If necessary, the operator can switch between the DolWin gamma and DolWin alpha platforms and so use an alternative shore connection. This increases the supply guarantee. With its two connected wind farms Merkur and Borkum Riffgrund 2, the converter station has an output of 900 MW - enough to power more than one million homes. To bring electricity generated at sea to the onshore grids requires one thing in particular: a robust cable network with sophisticated contact technology that can withstand the extreme conditions. Pfisterer came onto the project in 2011 to develop the connection for the two sister platforms DolWin alpha and DolWin gamma, and the internal cabling on the platform. During pre-qualification, the company carried out numerous preliminary assessments for its solid-insulated pluggable connection system CONNEX in combination with highly flexible 155 kV Feltoflex cable. This system successfully passed the contact ageing test per IEC 61238-1 and electrical testing under IEC 60840 section 12.4.
Around 6,500 metres of Feltoflex cable is now connected to the CONNEX cable connectors, installed by a team of experienced PFISTERER experts in the dry dock at Warnemünde, as well as 80 km distant in the North Sea under extreme offshore weather conditions. With complicated routings requiring extra planning and organisation, this was an incredibly challenging task. But it was completed on time thanks to easy-to-install, low-maintenance CONNEX cable connectors together with PFISTERER's expertise and precision.
- HV offshore cable system for voltages up to 170 kV, for DolWin gamma AC/DC converter Station
- First and so far only system certified for offshore use
- Specially developed HV-CONNEX contact connector for flexible cables up to 800 mm²
- Installation of 6,500 m cable with challenging Routing
- World’s longest 155 kV bridge connection between two offshore platforms