HVDC > HVDC References > Asia > Xiangjiaba - Shanghai
The world's longest transmission link with breakthrough technology
800 kV UHVDC (Ultra High Voltage Direct Current) technology will be used for the longest power transmission in the world. The link, owned by the State Grid Corporation of China, will transmit 6,400 MW power from the Xiangjiaba hydro power plant, located in the southwest of China, to Shanghai, China's leading industrial and commercial center, located 2,071 km (1,286 miles) away.
The Xiangjiaba - Shanghai transmission link represents a major breakthrough in the technology of electric power transmission in many aspects:
- The new system voltage ±800 kV is 33% higher than the voltage used for the Itaipu ±600 kV transmission in Brazil, until now the world’s highest HVDC transmission voltage rating.
- The power rating, 6,400 MW, is more than double the power rating of the most powerful transmission in operation today.
- The overhead line length, 2,071 km, will be the longest overhead transmission in the world, compared with 1,700 km for the Inga-Shaba HVDC transmission in Kongo-Kinshasa, until now the world’s longest transmission line.
- The losses for this long line will be reduced to 7% compared with 10% if the line had been built with conventional 500 kV DC transmissions.
| ABB has invested in equipment development, manufacturing and testing facilities to enable this new technology to be used in commercial operation. The developed equipment has been under successful test operation at 850 kV DCsince November 2006. The test set-up has been organized at the STRI laboratory in Ludvika, Sweden. | 
STRI laboratory with 800 kV UHVDC test installation |
Representatives from State Grid Corporation of China visiting the 800 kV UHVDC test installation in Sweden.
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| Visiting test installation in August 2006, guests include Mr. Lin Zhen Ya, President of SGCC. Click for larger image. | Visiting test installation in February 2007, guests include Mr. Shu Yin Biao, Executive Vice President of SGCC. Click for larger image. |
To the Xiangjiaba - Shanghai link, ABB will supply system engineering including design, supply and installation of the two converter stations including 800 kV HVDC power transformers and switchgear, valves provided with newly developed 6 inch thyristors and advanced control equipment.
The system is scheduled to go in operation in 2011.
| Main data |  |
| Commissioning year: | Pole 1: 2010, Bipole: 2011 |
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| Power rating: | 6 400 MW |
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| No. of poles: | 2 |
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| AC voltage: | 525 kV (both ends) |
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| DC voltage: | ±800 kV |
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| Length of overhead DC line: | 2 071 km |
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| Main reason for choosing HVDC: | Long distance |
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