The document discusses high-voltage direct current (HVDC) transmission. It provides examples of HVDC projects around the world, including connections between countries in Europe and South America. It also discusses technical aspects of HVDC transmission such as converter stations needed to connect to AC grids. While HVDC transmission has higher upfront costs than AC transmission, it has lower transmission losses over long distances and provides more flexibility in transmission capacity.

1. Manuel S. Preckler Alonso

2.  Introduction
 HVDC transmission
 Technical aspects of HVDC
 Economic considerations
 Environmental issues
Index

3.  Introduction
 HVDC transmission
 Examples around the World
 UK – Continental Europe
 Brazil – Argentina
 Inter – Island in New Zealand
 Southern Hami – Zhengzhou UHVDC
 Changji – Guquan UHVDC
Index

4.  Introduction
 HVDC transmission
 Examples around the World
Index
 Examples in the US
 California
 New York –New Jersey
 References
 Questions?

5. Introduction
 Main Characteristics
 Definition: High-Voltage Direct Current (HVDC)
 HVDC usually uses voltages between 100 kV and 1,500 kV
 Mostly used in electricity transmission
[1]

6. AC transmission
 Most transmission lines are High-Voltage three-phase Alternating Current
(AC) rather than HVDC.
 Advantages:
 Voltage conversion is simple through an
AC transformer.
 AC transformer allows high power levels
and high insulation levels within one
unit.
 Transformer has low losses. It is a
relatively simple device, which requires
little maintenance.
 Three-phase Synchronous generator is
superior to a DC generator.
 Disadvantages:
 New connection between an AC system and a
meshed grid may be impossible because of
system instability, due to high short-circuit
levels or undesirable power flow scenarios.
 Direct connection between two AC systems
with different frequencies is not possible.
 Inductive and capacitive elements limit to
the transmission capacity and distance of AC
links (capacitance of underground cables is
much more than that of Overhead).

7.  What makes HVDC grids possible now?
 HVDC Light systems and components are, now, mature (Power Electronics
technology has improved enough to fulfill HVDC requirements).
 An efficient HVDC breaker is available. It can sectionalize multiterminal HVDC
systems into several protection zones to facilitate fault clearance with continuous
transmission in the non-affected areas.
HVDC transmission

8.  1. Technical aspects of HVDC
 A digital control system provides accurate and fast control of the active power
flow.
 Fast modulation of DC transmission power can be used to damp power
oscillations in an AC grid and thus improve the system stability.
HVDC transmission
AC DC AC

9.  1. Technical aspects of HVDC
 A DC link allows power transmission between AC networks with different
frequencies or networks, which can not be synchronized, for other reasons.
HVDC transmission

10.  1. Technical aspects of HVDC
 By using DC, the conductor cross section is fully utilized because there is no skin
effect.
HVDC transmission
DC AC

11.  1. Technical aspects of HVDC
 Inductive and capacitive parameters do not limit the transmission capacity or the
maximum length of a DC overhead line or cable.
HVDC transmission
[2]

12.  1. Technical aspects of HVDC
 Inductive and capacitive parameters do not limit the transmission capacity or the
maximum length of a DC overhead line or cable.
HVDC transmission
DC
AC
[2]

13.  Converter stations needed to connect to AC power grids are very expensive.
 The conversion process consumes reactive power. As a result, it is necessary to
install filter-compensation units and reactive power compensation units.
 Only two conductors are necessary to transmit electricity, and with lower losses
than AC systems of similar scope.
 2. Economic considerations
HVDC transmission

14. HVDC transmission
 2. Economic considerations
 DC Terminals >> AC Terminals
 DC Lines < AC Lines
 DC Losses < AC Losses
[3]

15.  Less visual impact (even less if it is underground).
 Transmission possibilities contribute to a more efficient utilization of existing
power plants and facilitate the inclusion of renewable energies.
 The land coverage and the associated right-of-way cost for an HVDC overhead
transmission line is not as high as that of an AC line.
 Less visual impact (even less if it is underground).
 3. Environmental issues
HVDC transmission
[4]

16.  Less visual impact (even less if it is underground).
 3. Environmental issues
HVDC transmission
[4]
AC Overhead Example

17.  Less visual impact (even less if it is underground).
 3. Environmental issues
HVDC transmission
[4]
DC Overhead Example

18.  Less visual impact (even less if it is underground).
 3. Environmental issues
HVDC transmission
[4]DC Underground Example

19.  Frequency is 50 Hz and Voltage 230 V
 Different Regional Groups
 Synchronous grid of Continental Europe
 RG Nordic
 RG UK
 RG Ireland
 RG Baltic
Examples around the World
 Europe
[5]

20.  UK – Continental Europe interconnections
 HVDC Cross-Channel (UK - France)
 2000 MW bi-pole system and ± 270 kV
 73 km (45 mi) long with 46 km (29 mi)
submarine cables
 BritNed (UK - Netherlads)
 1000 MW bi-pole system and ± 450 kV
 260 km (160 mi) long with 250 km (155 mi)
submarine cables
Examples around the World
 Europe
[5]

