Ancillary services from wind power plants Research results · ancillary service products (research...
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Ancillary services from wind power plantsResearch results
Sørensen, Poul Ejnar; Cutululis, Nicolaos Antonio; Hansen, Anca Daniela; Altin, Müfit; Zeni, Lorenzo;Basit, Abdul
Publication date:2014
Document VersionPeer reviewed version
Link back to DTU Orbit
Citation (APA):Sørensen, P. E. (Author), Cutululis, N. A. (Author), Hansen, A. D. (Author), Altin, M. (Author), Zeni, L. (Author), &Basit, A. (Author). (2014). Ancillary services from wind power plants: Research results. Sound/Visual production(digital)
Ancillary services from wind power plants - Research results
Poul Sørensen, Nicolaos Cutululis, Anca D. Hansen, Müfit Altin, Lorenzo Zeni, Abdul Basit
DTU Wind Energy, Technical University of Denmark
Program outline
Ancillary Services: Research Results From Wind Power Plants
• Definitions and requirements for ancillary service
• Technical capabilities of wind power plants to provide ancillary services - state-of-the-art industry and R&D (simulation based) perspectives
• What are the economic incentives and barriers to providing ancillary services?
• What are the next steps for researchers, developers, system operators and turbine manufacturers to allow further penetration of wind into European grids?
Danish Smart Grid Research Network 2 2014-09-05
DTU Wind Energy, Technical University of Denmark
Definitions of ancillary services
• CIGRÉ report - overview of International Practices – definitions for ancillary services can differ significantly based on
who is using the terms. While some definitions emphasize the importance of ancillary services for system security and reliability, others mention the use of ancillary services to support electricity transfers from generation to load and to maintain power quality
• Some TSOs are including more specific types of ancillary services than others because
– differences in the definitions (above) – some of the required properties of the generation plants are
embedded in conventional power plants using directly grid connected synchronous generators.
– new ancillary service products seem to pop up in power systems with large scale penetration of renewables.
Danish Smart Grid Research Network 3 2014-09-05
DTU Wind Energy, Technical University of Denmark
Requirements for – and types of – ancillary services
• Active power reserves (using ENTSO-E glossary) – Frequency containment reserves (FCR) – Frequency restoration reserves (FRR) – Replacement reserves (RR)
• Properties required to maintain power system stability today (Energinet.dk terminology)
– Short-circuit power – Continuous voltage control – Voltage support during faults – Inertia
• Possible additional ancillary service products (research references) – Fast frequency response (and inertia support) – Synchronising power – Power oscillation damping – Black-start capability
Danish Smart Grid Research Network 4 2014-09-05
DTU Wind Energy, Technical University of Denmark
State of the art technical capabilities in industry
• Horns Rev 2002 (Kristoffersen et.al.) according to first DK technical requirements
– Primary frequency control – Secondary frequency control – Reactive power neutral
• Today +
– Continuous voltage control – Voltage support during faults – “Inertia” under development – verification?
Danish Smart Grid Research Network 5 2014-09-05
Cost and value of ancillary services Nicolaos A. Cutululis – DTU Wind Energy Herning, 26 March 2014
© Juw
i Solar G
mbH
RESERVICES CONSORTIUM www.reservices-project.eu
Sharon Wokke Project Manager European Wind Energy Association Rue d’Arlon 80 1040 Brussels (Belgium) Tel: 0032 2 213 18 39 [email protected]
REserviceS work overview
WP2 System Needs
for AS
WP5 – WP6 Case Studies
WP3 – WP4 Capabilities and Costs
• List of services
• System impacts at large VG penetrations
• Cost structure definition
• Procurement survey
• AS costs of non VG generation
• WP3 Wind – WP4 Solar PV
• Tool: framework of functionalities / at different plant levels
• tech. specifications (GCR etc.)
