The German company
TenneT Offshore GmbH, formerly transpower stromübertragungs gmbh, has awarded a contract to ABB to supply an 800 MW transmission link that will connect offshore wind farms located in the cluster DolWin1 (Borkum West II wind farm, 400 MW, plus future unnamed wind farms) in the North Sea to the German grid.
The wind farms will be connected with AC cables to the HVDC converter station based on a offshore platform situated in the North Sea and further through 75 km of DC sea cable and 90 km of land cable to the HVDC onshore station at the grid connection point at Dörpen/West.
The transmission system has a total capacity of 800 MW at ±320 kV. The HVDC Light system that will be used offers numerous other environmental benefits, such as neutral electromagnetic fields, oil-free cables and compact converter stations, and is ideal for connecting remote wind farms to mainland networks without distance limitations or constraints on the grid. The system features the latest generation of ABB power semiconductors. The increased performance ensures a higher availability and lower losses of the entire system.
ABB is responsible for system engineering including design, supply and installation of the offshore converter (including the platform), sea and land cable systems and the onshore converter station.
The land cables will be laid underground, thus minimizing environmental impact.
| Main data |  |
|---|
| Commissioning year: | 2013 |
| Power rating: | 800 MW |
| No of circuits: | 1 |
| AC Voltage: | 155 kV (Platform DolWin Alpha),
380 kV (Dörpen/West) |
| DC Voltage: | ±320 kV |
| Length of DC submarine cable: | 2 x 75 km |
| Length of DC underground cable: | 2 x 90 km |
| Main reason for choosing HVDC Light: | Length of land and sea cables. |