Three Gorges-Changzhou was the first of two HVDC power links connecting the Three Gorges hydropower project on the Yangtze River in central China to major load centers of Shanghai and the surrounding area on the eastern coast.
ABB built two converter stations for this 3,000 MW ±500 kV HVDC power transmission system, which is owned by China's State Grid Corporation. The 890-kilometer power link began commercial operations in 2003. It more than triples the amount of power delivered from central China to the coast, from 1,200 megawatts (MW) to 4,200 MW. In 2004 ABB was awarded the converter stations for a second 3,000 MW HVDC transmission line to Shanghai.
ABB's HVDC technology promotes more efficient use of energy resources by transmitting large power loads over long distances with low losses. The link helps to meet the growing demand for power in Shanghai, China's leading industrial and commercial center.
One HVDC converter station is located at Longquan, about 50 km from the Three Gorges power plant; the other, Zhengping, is in the city of Changzhou, which is about 80 km northwest of Shanghai.
Because the Three Gorges project and associated transmission projects are extremely important to both sending side and receiving side power systems, high availability and low forced outage rate are required. Advanced technologies are used in all important design aspects, flexibility of operation is built into the design, and maintenance requirements are minimized.