HVDC > HVDC References > North America > Quebec - New England
The first large scale mutiterminal HVDC transmission in the world.
When ABB was awarded the contract for the Québec- New England Phase II HVDC project in 1986 by Hydro Québec and National Grid USA (formerly New England Electric Systems), it was the first large multi-terminal HVDC system ever contracted. The power is generated at the La Grande II hydro power station in the James Bay area, converted into DC at the Radisson Converter Station, and transmitted over the multi-terminal system to load centers in Montreal and Boston.
Phase I of the bipolar HVDC transmission consisted of two converter stations, each rated 690 MW. One terminal, Des Cantons, is located near Sherbrooke, Quebec, and the other, Comerford, near Monroe, New Hampshire. The Phase I converter terminals were placed in service in October 1986.
The contract for Phase II included three additional converter terminals as well as modifications to the existing ones. The line was extended north from Des Canton over a distance of 1100 km to the 2250 MW Radisson terminal, located within the La Grande hydroelectric generating complex. Furthermore, the line was also extended over a distance of 214 km south from Comerford to a new 1800 MW converter terminal at Sandy Pond, Massachusetts. This extension was taken into full commercial operation in 1990.
In 1992 another terminal was placed in service on the multi-terminal HVDC system. This terminal is rated 2138 MW and located at Nicolet in the Montreal area.
Radisson Converter Station | 
Sandy Pond Converter Station |
Nicolet Converter Station | 
Valve hall in Sandy Pond |
The Comerford and Des Cantons converter stations were originally to have been integrated into the multi-terminal scheme to enable even more operating flexibility, allowing five stations to operate simultaneously. After reassessing the benefits of this additional flexibility, the owners, however, elected to suspend the commercial multi-terminal integration of Des Cantons and Comerford.
| Main data |  |
| Commissioning year: | 1990 - 1992 |
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| Power rating: | 2 000 MW (multiterminal) |
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| No. of poles: | 2 |
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| AC voltage: | 315 kV (Radisson),
230 kV (Nicolet),
345 kV (Sandy Pond) |
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| DC voltage: | ±450 kV |
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| Length of overhead DC line: | 1 480 km |
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| Main reason for choosing HVDC: | Long distance, asynchronous networks |
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