• Verification of capabilities and costs: industry enquiry
• Impacts of variability and predictability
• Costs estimation
• AS provision in Transmission (frequency) and Distribution (voltage)
• Amounts of services, plant capabilities, system impacts, economic benefits, CBA
• Different system types and sizes
• In challenging SNSP scenarios: high % of wind / solar PV
8 2014-09-05 Danish Smart Grid Research Network
• Results from three case studies: – Ireland – based mainly on the results from several multi-year
research programmes (Facilitation of Renewables and DS3); additional investigation of SS costs
– Iberia – using WILMAR, 6 reg. for ES and 1 for PT; all thermal units represented (no aggregation); some agg. for hydro; VG agg. per region
– Europe – 10 countries around North Sea and Baltic; based on TWENTIES scenarios; focus on cross border sharing of frequency reserves
Transmission case studies
9 2014-09-05 Danish Smart Grid Research Network
Benefit of VG in frequency support (cases have different assumptions)
2014-09-05 Danish Smart Grid Research Network 10
DTU Wind Energy, Technical University of Denmark
EASEWIND
• Long title: – Enhanced Ancillary Services from Wind Power Plants
• Objective
– to develop technical solutions for enabling wind power to have similar power plant characteristics as conventional generation units.
• Funding: ForskEL
• Consortium:
– Vestas Technology R&D – DTU Wind Energy – DTU Compute – AAU IET
Danish Smart Grid Research Network 11 2014-09-05
DTU Wind Energy, Technical University of Denmark
Ancillary services from wind power plants
12
The ancillary services from wind power plants are supported by communication and control at the power plant level.
2014-09-05 Danish Smart Grid Research Network
DTU Wind Energy, Technical University of Denmark
13
Simple generic wind power plant model follows the basic structure of the IEC standard Type IV wind turbine model
includes additional adjustments to reflect the dynamics relevant for active power and grid frequency control capabilities.
Pitchcontroller Aerodynamic Mechanical
model
Staticgenerator
Wind speed(CorWind)
P, Q measurements
P control
Q control
v
vFilter
MPPT Power referenceselection
LVRT
wtWPPCP
Optimal speedreference
Wind speedfilter
filtgen _ω
refgen _ω
filtgen _ω
Estimatedavailable power
filtgen _ω
wtMPPTP
wtrefP
wtmeasP
wtmeasP
wtmeasQ
wtrefQwt
WPPCQ
wtrefP
wtavailableP
Pcmdi
Qcmdi
wtaeroP
wtmeasP
rotω
θ
filtgen _ω
2014-09-05 Danish Smart Grid Research Network
DTU Wind Energy, Technical University of Denmark
Wind speed 0.6pu
Short-term overproduction capability Wind speed 0.93pu Wind speed 1.1pu
Below rated wind speed, the overproduction is followed by recovery period
The higher the wind speed, the shorter the recovery period
The higher the overproduction power: the longer the recovery period and the larger the power underproduction -> frequency stability might
be affected the higher the shaft torque -> high mechanical stress of the turbine
No power recovery needed above rated wind speed
0 5 10 15 20 25 30 35 400.2485
0.249
0.2495 Aerodynamic power [pu]
0 5 10 15 20 25 30 35 40-0.005
0
0.005ωgen - ωrot [pu]
0 5 10 15 20 25 30 35 40-1
0
1
Time [sec]
Pitch Angle [deg]
0 5 10 15 20 25 30 35 400.2
0.25
0.3
Electrical power [pu]
0 5 10 15 20 25 30 35 400.8
0.85
0.9 Rotor Speed [pu]
0 5 10 15 20 25 30 35 400.2
0.25
0.3
0.35
0.4Shaft Torque [pu]
0 5 10 15 20 25 30 35 400.6
0.8
1 Aerodynamic power [pu]
0 5 10 15 20 25 30 35 40-0.06-0.04-0.02
00.02
ωgen - ωrot [pu]
0 5 10 15 20 25 30 35 40-1
0
1
Time [sec]
Pitch Angle [deg]
0 5 10 15 20 25 30 35 400
0.5
1
Electrical power [pu]
0 5 10 15 20 25 30 35 400.70.80.9
11.1 Rotor Speed [pu]
