Control challenges for grid integration...Control challenges for grid integration Objectives...
Transcript of Control challenges for grid integration...Control challenges for grid integration Objectives...
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for gridintegration
Nicolaos A. Cutululis, DTU Wind Energy17 January 2019, DeepWind Conference, Trondheim
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
• Background• Diode Rectifier as offshore HVDC• Grid Forming Wind Turbines• Offshore AC Grid Start-up• Black Start by Offshore Wind Turbines
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Acknowledgements:Ramón Blasco Jiménez & team, UPVLie Xu & team, UoSÖmer Göksu & Oscar Saborío-Romano, DTU
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Offshore wind development
3Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Offshore wind development
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Source: IRENA, Offshore innovation widens renewable energy options, September 2018
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Offshore wind development
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Main cost components of offshore wind farms:- turbines (including towers) - the foundations - the grid connection to shore
- AC or DC?
Power flow is in one direction onlyWhy not use a diode rectifier offshore?
Source figure: ABB, onlineSource: IRENA, Offshore innovation widens renewable energy options, September 2018
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
PROMOTioN projectProgress on Meshed HVDC Offshore Transmission Networks
6Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Objectives
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Objective 1Define functional
requirements to OWFs
Objective 2Develop test cases & control algorithms
Objective 3Define & apply
compliance evaluation
Objective 4 Recommend grid
code requirements
HVDC linkVSC
onshore
DRUDiode Rectifier Unit
Grid Forming WPP
DC -
DC +
dqabc
-+
ω
dqabc
refPFdU
FqCUω
sdI
0U
dqabc
Cable
Active power control
Voltage controlFrequency
controlReactive power sharing controlCurrent control
PLL
++
+1s
+-
++
-
+-
+-
+
-+
0Q
FqU
FdCUω
sqI+
-
+-
+
+
+-
++
fk qk
0ω
ω
FqU+
θ
+
FdU
FqU
cdU
cqU+
UFUC Is dcI
dcrU
+
WT line-side converter
R L C
0ω
refω
wtP
wtQ
wtP wtQ
WdI
WqI
WdLIω
FdrefU
FqrefU
WdrefI
WqrefI
WqLIω
IW
UFIW
lilp
kk
s+
Uoff
pipp
kk
s+vi
vp
kks
+
vivp
kks
+
iiip
kks
+
iiip
kks
+
Time[s]
Voltage [%]
0%
100%
85%
3
130%
90%
110%
120%
1802 50.25
~~~~
~~
115%
60
...permanent operating area...
?
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Diode Rectifier Units as offshore HVDC
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currentVSC
solution
WPP transformers
HVDC offshore terminal
VSC-MMC
HVDC link
VSC-MMConshore
HVDC link
VSC-MMConshore
Diode-Rectifier Units (DRUs)
new DRU solution
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Grid Forming Wind Turbines
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GearBox
Generator
WT transformer
WPP transformer
WT transformer
ACDC AC
DC
HVDC transformer
VSC - HVDC Offshore HVDC
Onshore
Onshore AC Grid
WT Control
Offshore Voltage & Frequency
ACDC
ACDC
GearBox
Generator
ACDC
ACDC
WT Control
Active & Reactive Power
Active & Reactive Power
Grid following wind turbines
GearBox
Generator
WT transformer
WT transformer
ACDC AC
DC
Diode Rectifier Unit HVDC Onshore
Onshore AC Grid
WT Control
ACDC
ACDC
GearBox
Generator
ACDC
ACDC
WT Control
Active & Reactive PowerVoltage & Frequency Control
Grid forming wind turbines
Active & Reactive PowerVoltage & Frequency Control
Grid forming wind turbines control- dq current control based
- voltage/angle control based- VSM control
- GPS synchronization based- master/slave based
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Offshore AC Grid Start-up Options
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VSC-MMC
VSC-MMConshore
HVDC link
VSC-MMConshore
DRUs
Onshore AC Grid
Umbilical AC Cable Nearby VSC-HVDC (or AC)
HVDC link
VSC-MMConshore
DRUs
Energy Storage
Local Energy Storage (e.g. battery, diesel)
HVDC link
VSC-MMConshore
DRUs
es
es
es
Black-startable wind turbines
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Some results – AC grid start-up (string connection)
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www.promotion-offshore.net, Deliverable 3.4: Results on control strategies of WPPs connected to DR-HVDCTrondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
www.promotion-offshore.net, Deliverable 3.5: Performance of ancillary services pro-vision from WFs connected to DR-HVDC
Control challenges for grid integration
Some results – Frequency control
12Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Black-start - Progress Towards Demonstration
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Outside PROMOTioNEnerginet performs Black Start field test with Skagerrak 4 (SK4) HVDC interconnector
WP3 Performs Black Start Simulation Test with Offshore WPPTo energize:• 3 buses • Overheadline & underground cable• Shunt reactor & transformer• Step MW++ load
• Load changes• Frequency & voltage setpoint changes• Load disconnection
Results to be compared against HVDC field tests by Energinet
SK4
[https://ens.dk/sites/ens.dk/files/Statistik/el_produktion_og_transmission_2017_300dpi.pdf]
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Scenarios – Self-Energization & Black Start
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WPP1 400MW
BKT1
Off-shore Comp. Reactor
BKst1
BKst2
BKst3
BKst4
BKst6
66/220 kV
Off-shoreTransformer
BKT2
PcableQcable
75 km
On-shoreTransformer VSG
ZS
On-shoreNetwork
ISVS
ωS
Vo
220/400 kV
BKst5
BKT3
On-shore Comp. Reactor
BKT3
PT1QT1
VT1IT1
PT2QT2
VT2IT2
PT3QT3
VT3IT3
HVAC-connected OWPP
HVDC-connected OWPP(s) with AC collector substation(s)
HVDC-connected OWPP(s) directly (66kV) connected to the HVDC
Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Some results – black-start
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© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Some results – black-start
16Trondheim 17.01.2019
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Models for Control of WT/WPP Connected to DR- HVDCConfidential - only for members of the consortium
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Aggregated single WT Ideal onshore DC voltage Ideal WT DC voltage
Offshore AC start-up Voltage & frequency control Active power setpoint control Offshore AC fault ride-through Intentional islanded operation
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Achievements
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Control and Modelling Novel grid forming wind turbine controls Confidential grid forming WPP simulation models
Academic (white-box) & Industrial (black-box)
Operation of DRU HVDC Systems Functional requirements for Diode-Rectifier (DRU) connection of Wind Power Plants Control algorithms and simulation test cases & results Proof of DRU concept via simulations
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Control challenges for grid integration
Main Findings and Challenges
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Operation of DRUs• Wind turbines can operate with DRU-connection without any
degradation compared to VSC• Wind turbines can operate as islanded (idling, self-sustaining)
Fault Handling in DRU-connected OWPP • DRU inherent response to DC link voltage
eases onshore AC fault ride-through
Ancillary Services by DRU-connected OWPP• DRU connected OWPP can contribute to
frequency support and oscillation damping
OWPP Self-energization and Black Start• OWPP can energize its AC network and might be able to
contribute to black start
Onshore AC Grid
© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Any Questions?
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