 43
Loss of load probability (LOLP)
Base A B C
LOLP (%) 0.11 7.2 1.43 0.35
Wind capacity value (%) 31.5 14.7 34.3 13.6
Gas capacity value (%) - - 95.2 94.7
Wind penetration (%) 1.0 15.2 0.9 15.2
Without new generation in case A, B and C the LOLP=26%
LOLP is here probability of exceeding N-1 criterion
Capacity value = load carrying capacity
SINTEF Energiforskning AS 44
Oversikt
Vindkraftteknologi
Styring og kontrollmuligheter
Systemutfordringer
Eksempler:
Balansehåndtering
Energi- og effektbidrag
Storskala offshore vindkraft - systemkonsekvenser
SINTEF Energiforskning AS 45
Integration of large-scale offshore
wind power in the Norwegian power
system
Magnus Korpås, Thomas Trötscher,
John Olav Giæver Tande SINTEF Energy Research
SINTEF Energiforskning AS 46
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
SINTEF Energiforskning AS 47
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.
25 TWh/y wind generation for supply to oilrigs, mainland grid and trans-national connections
Floating offshore wind turbines –
a sustainable energy future
SINTEF Energiforskning AS 48
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
SINTEF Energiforskning AS 49
Wind data
1000 2000 3000 4000 5000 6000 7000 80000
0.2
0.4
0.6
0.8
1
Duration [hours]
Norm
alised p
roduction [
p.u
.]
Estimated 5 offshore wind farms, NO
Estimated 5 onshore wind farms, NO
Historical onshore, DK-W
3oE 6oE 9oE 12oE 15
oE
57oN
60oN
63oN
66oN
LISTA FYR
UTSIRA FYR
KRÅKENES
ONA II
NORDØYAN FYR
MYKEN
0.5 1 1.5 2 2.5 3 3.5 4
x 104
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Hours
p.u
. of
insta
lled p
ow
er
LISTA FYR
UTSIRA FYR
KRÅKENES
ONA II
NORDØYAN FYR
MYKEN
SINTEF Energiforskning AS 50
Power market model
SINTEF Energiforskning AS 51
Wind impact on hydro reservoir
1000 2000 3000 4000 5000 6000 7000 80000
10
20
30
40
50
60
70
80
90
100
Time [hours]
Reserv
oir level [%
]
1000 2000 3000 4000 5000 6000 7000 80000
10
20
30
40
50
60
70
80
90
100
Time [hours]
Reserv
oir level [%
]
A: 10 TWh load increase B: Added 25+10 TWh wind
Median 2005 reference
Median
SINTEF Energiforskning AS 52
Wind impact on prices
2 4 6 8 10 12 14 16 18 20 220
200
400
600
800
1000
1200
1400
Hydro inflow year
NO
price [
NO
K/M
Wh]
Reference case
Case A: 15 TWh load increase
Case B: Added 35 TWh wind
Wind reduces winter price peaks in dry years
SINTEF Energiforskning AS 53
Wind impact on prices
0 10 20 30 40 50 60 70 80 90 1000
200
400
600
800
1000
1200
1400
Duration [%]
NO
price [
NO
K/M
Wh]
A
B
C
D
E
load increase
add wind in NO
add hydro in NO
add wind in DE+DK
3200MW new HVDC
Hours with zero price caused by full hydro reservoirs
SINTEF Energiforskning AS 54
Wind impact on power exchange
2 4 6 8 10 12 14 16 18 20
-30
-20
-10
0
10
20
30
40
50
60
Hydro inflow year
Net
export
fro
m N
orw
ay [
TW
h/y
r]
A B C D E
SINTEF Energiforskning AS 55
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
SINTEF Energiforskning AS 56
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
SINTEF Energiforskning AS 57
3oE 6oE 9oE 12oE 15
oE
57oN
60oN
63oN
66oN
LISTA FYR
UTSIRA FYR
KRÅKENES
ONA II
NORDØYAN FYR
MYKEN
SINTEF Energiforskning AS 58
1000 2000 3000 4000 5000 6000 7000 80000
0.2
0.4
0.6
0.8
1
Duration [hours]
Norm
alised p
roduction [
p.u
.]