0 5 10 15 20 25 30 35 40-0.5
00.5
11.5 Shaft Torque [pu]
0 5 10 15 20 25 30 35 400.8
1
1.2
Aerodynamic power [pu]
0 5 10 15 20 25 30 35 40
-0.01
0
0.01
ωgen - ωrot [pu]
0 5 10 15 20 25 30 35 4002468
Time [sec]
Pitch Angle [deg]
0 5 10 15 20 25 30 35 400.9
11.11.2
Electrical power [pu]
0 5 10 15 20 25 30 35 400.95
1
1.05 Rotor Speed [pu]
0 5 10 15 20 25 30 35 40
1
1.2
1.4 Shaft Torque [pu]
2014-09-05 Danish Smart Grid Research Network 14
DTU Wind Energy, Technical University of Denmark
15
Wind power plant control architecture
2014-09-05 Danish Smart Grid Research Network
DTU Wind Energy, Technical University of Denmark
Enhanced ancillary services
2014-09-05 Danish Smart Grid Research Network 16
WPP Active or Reactive Power output POD controller
PODQ∆I
P PODP∆
Active Power or Current Magnitude
time
time
IR controllerIRP∆f∆
dtdf /
1pu Grid Frequency
time
P
time
WPP Power Output∆
SP controllerSPP∆δ∆
θ∆
Load Angle
Time
WPP power output
Time
DTU Wind Energy, Technical University of Denmark
WPP Inertial response capability
5 10 15 20 25 30 35 400.98
0.985
0.99
0.995
1
1.005
[pu]
Grid frequency
Without IRWith IR
5 10 15 20 25 30 35 400.2
0.21
0.22
0.23
0.24
0.25
0.26
0.27
0.28
0.29
[pu]
WPP power
5 10 15 20 25 30 35 40
0.856
0.858
0.86
0.862
0.864
0.866
[s]
[pu]
Gen. speed5 10 15 20 25 30 35 40
-1.25
0.00
1.00
2.00
3.00
4.00
5.00
[deg
]
Pitch angle
2014-09-05 Danish Smart Grid Research Network 17
DTU Wind Energy, Technical University of Denmark
WPP synchronise power capability
δ∆
0 5 10 15 20 25 30 35 40350
400
450
500
550Load change
[MW
]
0 5 10 15 20 25 30 35 405
10
15
20Rotor angle deviation
[deg
]
0 5 10 15 20 25 30 35 40340
360
380
400WPP power
Time [s]
[MW
]
Without SPWith SP
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OffshoreDC
2014-09-05 Danish Smart Grid Research Network 19
OffshoreDC
WP 3 – Communication and control in clusters of wind power plants
connected to offshore HVDC grids PhD student: Lorenzo Zeni
OffshoreDC Results – status
L. Zeni et.al. From paper in Cigré session 2014
2014-09-05 Danish Smart Grid Research Network
21
VDC,1
VDC,WPP
VDC,2
P1,Q1 P2,Q2
P,Q P,QSG1 SG2
0.5*Zline 0.5*Zline
PWPP,QWPP
P,Q
Grid 2
Grid 1
VSC1 (w chopper)
VSC2 (w chopper)
Bus 1 Bus 2Bus 3
Investigation on system services provision
Onshore AC voltage control and LVRT
Onshore frequency control and power
oscillation damping
Offshore network control
Important results obtained and lines for future work were drawn.
DC voltage control
OffshoreDC
Two strategies are compared: 1. Communication-based control (with communication delay) 2. Coordinated control mirroring the frequency in DC voltage
2014-09-05 Danish Smart Grid Research Network 22
Frequency support through HVDC P2P example
OffshoreDC On the inertial contribution
2014-09-05 Danish Smart Grid Research Network 23
0 2 4 6 8 100.35
0.4
0.45
0.5
A2
- Pre
f [pu]
0 2 4 6 8 100.35
0.4
0.45
0.5
B2
- Pre
f [pu]
Time [s]
(a)
(b)
(b)
(a)
Power reference to WPP (a) From controller (b) Ramp-limited
Communication
Coordinated control
The initial power support is heavily limited by the ramp limiter (0.1 pu/s): relaxation of this figure?
OffshoreDC Conclusions
• Onshore frequency variations can be mirrored offshore • Hence, WPPs can provide frequency control through
HVDC with communication-less scheme • Fast control actions are inhibited by ramp rate limiters in
the WPP • In a P2P connection, communication-based and
coordinated solutions are equivalent, as far as frequency control and inertial response are concerned
2014-09-05 Danish Smart Grid Research Network 24
25
Consortium and budget
Spain (5) RED ELECTRICA DE ESPAÑA IBERDROLA ITT COMILLAS GAMESA ABB S.A.
