Siemens AG Power Transmission Solutions J. Dorn, … · Siemens AG Power Transmission Solutions J....
Transcript of Siemens AG Power Transmission Solutions J. Dorn, … · Siemens AG Power Transmission Solutions J....
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
CIGRE Colloquium on HVDC and Power Electronic Systems Wednesday March 7 through Friday March 9, 2012
Hotel Nikko, San Francisco, California, USA
Trans Bay Cable –
A Breakthrough of VSC Multilevel Converters in HVDC Transmission
Siemens AG
Power Transmission Solutions
J. Dorn, [email protected]
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Content
Overview
Operational Experience
Further Development Aspects
Impressions of Trans Bay Cable
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
►
Overview
Operational Experience
Further Development Aspects
Impressions of Trans Bay Cable
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable -
The Initial Situation
Situation before Trans Bay Cable: Bottlenecks in the Californian
grid
Problem: No right of way for new lines or land cables
The solution:
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable –
Key Data
Pittsburg Substation
Potrero Substation
< 1 mile 53 miles1 mile 1 mile < 3 miles
San Francisco Pittsburg
Cables
AC/DCConverter
Station
Cables
AC/DCConverter
Station
ACAC
115 kV Substation
230 kV Substation
•
Converter: Modular Multilevel HVDC PLUS Converter•
Rated Power: 400 MW @ AC Terminal Receiving End•
DC Voltage: ±
200 kV•
Submarine Cable: Extruded Insulation DC Cable•
Start of Commercial Operation November 2010
• Converter: Modular Multilevel HVDC PLUS Converter• Rated Power: 400 MW @ AC Terminal Receiving End• DC Voltage: ±
200 kV• Submarine Cable: Extruded Insulation DC Cable• Start of Commercial Operation November 2010
Submarine DC Cables
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
HVDC PLUS
Modular Multilevel Converter –
Basic Scheme
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
Ud
Phase Unit
SM
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Overview
►
Operational Experience
Further Development Aspects
Impressions of Trans Bay Cable
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Operational Experience:
AC Under-Voltage Fault
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Operational Experience:
Step Response in terms of Converter Arm Energies
Step Response of vertical balancing control in terms of converter arm energies.
No influence on AC currents!
-1,5
-1
-0,5
0
0,5
1
1,5
0,05 0,07 0,09 0,11 0,13 0,15 0,17 0,19 0,21 0,23 0,25
Zeit t [s]
Ein
gang
s- u
nd A
usga
ngss
trom
i [p
u]
0,6
0,65
0,7
0,75
0,8
0,85
0,9
0,95
1
0,05 0,07 0,09 0,11 0,13 0,15 0,17 0,19 0,21 0,23 0,25
Zwei
gene
rgie
w [p
u]
AC
Cur
rent
s (n
orm
aliz
ed)
Con
vert
er A
rm E
nerg
ies
(nor
mal
ized
)
Time (sec)
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
-1,5
-1
-0,5
0
0,5
1
1,5
0,25 0,27 0,29 0,31 0,33 0,35 0,37 0,39 0,41 0,43 0,45
Zeit t [s]
Ein
gang
s- u
nd A
usga
ngss
tröm
e i [
pu]
AC
Cur
rent
s(n
orm
aliz
ed)
0,6
0,65
0,7
0,75
0,8
0,85
0,9
0,95
1
0,25 0,27 0,29 0,31 0,33 0,35 0,37 0,39 0,41 0,43 0,45
Zwei
gene
rgie
n w
[pu]
Con
vert
er A
rm E
nerg
ies
(nor
mal
ized
)
Time (sec)
Step Response of horizontal balancing control in terms of converter arm energies.
No influence on AC currents!
Operational Experience:
Step Response in terms of Converter Arm Energies
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Equivalent disturbing current in the range from 60 Hz to 5.1 kHz.
Operational Experience:
Harmonics: Converter phase to ground voltages
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Operational Experience:
Harmonics: DC current
Total harmonic distortion of converter phase to ground voltages in the range from 120 Hz to 3 kHz clearly below 1%.
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Operational Experience:
Losses
Total losses between the two AC systems within the specified limits.
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Overview
Operational Experience
►
Further Development Aspects
Impressions of Trans Bay Cable
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Further Development Aspects:
Increase of Current Capability
Half Bridge Submodule with parallel connection of IGBTs to increase the current capabability
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Further Development Aspects:
Full Bridge Submodules
•
AC voltage instead of DC voltage possible
•
DC pole-to-pole fault can be turned off by IGBTS
•
Higher losses compared to half bridge submodules
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
SM 1
SM 2
SM n
u
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Further Development Aspects:
Clamp-Double Submodule
•
Double voltage capability compared to half bridge submodule and full bridge submodule
•
Capability to turn off a DC pole-to-pole fault with IGBTs
but
•
Lower losses than full bridge Submodule
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Further Design Aspects:
Requirements for Offshore Wind Grid Access
Main goal: Keep windfarm operational at all costs / prevent wind
turbine shutdown
Wind turbines have only 100 ... 200ms Fault Ride Through (FRT) capability
Onshore Grid Codes, however, require interruption capability of > 1s
Windfarm output power has to be kept up during this period
There are no feasible means of storage for the excess power, so where to put it?
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Further Design Aspects:
Braking Chopper Submodule for Grid Access
Possible solution: DC braking chopper
absorbs dynamic excess power generated by the windfarm during onshore grid interruptions
For enduring grid faults, the windfarm may be throttled down in usual order, via windfarm power control –
no emergency shut-down
The chopper is installed at the onshore converter station,the offshore station‘s footprint is not enlarged.
Windfarm will take no notice of short onshore grid interruptions
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Further Design Aspects:
Series Connection of Power Semiconductors
Usually, a semiconductor device failure does not lead to a discharge of the capacitor.
But:
•
A faulty semiconductor has to have the capability for load current
•
Or: Bypass device
•
Short circuit of a whole half bridge shall be considered (impact on neighbored submodules)
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Overview
Operational Experience
Further Development Aspects
►
Impressions of Trans Bay Cable
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable Some Impressions
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable Some Impressions
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable DC Yard
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable AC Yard
Cigre Colloquium on HVDC and Power Electronics SystemsMarch 7 through 9, 2012
Trans Bay Cable Converter Hall