Itaipu, Brazil – the world’s biggest HVDC transmission of power
The contract for the largest of all HVDC transmission schemes to date, the 6300-MW Itaipu HVDC link in Brazil with a world record voltage of ±600 kV DC, was awarded to the ABB-PROMON consortium in 1979. This project was completed and put into operation in several stages between 1984 and 1987. It plays a key role in Brazil’s power planning, supplying a large amount of the electricity needed in the city of São Paulo.
The scale and technical complexity of the Itaipu project presented a considerable challenge, and it can be considered as the start of the modern HVDC era. The experience gained in the course of its completion has been in no small way responsible for the many HVDC orders awarded to ABB since then.
Cross Sound Cable – the world’s largest HVDC Light project
Cross Sound Cable is an HVDC Light underwater cable link between Connecticut and Long Island, New York. The owner is TransEnergie U.S., a subsidiary of Hydro-Québec. The Cross-Sound link improves the reliability of power supply in the Connecticut and New England power grids, while providing urgently needed electricity to Long Island.
When the blackouts hit the eastern United States last August, the Cross Sound cable link was activated and restored power quickly and efficiently to tens of thousands of consumers. HVDC Light’s “black start” capability means it can power up networks that have suffered a 100 percent failure.
Murraylink, Australia – the world’s longest underground high-voltage connection
The Murraylink 220 MW interconnector between the Riverland in South Australia and Sunraysia in Victoria is a 177 kilometer underground high-voltage power link. Murraylink is the world’s longest underground transmission system.
Murraylink also benefits both South Australia and Victoria by enabling electricity trading in Australia’s deregulating power market.
The project won the 2002 Case EARTH Award for Environmental Excellence for best practice and innovation in the environmental management of civil construction projects. In 2003, it also won an engineering award. Underground cable was chosen instead of overhead transmission lines to reduce visual and environmental impact, and to protect against Australia’s traditional causes of power outages such as lightning, wild life or bush fires.
China – setting new standards
In China, ABB has installed two long distance HVDC links from the Three Gorges power plant to the major load centers in Shanghai and Guangdong. This involves two turnkey 3000 MW HVDC transmission systems, including the most powerful converters in the world, 1500 MW per pole.
ABB is also setting new standards for speed. The HVDC link from Three Gorges to Guangdong has been built in record time – 32 months – one year faster than the industry norm. At 975 km, this link is the longest DC-line in its class (Itaipu is 805 km).
Both links carry enough power to supply about six million Chinese households. Due to their small transmission corridors, they save about 16,700 hectares of farmland and forest. They also save about 78 MW through avoidance of losses – enough to supply for 156,000 households.