Belgium (6) ELIA SYSTEM OPERATOR EWEA CORESO UNIVERSITY LIEGE UNIVERSITY LEUVEN UNIVERSITE LIBRE BRUXELLES
Denmark (3) DONG ENERGY ENERGINET DTU ENERGY
France (2) RTE EDF
United Kingdom (2) ALSTOM GRID UNIVERSITY OF STRATHCLYDE
Germany (3) FRAUNHOFER IWES 50 HzT SIEMENS Wind Power
Italy RSE
Ireland UCD
The Netherlands TENNET Portugal
INESC-PORTO
Norway SINTEF
Total budget: 56.8 M€ EU contribution: 31.8 M€
10 European Member States 1 Associated Country
Danish Smart Grid Research Network
26
Demo 4 - The challenge
Danish Smart Grid Research Network
0° 15° E
60° N
Synchronous Area
2020 2030
MW MW
Continental 21,421 57,685
Nordic 4,924 14,669
GB 13,711 33,601
Ireland 1,419 3,219
2030 map
DTU Wind Energy, Technical University of Denmark
• There must be sufficient primary reserves in the power system synchronous area to replace lost production corresponding to dimensioning fault
• This brings power system from normal state to alert state
• Frequency restoration (secondary / tertiary) reserves will return system to normal state in 15 minutes
• Larger faults (loss of generation) may bring system into disturbed (or emergency) state
• Therefore, maximum 15 minute wind power forecast errors are essential to esure adequacy of primary reserves
Large scale challenge: Adequacy of primary reserves
Danish Smart Grid Research Network 27 2014-09-05
Nordic grid code 2007
Synchronous Area Dimensioning faultt MW
Continental 3,000 Nordic 1,200 GB 1,800 Ireland 500
DTU Wind Energy, Technical University of Denmark
• Result for 2020 indicates that there is sufficient primary reserves with current dimensioning fault to cover offshore wind power variability in the four main European synchronous areas
• Result for 2030 indicates that there is not sufficient primary reserves with current dimensioning fault to cover offshore wind power variability in Continental and GB synchronous areas
• PhD poster (Kaushik Das) on more detailed assessment in EU iTesla project
Upscaling results and conclusion
Danish Smart Grid Research Network 28 2014-09-05
Synchronous Area HWSD HWEP Dimensioning faultt
MW MW MW Continental 4,729 3,933 3,000 Nordic 1096 1082 1,200 GB 4,418 4,440 1,800 Ireland 439 438 500
Synchronous Area HWSD HWEP Dimensioning faultt
MW MW MW Continental 1,661 1,548 3,000 Nordic 480 483 1,200 GB 1,212 1,222 1,800 Ireland 224 224 500
2020
2030
DTU Wind Energy, Technical University of Denmark
Simulation of balancing (Simba)
• Simba idea – Simulation of intra hour balancing
as supplement to day ahead – Uses inputs from “day-ahead
market model” – Main imbalance included today is
from wind • Applications of Simba
– Planning of investment – Assessment of new market
designs (e.g. towards real time) – Assessment of cost / value of
reserves – Assessment of needs for reserve
capacities – Economic optimisation of system
services – Assessment of flexible demand
support to system balancing
Danish Smart Grid Research Network 29 2014-09-05
Import Export
Simulation of Balancing (Simba)
DTU Wind Energy, Technical University of Denmark
CorWind Simulation of wind power fluctuations and forecast errors
Danish Smart Grid Research Network 30 2014-09-05
0
200
400
600
800
1000
1200
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:00
Offs
hore
win
d po
wer
in D
enm
ark
[MW
]
8 November 2020
P_W_RTP_W_DAP_W_HA
DTU Wind Energy, Technical University of Denmark
Modelling chain: Spot market – balancing – automatic frequency control
Danish Smart Grid Research Network 31 2014-09-05
Spot market model
Wind generation patterns model (CorWind)
Balancing model
(Simba)
PWind,DA[1h] PWind,HA[5m] PWind,RT[5m]
Psched,DA[1h] Automatic control model
Pplan,HA[5m]
Power system scenario
DTU Wind Energy, Technical University of Denmark
Automatic Generation Control in a power system with high wind power penetration – Danish case study
32 Danish Smart Grid Research Network
2014-09-05
