Pfisterer has been awarded a contract to connect two converter stations within the 900MW DolWin3 offshore wind high voltage direct current (HVDC) link in the German North Sea.

substation

Under the contract, Pfisterer will provide the 250m high-voltage cable link featuring a highly flexible 155kV Feltoflex cable with a conductor cross section of 800mm².

Pfisterer will be responsible for laying all the high-voltage and medium-voltage cable systems within the platform, as well as the cables on the connecting bridge.

The link will be the world’s longest connection between two offshore platforms, the company said.

Through the connection between the DolWin gamma and DolWin alpha platforms situated 80km offshore, the operators will be able to switch over between the converter stations when required.

Pfisterer HV cable projects project manager Vukasin Basara said: "One particular challenge is laying the 4.5km-long, high-flexibility Feltoflex HV cable. For this purpose, we have developed an extraordinary concept.

"The cable is routed from the upper deck of the DolWin alpha platform at a height of 35 meters by means of a rising ladder rack and a bridge of about 30 meters in length, to the DolWin gamma platform."

Pfisterer has already commenced the onshore work to equip the converter station with medium-voltage cable systems. The HVDC offshore connection is scheduled to be completed by 2017.

Pfisterer director of sales for cable accessories and systems Eduardo Santana said: "The DolWin3 order is consolidating our position as the leading manufacturer of cable assemblies in the offshore wind energy sector, as well as our expertise and ability to offer complete integrated systems."

The DolWin3 project, which is expected to cost over €1bn, will link the North Sea wind farms to the mainland supergrid.


Image: Pfisterer will connect two offshore wind power converter stations. Photo: Courtesy of PFISTERER Holding AG.