Ultra High Voltage DC Systems

800 kV Ultra High Voltage Direct Current (UHVDC) transmissions are economically attractive for bulk power transmissions of 5,000 – 8,000 MW over 1,000 – 1,500 km or above. 800 kV HVDC transmission projects are already in execution phase, and 800 kV is now an established voltage level for bulk power transmission over long distances.

ABB started with the development for 800 kV equipment to make this voltage increase possible. ABB also planned for a long time test circuit installation to establish a confidence in this new voltage level. The long term test circuit installation has been energized at 855 kV since November 2006 at the STRI Laboratory in Sweden. It has well served its purpose in providing final qualification for the newly developed products and boosting confidence in 800 kV HVDC technology with several utilities around the world.

ABB was awarded the converter equipment for the Xianjiaba - Shanghai ±800 kV HVDC Transmission project rated for 6,400 MW to transmit power over a distance of over 2,000 km by State Grid Corporation of China in December 2007.