A new 2,000km power superhighway is to be built in China using advanced ABB technology. The ultra high-voltage direct current (UHVDC) link will transmit electricity at ultra-high voltage (kV).
The 6,400MW link will take power from the Xiangjiaba hydropower plant in western China to the industrialised coastal area around Shanghai in the east. It will meet the needs of about 31 million people and is due to be completed in 2011.
ABB has been awarded orders worth US$440 million by the State Grid Corporation of China and other partners.
The power rating is more than twice that of the most powerful rating in operation today and the transmission line will be the longest in the world.
The UHVDC link – consisting of two substations and a power transmission system – will transmit electricity at ultra-high voltage (800kv), minimising transmission power loss.
Increasing the voltage level of electrical transmission produces considerable environmental advantages, including lower electricity losses and the need for less land space compared with traditional overhead lines. UHVDC is particularly suitable for vast countries like China, where the centres that need power are often located far from the power sources.
This project represents a number of breakthroughs in electrical power transmission:
• the 6,400MW power rating is more than twice that of the most powerful currently in use, and
• at 2,000km, the transmission line will be the longest in the world
Transmission losses will be less than seven per cent – significantly less than the losses from conventional 500kV HVDC transmission schemes. The savings produced by UHVDC compared with HVDC are equivalent to the annual power consumption of more than 900,000 people in China.
“Ultra-high voltage transmission is a vital new technology for the efficient use of hydropower generated in remote areas,” said Peter Leupp, head of ABB’s Power Systems division. “ABB technology, which plays an essential role in this project, can support the economic development of some of the world’s most populous regions, while reducing environmental impact."
UHVDC savings over HVDC are equal to 900,000 people’s annual power consumption
UHVDC transmission is a further development of HVDC, a technology pioneered by ABB more than 50 years ago. The new technology, uses thyristor valves equipped with newly developed six-inch thyristors (power semiconductors) and an advanced control system, providing the biggest capacity and efficiency leap in 20 years. The increase became possible following advances in basic research in a number of fields, including the development of new materials for outdoor insulators and advanced control systems with extremely high processing capacity.