Xiangjiaba - Shanghai

State Grid Corporation of China (SGCC) is the owner of the link and Hitachi Energy the main technology supplier. The project was completed in 30 months, one year ahead of schedule.

The ±800 kV Xiangjiaba-Shanghai Ultrahigh Voltage Direct Current (UHVDC) link, with a rated power of 6,400 MW, has the capacity to transmit up to 7,200 MW of power from the Xiangjiaba hydropower plant, located in the southwest of the country, to Shanghai, China's leading industrial and commercial center, about 2,000 kilometers away.

For this turnkey project, Hitachi Energy was responsible for overall system design and supply of the main equipment, including 28 high and ultra high-voltage converter transformers, ten from Sweden and the rest manufactured with Hitachi Energy components and technology in China, in local partnership. Other key products delivered include thyristor valves, DC and AC switchyard equipment and the DCC800 HVDC control system.

The Xiangjiaba-Shanghai UHVDC transmission link represents a major breakthrough in the technology of electric power transmission.  System voltage at ±800 kV is 33 percent higher than the voltage used for the ±600 kV Itaipu transmission in Brazil, which until now was the world’s highest HVDC transmission voltage rating. The power rating at 6,400 MW is also record breaking, while losses were reduced to 7 percent, compared to 10 percent losses on conventional 500 kV DC transmission lines.

Overhead line length at 1,980 km makes Xiangjiaba-Shanghai one of the longest overhead transmission links in the world, surpassed only by the Rio Madeira HVDC link currently under construction in Brazil, which is about 2,400-km long.