Grid Code Testing of Wind Turbines by VSC-based Test...
Transcript of Grid Code Testing of Wind Turbines by VSC-based Test...
![Page 1: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/1.jpg)
1 of 32
VÄRLDENS SKILLNAD
Grid Code Testing of Wind Turbines by
VSC-based Test Equipment
Nicolás Espinoza, PhD Student
CHALMERS UNIVERSITY OF TECHNOLOGY
Gothenburg, Sweden.
![Page 2: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/2.jpg)
2 of 15
Project Description • Aim of the project
– To develop methods for grid code testing of wind turbines using
VSC-based test system.
• Activities
– Grid code analysis for interconnection of wind parks.
– Control theory of WT and VSC.
– Mathematical model for stability analysis.
• Results
– Simulation of the WT and the VSC-based test equipment (TE).
– Laboratory experiment at Power System Lab in Chalmers.
– Field test of full power 4 MW WT with 8 MW HVDC system in
Göteborg harbor has started!
![Page 3: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/3.jpg)
3 of 15
Wind Power Increase • World total installed capacity is 318 GW (117 GW are inside EU)
• 40 GW per year in the last 5 years, approximately.
Year
GW installed
![Page 4: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/4.jpg)
4 of 15
Grid code development • Regulates the interconnection of the generating plant.
• Special requirements for wind parks.
• Steady state: voltage, power and frequency ranges.
• Dynamic: LVRT and reactive current injection (if allowed).
• Grid code harmonization: ENSTO, Nordic.
![Page 5: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/5.jpg)
5 of 15
Low Voltage Ride Through (LVRT) • Voltage dip representation at the connection point
0
0 1
0.3
0.4
0.5
0.6
0.2
0.1
0.7
Sy
stem
Vo
ltag
e [p
u]
Time [s]
E.ON (Germany)
Energnet.dk (Denmark)
Red Eléctrica España (Spain)
0.8
0.9
1
2 30.50.25 0.75 1.25 1.5 1.75 2.25 2.5 2.75
Svenska Kraftnät (Sweden)
Nordel
EirGrid (Ireland)
National Grid (U.K.)
![Page 6: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/6.jpg)
6 of 15
Wind Turbine Topologies
G
Output
transfomer
Full Power Converter
Coupling
inductor and
filtersAC
DC AC
DC
AC Grid
Gearbox/
Gearless
Control system
Wind turbine
Protection by DC crowbar
Generator
Full-size converter WT
• Grid synchronization
• Current during fault is fully
controlled.
• LVRT control.
DFIG WT
• Stator connected to the grid.
• High transient current during fault.
• VSC rated in 1/3 P nominal.
• Poor LVRT capability.
Output
transfomer
1/3 Power Converter Coupling
inductor and
filtersAC
DC AC
DC
AC Grid
Gearbox
Control system
Wind turbine
Protection by DC crowbar
DFIG
Protection by AC crowbar
![Page 7: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/7.jpg)
7 of 15
Wind Turbine Modelling
Assumptions
• Physical decoupling between
Generator and grid.
• Mechanical transients are slow
compare to electromagnetic
transients.
wfR ,
wu wti , we
wfL , wfC ,
DC
AC
wDCu ,wDCi ,
wDCC ,
WT-VSC
si
GENP
crbR
To Test
equipment
crbsw
TWgwe , gwi ,
G
Output
transfomer
Full Power Converter
Coupling
inductor and
filtersAC
DC AC
DC
AC Grid
Gearbox/
Gearless
Control system
Wind turbine
Protection by DC crowbar
Generator
![Page 8: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/8.jpg)
8 of 15
Grid Code Testing Equipment
Test Equipment: VSC in back-to-back
AC voltage
control for
LVRTInterface
impedance
AC
GridInterface
impedance
AC
DC AC
DCPCC
Coupling
transfomer
Coupling
trasnformer
DC voltage
control
• Impedance-based
• VSC-based
Z series
Z faultAC
Impedance-based
Test equipment
Grid impendace
![Page 9: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/9.jpg)
9 of 15
Stability Analysis • Analytical model based on physical equations and control equations.
• Study of interactions between WT and Test Equipment
wfR
,
wu
wti
, we
wfL
, wfC
,
DC
AC
wDCu
,wDCi
,
wDCC
,
WT-VSC
si
AC
DC
PCC
eg
i ut
i
fC
fR
fL
Interface impedance Collector-VSC
eqR
eqL
CL vs OL voltage CTRL
Blue: P-based controller
Red: PI-based controller
Black: Open-loop Well damped area
![Page 10: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/10.jpg)
10 of 15
Laboratory Setup
utie
1,1, , ff RL
DCu
DCC
Grid Emulator DC machine360 V
DS1103
2,2, , ff RLfC
AC voltage control for LVRT
AC
DC AC
DCwtu , wti ,
AC grid, 400 V, 50
Hz
lR
wDCC ,
wDCu ,
crbR
DS1103
Wind Turbine Model AC-link
wtwt QP ,
• Placed at the Power System Lab. at Chalmers University of Technology.
• Consisting of 2 DC-sourced VSC interfaced by an AC-link.
• 200 V, 10 kVA.
![Page 11: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/11.jpg)
11 of 15
![Page 12: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/12.jpg)
12 of 15
![Page 13: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/13.jpg)
13 of 15
Field Test Results
![Page 14: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/14.jpg)
14 of 15
Turbine
VSC
AC
DCAC
Utility Grid
Flexible VSC-based Testing Equipment
Grid VSC
DC
AC
![Page 15: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/15.jpg)
15 of 15
Conclusions and Future Work
Conclusions
• Need for regulations for renewable energy sources.
• VSC-based T.E. is flexible
• Development of PCC voltage control and control algorithms.
Future Work
• To develop control strategies for testing of:
– Voltage control
– Power oscillation damping
– Frequency control
• Characterization of wind turbines
• To include wind turbine mechanical system
![Page 16: Grid Code Testing of Wind Turbines by VSC-based Test Equipmentstandupforwind.se/digitalAssets/491/491178_3nicol... · VSC-based test system. • Activities – Grid code analysis](https://reader030.fdocuments.net/reader030/viewer/2022041013/5ec20267f4a2bb165300bd1a/html5/thumbnails/16.jpg)
16 of 15
Thanks for your attention
Nicolás Espinoza, PhD Student
CHALMERS UNIVERSITY OF TECHNOLOGY
Gothenburg, Sweden.