21. Examples around the World
 Europe
[6]

22. Examples around the World
 South America
 Brazil – 60 Hz
 Argentina – 50 Hz
[7]

23. Examples around the World
 South America
[7]
 Brazil-Argentina HVDC Interconnection
 2,200 MW (2 x 1,100 MW) with ± 70 kV (DC)
 500 kV (AC) (both sides)
 135 km (84 mi) in Argentina
 Crosses the Uruguay river (Border Arg-Brz)
 132 + 223 km (82 + 138 mi) in Brazil

24. Examples around the World
 South America
 Brazil-Argentina HVDC Interconnection
[7]

25. Examples around the World
 South America
 Brazil-Argentina HVDC Interconnection
[7]

26. Examples around the World
 South America
 Brazil-Argentina HVDC Interconnection

27. Examples around the World
 Oceania
 HVDC Inter-Island in New Zealand
 Connects hydro turbines in South Island and
North Island (where there is more electricity
consumption)
 1200 MW bipolar with ±350 kV
 534 km (332 mi) overhead lines in South Island
 40 km (25 mi) submarine cables
 37 km (23 mi) overhead lines in North Island
[8]
[9]

28. Examples around the World

29. Examples around the World
 Oceania

30. Examples around the World
 Asia
 Southern Hami–Zhengzhou UHVDC in China
 Transmission capacity of 8,000 MW
 Voltage is ± 800 kV
 Total length is 2,210 km (1,370 mi)
[10]

31. Examples around the World
 Asia
 Southern Hami–Zhengzhou UHVDC in China
 Transmission capacity of 8,000 MW
 Voltage is ± 800 kV
 Total length is 2,210 km (1,370 mi)
[10]

32. Examples around the World
 Asia
 Southern Hami–Zhengzhou UHVDC in China
 Transmission capacity of 8,000 MW
 Voltage is ± 800 kV
 Total length is 2,210 km (1,370 mi)
[11]
[10]

33. Examples around the World
 Asia
 The Changji-Guquan UHVDC in China
 Transmission capacity of 12,000 MW
 Voltage is ± 1,100 kV
 Total length is 3,293 km (2,046 mi)
 On Dec. 31, 2018
[10]

34. Video
https://www.youtube.com/watch?v=S0jVb1oOmh8

35. Examples in the US
 California
[12]

36. Examples in the US
 California
 Trans Bay Cable (San Francisco and Pittsburg)
 400 MW power with voltage ±200 kV
 Modular Multi-Level Converter (MMC) VSC
system
 53 mi (85 km)
[12]

37. Examples in the US
 California
[12]

38. Examples in the US
 California
[12]

39. Examples in the US
 California
[12]

40. Examples in the US
 New York – New Jersey
[13]

41. Examples in the US
 New York – New Jersey
 Neptune Project
 660 MW power with voltage ±500 kV
 It carries 22 percent of Long Island's electricity
 50 mi (80 km) undersea and 15 mi (25 km)
underground
[13]

42. Images
 [1] Federal Energy Regulatory Commission
 https://www.ferc.gov/industries/electric/indus-act/reliability/blackout/ch1-3.pdf
 [2] CIGRE Working Group B1.40. Offshore generation cable Connection
 http://www.e-cigre.org/publication/610-offshore-generation-cable-connections
 [3] SIEMENS High Voltage Direct Current Transmission.
 www.siemens.com/energy/hvdc
 [4] ABB Introducing HVDC
 https://new.abb.com/systems/hvdc/
 [5] Synchronous grid of Continental Europe
 https://en.wikipedia.org/wiki/Synchronous_grid_of_Continental_Europe
 [6] First published in The Economist, U.K., February 2nd, 2019, By Kal

43. Images
 [7]“Garabi” the Argentina – Brazil 1000 MW Interconnection Commissioning
and Early Operating Experience
 https://new.abb.com/systems/hvdc/references/brazil-argentina-hvdc-interconnection
 [8] New Zealand HVDC Inter-Island
 https://new.abb.com/systems/hvdc/references/new-zealand
 [9] Siemens completes HVDC transmission link for New Zealand
 https://www.siemens.com/press/en/feature/2013/energy/2013-09-hvdc.php#ii141
 [10] UHV State Grid Corporation of China
 http://www.sgcc.com.cn/html/sgcc_main_en/col2017112610/column_2017112610_1.shtml
 [11] Zhongzhou Converter Station (800kV UHV DC Transmission Project)
 https://www.zhihu.com/question/20737584

44. Images
 [12] TRANS BAY CABLE
 http://www.transbaycable.com/
 [13] Neptune Regional Transmission System
 http://neptunerts.com/

45. Questions?

46. THANK YOU.

48. Questions
 Mature Technology
 Performance
 Costs

49. Questions
 Mature Technology
 Performance
 Costs