HVDC Project 1, Group 3 ECE 421web.eecs.utk.edu/~kaisun/Backup/ECE421_Fall2014/Group2_HVDC... ·...
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ECE 421 Project 1, Group 3 HVDC Brian Beilstein, Robert Germick, James Haney, Alexander Joss, Matt Murphy, Shutang You
Transcript of HVDC Project 1, Group 3 ECE 421web.eecs.utk.edu/~kaisun/Backup/ECE421_Fall2014/Group2_HVDC... ·...
ECE 421 Project 1, Group 3HVDCBrian Beilstein, Robert Germick, James Haney, Alexander Joss, Matt Murphy, Shutang You
History and Basic Theory● First HVDC link in Sweden● Mercury Arc Rectifiers● Silicon Thyristors● Capacitor Commutated Converter (CCC)
State-of-the-art Design and Products● DC Breaker
○ Low impedance of HVDC system■ Faster opening speed■ Wider air gap
● Thyristor valves○ Can be used to go from AC-DC or DC-AC○ Used in renewables
Hybrid DC Breaker● Used to overcome issues of breaking DC
o No zero-crossings with voltage as in AC● In the case of a fault
o Load-commutating switch directs current to the main breaker
o Arrestor across the main breaker absorbs currento Ultra fast disconnector opens to isolate the LCSo Main breaker opens a number of IGBT bank
depending on whether interruption or limitation is required
Hybrid DC Breaker Sequence of Events
http://www05.abb.com/global/scot/scot221.nsf/veritydisplay/22d1af449957bf28c1257d070046df97/$file/Technical%20Assessment%20of%20Load%20Commutation%20Switch_IPEC2014.pdf
Thyristor Valve● Typically will use electronically triggered or
light triggered thyristors for control.● Thyristors are typically found in large stacks
and are water cooled
http://www05.abb.com/global/scot/scot221.nsf/veritydisplay/3c981b9078f55447c1256feb0022602a/$file/ett%20vs%20ltt.pdf
Impacts - Benefits● Undersea cables● Useful in connecting remote areas/plants
o End to end long haul bulk transmission● Reduced cost in…
o Increasing capacitance of existing grido Line cost - less wiring, conductors, and lower pylon profile
● AC systems compatibleo Transmission between unsynchronized AC systemso Stabilization of AC grid
● Reduced corona losses
Impacts - Concerns● Higher overall cost
o Expensive inverter stations for connecting to AC grido Requires filter and reactive power compensation unitso Design and operational complexity
● Short circuits in connect AC systems causes HVDC faults● Substation construction limit
o Requires minimal capacity difference● Creates radio noise in communication lines● Current causes electro-corrosion of underground metal pipes● Difficult to ground preventing ‘step voltage’
Challenges- Cost of HVDC components and availability- Conversion from AC to DC
- Cost and losses in conversion may not be offset in by the lower transmission losses and line construction.
- Limited overload capacity - Complex control needed for Multi Terminal
Systems
R&D Development- Offshore HVDC
- Useful for offshore wind-farms- Need for projects with Higher DC voltage
and rating- Improvements in Converting to HVDC
- Voltage Source Converters (VSC)- Multi Terminal HVDC systems- HVDC breakers
Current ApplicationsNorth America
Existing - 12Projects Planned - 4Projects Under Construction - 3
EuropeExisting - 49Projects Planned - 0Projects Under Construction - 2
Current Applications cont.Asia
Existing - 52Projects Planned - 0Projects Under Construction - 0
Red - Existing
Green - Under Construction
Blue - Possible additions
Specific Existing ProjectsOctober 23, 2014 - Alstom announces €800 million in new contracts to build HVDC “Energy highways”.
South Korea - HVDC Line Commutated Converter project
India - ~800kV, 3000MW Ultra-high voltage DC connecting Champa to Kurukshetra
Related ResearchModular Multilevel Converter for HVDC System
HVDC-Station using Modular Multilevel Converter
SM
SM
SM
a) Half-Bridge Submodule (SM) b) Full-Bridge Submodule (SM)
Internal structure of typical submodules
OR
Ref: Marquardt, R. "Modular Multilevel Converter: An universal concept for HVDC-Networks and extended DC-Bus-applications." Power Electronics Conference (IPEC), 2010 International. IEEE, 2010.
Conventional VSC-HVDC convertersThree-level converterTwo-level converter
Ref: http://en.wikipedia.org/wiki/HVDC_converter
Modular Multilevel Converter for HVDC System
Ref: http://en.wikipedia.org/wiki/HVDC_converter
Modular Multilevel Converter for HVDC System
Comparison of the arm currents of Two-Level Converter and the M2C
Comparison of the AC-line voltages of Two-Level Converter and the M2C
Ref: Marquardt, R. "Modular Multilevel Converter: An universal concept for HVDC-Networks and extended DC-Bus-applications." Power Electronics Conference (IPEC), 2010 International. IEEE, 2010.
Two-Level Converter
Modular Multilevel Converter
Two-Level Converter
Modular Multilevel Converter
Ref: Marquardt, R. "Modular Multilevel Converter: An universal concept for HVDC-Networks and extended DC-Bus-applications." Power Electronics Conference (IPEC), 2010 International. IEEE, 2010.
Application of M2C in multi-terminal HVDC
A Multi-terminal HVDC Network with 3 branches
Station 1 Station 2
Station 3Failure current
line-to-line fault
Clamp-Doule submodule
Questions?