Estimated 5 offshore wind farms, NO
Estimated 5 onshore wind farms, NO
Historical onshore, DK-W
SINTEF Energiforskning AS 59
0.5 1 1.5 2 2.5 3 3.5 4
x 104
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Hours
p.u
. of
insta
lled p
ow
er
LISTA FYR
UTSIRA FYR
KRÅKENES
ONA II
NORDØYAN FYR
MYKEN
SINTEF Energiforskning AS 60
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
SINTEF Energiforskning AS 61
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.
SINTEF Energiforskning AS 62
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.
SINTEF Energiforskning AS 63
Key figures for 2006
Nordel DK Fin Icel. Nor Swe
Population mill. 24.8 5.4 5.3 0.3 4.7 9.1
Total consumption TWh 405.4 36.4 90.1 9.9 122.6 146.4
Maximum load1 GW 66.8 6.3 14.2 1.1 19.9 25.4
Electricity generation TWh 393.9 43.3 78.6 9.9 121.7 140.3
Breakdown of electricity generation:
Hydropower % 51 0 14 73 98 44
Nuclear power % 22 - 28 - - 46
Other thermal power % 24 86 58 0 1 9
Wind power % 3 14 0 - 1 1
Geothermal power % - - - 27 - -
1) Measured 3rd Wednesday in January - = Data are non-existent 0 = Less than 0,5 %
Source: Nordel
SINTEF Energiforskning AS 64
Generation capacity in Nordel (GW)
10.8
2.6 2.9
27.6
0.6
NORWAY
DENMARK
SWEDEN
FINLAND 9.2
3,1
5.0
9.5
16.2
0.5 Conv. thermal
Nuclear
Hydro
Wind
0.3
0.1
SINTEF Energiforskning AS 65
Electricity Generation in Nordel 2006 (TWh)
NORWAY
DENMARK
SWEDEN
FINLAND
Conv. thermal
Nuclear
Hydro
Wind
37
6
120
1
13
64 62 46
22 11
1
1
SINTEF Energiforskning AS 66
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
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
HYWIND
SINTEF Energiforskning AS 67
Power control
“Pitch” versus “stall” and speed control
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)
Gear-
box
PW vw
Pel
w Nett
fn
b
AG
SINTEF Energiforskning AS 68
Effektregulering
”Stall” og ”Pitch”
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
Gear-
box
PW vw
Pel
w Nett
fn
b
AG
SINTEF Energiforskning AS 69
Regulering av mekanisk moment Pitch/Stall
Source: Lubosny
www.windpower.org
SINTEF Energiforskning AS 70
Power control
“Pitch” versus “stall” and speed control
Source: Lubosny
www.windpower.org
SINTEF Energiforskning AS 71
Power versus windspeed curves
0
20
40
60
80
100
120
0 5 10 15 20 25 30
Wind speed (m/s)
Po
we
r (%
)
Pitch regulated
Stall regulated
SINTEF Energiforskning AS 72
Conventional pitch control
-15
-10
-5
0
5
10
15
20
25
0 5 10 15 20 25
Windspeed [m/s]
Pit
ch
an
gle
[d
eg
ree
s]
3000 kW
2500 kW
2000 kW
1500 kW
1000 kW
500 kW
0 kW
Power limitationOptimisation
SINTEF Energiforskning AS 73
Active stall control
-15
-10
-5
0
5
10
15
20
25
0 5 10 15 20 25
Windspeed [m/s]
Pit
ch
an
gle
[d
eg
ree
s]
3000 kW
2500 kW
2000 kW
1500 kW
1000 kW
500 kW
0 kW
Power limitationOptimisation