fnominal
factual BACE PI
controller ∆Pset
pfCHP+ -
PCHP
++
PLOAD
PDCHP
Pexchange
Pwind
∆P
∆f/R
PGEN
-
-
-+
∆PDCHP+
++
+90 MW
-90 MWpfDCHP
∆PCHP
AGC model Model overview
Result: simulated AGC performance
DTU Wind Energy, Technical University of Denmark
Wind Power integration into the Automatic Generation Control of power systems
33 Danish Smart Grid Research Network
2014-09-05
Aggregated Wind Turbine modelSimBa
Frequency droop
Fmeasure
Wind Power Plant
Controller
Pref_WT
Pavailable
Pref
Pmeasure
Active power
Controller
Static Generator
ip_cmd
Pmeasure
AGC
+
+
Pref (freq)
ΔP_WF∆Pset
∆P > dP_avail
|∆P| < |curtailing|
∆P < 0
dPavailable
Curtailing Power
yes
no
yes
yes
no
no
∆P_WF = ∆Pset∆P_CHP = 0
∆P_WF = -1*|curtailing|∆P_CHP = |curtailing| -|∆Pset|
∆P_WF = dP_avail∆P_CHP = ∆Pset - Available
∆P_WF = dP_avail∆P_CHP = 0
Aggregated WPP model Secondary (AGC) dispatch with wind
More details in poster
Abdul Basit
DTU Wind Energy, Technical University of Denmark
Summary and reflections on technical capabilities • WPPs can provide basic ancillary services and replace conventional
power plants • Also possible to provide enhanced ancillary services – emulating
synchronous generators (inertia-like response, power oscillation damping and synchronizing power)
– … but is this the optimal solution in future systems? • Ancillary services can also be provided from HVDC connected WPPs
34 Danish Smart Grid Research Network 2014-09-05
DTU Wind Energy, Technical University of Denmark
Economic incentives and barriers • Incentives:
– Technical requirements for grid connection! – Higher prices for reserves than for power (e.g. low – and even
negative power prices) – Co-generation with other production technologies (ramp support) – Enables higher wind power penetration
• Barriers: – Symmetric (up/down) requirement (Spain – TWENTIES)
• Downwards reserves from WPPs is feasible with high penetration
• … loads are more feasible as upwards reserves – Length (= prediction horizon) of reserve products – Development costs for new products – Additional hardware costs – Verification needs for new products –certification costs
35 Danish Smart Grid Research Network 2014-09-05
DTU Wind Energy, Technical University of Denmark
TPWind Technology Platform New strategic research agenda (SRA) / Market deployment strategy 2014 • Issues – very similar to REserviceS
– Frequency support – Voltage support – System restoration support
• Research priorities – Further development of enhanced wind power capabilities from
wind turbine level up to cluster level, including the related design tools and models;
– Testing and verification of frequency and voltage capabilities, and methods of proving compliance of new solutions for advanced capabilities with Grid Codes and standards;
– Harmonisation, standardisation and interoperability of methods and technologies for delivering ancillary services with wind power.
36 Danish Smart Grid Research Network 2014-09-05
DTU Wind Energy, Technical University of Denmark
Next steps to allow further penetration of wind into European grids? • Researchers
– Propose strategies for ancillary services from wind and other sources to ensure system stability with massive scale wind power
• Special focus on power system security with increasing levels of non-synchronous generation
• Not necessarily emulation of synchronous generators – other smarter solutions!!
– Develop and implement new controls in simulation tools – Simulation based validation of ancillary services from wind – Develop tools to assess the value of new ancillary services
• Developers / owners – Assess the value of new ancillary services
• System operators – Validate and implement strategies to ensure system security
• Turbine / plant manufacturers – Develop and implement new ancillary service capabilities in full
WPP scale 37 Danish Smart Grid Research Network 2014-09-05