Prysmian Group announced recently the successful commissioning of the High Voltage Direct Current (HVDC) offshore grid connection project HelWin2 realized off the North Sea coast of Germany in a contract with the Dutch-German transmission system operator TenneT.
Prysmian secured this project in July 2011 as one of several contracts awarded to consortia between the Group and Siemens Energy for the grid connection of offshore wind farms to the mainland. “We are proud to deliver on time such a highly strategic project for the German power grid” says Massimo Battaini, SVP Energy Project at Prysmian Group. “The Prysmian/Siemens consortium is the first to complete such a German offshore grid connection within the agreed timeframe”, he added.
HelWin2 now links the offshore wind park Amrumbank West with a 690 MW cable connection operating at the highest commercially available voltage of ±320 kV DC, along a total route of 130 km (85 km submarine and 45 km land) to the mainland Germany land converter station in Büttel, north-west of Hamburg and is ready to start commercial operations.
HelWin2 uses extruded HVDC cable technology from Prysmian together with Siemens HVDC Plus converter technology at the offshore platform and onshore stations. Prysmian Group has also installed the 155 kV HVAC submarine cables, which connect the converter platform HelWin Beta to the respective individual offshore wind farm transformer platforms.
In addition, HelWin Beta has been connected to the neighbouring platform HelWin Alpha by ways of Prysmian’s Feltoflex HV 155 kV, a new generation of high voltage, rubber insulated cable systems that combine the Group’s extensive expertise in MV heavy duty cable systems with the specific application requirements for mobile interconnections between 2 platforms into a full turn-key ultra-flexible cable system easy to lay even in the harshest climate conditions.
The completion and hand-over of this important project re-affirms the Group’s continued successful relationship with TenneT who have awarded Prysmian the submarine and land cable systems for a total of six HVDC grid connection projects in recent years. HelWin2 is the fourth grid connection to be handed over this year following the BorWin2, HelWin1 and SylWin1 projects commissioned in late January, early February and late April, respectively. Prysmian is currently implementing also the HVDC cable systems for the DolWin3 and BorWin3 projects.