Hitachi Energy was selected by Power Grid Corporation of India Ltd. to deliver the world’s first multi-terminal UHVDC transmission link. The ±800 kV North-East Agra UHVDC link with 8,000 MW converter capacity, including a 2,000 MW redundancy, transmits clean hydroelectric power from India's northeast region to the city of Agra, a distance of 1,728 km, equal to the distance from Florida to New York City.
The link comprises four terminals in three converter stations with a 33 percent continuous overload rating, enabling an 8,000 MW conversion - one of the most powerful HVDC transmission systems ever built.
Hitachi Energy and Bharat Heavy Electricals Ltd. (BHEL) had turnkey responsibility for execution, including system engineering, design, supply, and installation of three HVDC converter stations. Commissioning being completed in 2017.
Northeast India has abundant untapped hydropower resources scattered over a large area, but load centers are hundreds or even thousands of kilometers away. Power must pass through the so called, "chicken neck area," a very narrow patch of land (22 km width x 18 km of length) in the state of West Bengal having borders with Nepal on one side and Bangladesh on the other side.
One converter station is located in the northeastern state of Assam, and a second in the state of West Bengal in eastern India. The other end of the DC line terminates at Agra, where two bipolar converters are connected in parallel. The 800 kV equipment yard at Agra has, for the first time, been placed indoors.
This is the second Hitachi Energy built multi-terminal HVDC Classic link. In 1990-1992, a large-scale three terminal transmission link was constructed in North America called the Québec - New England HVDC Transmission - the first of its kind in the world.
At full capacity, the North-East Agra UHVDC link is able to supply enough electricity to serve 90 million people based on average national consumption. The ultrahigh voltage minimizes transmission losses, improves grid efficiency ensuring reliable, affordable, sustainable power to people and industries.
|Power rating:||6,000 MW (multi-terminal)|
|No. of poles:||Converter: 4
|AC voltage:||400 kV (all stations)|
|DC voltage:||±800 kV|
|Length of overhead DC line:||1,728 km|
|Main reason for choosing HVDC:||Long distance, bulk power|
|Application:||Connecting remote generation|