HVDC BorWin2 is a

high voltage direct current A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...

(HVDC) link built to transmit

offshore wind power Offshore wind power or offshore wind energy is the generation of electricity through wind farms in bodies of water, usually at sea. There are higher wind speeds offshore than on land, so offshore farms generate more electricity per amount of c ...

to the

power grid An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:Kaplan, S. M. (2009). Smart Grid. Electrical Power ...

of the German mainland.Hussennether, V., Rittiger, J., Barth, A., Worthington, D., Dell’Anna, G., Rapetti, M., Hühnerbein, B., Siebert, M., Projects BorWin2 and HelWin1 – Large Scale Multilevel Voltage-Sourced Converter Technology for Bundling of Offshore Windpower, CIGRE Session 2012, Paris, paper reference B4-306. The project differs from most HVDC systems in that one of the two

converter stations Converter may refer to: Electromagnetics *Frequency converter *Voltage converter, another name for **Electromagnetic transformer **Switched-mode power supply **DC-to-DC converter **Power inverter (DC to AC) ***Solar inverter Electronics *Digita ...

is built on a platform in the sea. Voltage-Sourced Converters are used and the total cable length is 200 km. The project was completed by the

Siemens Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...

Prysmian Prysmian S.p.A. is an Italian company with headquarters in Milan, specialising in the production of electrical cable for use in the energy and telecom sectors and for optical fibres. Prysmian is present in North America with 23 plants, 48 in Eur ...

consortium and handed over to its owner,

TenneT TenneT is a transmission system operator in the Netherlands and in a large part of Germany. ''TenneT B.V.'' is the national electricity transmission system operator of the Netherlands, headquartered in Arnhem. Controlled and owned by the Dutch g ...

, in January 2015, becoming the first such project to be completed (the earlier HVDC BorWin1 project, despite having completed construction in 2009, was still not fully in service by that date).

Context

BorWin2 is part of an ambitious programme of providing grid connections to offshore wind parks off the coast of Germany, in the

German Bight The German Bight (german: Deutsche Bucht; da, tyske bugt; nl, Duitse bocht; fry, Dútske bocht; ; sometimes also the German Bay) is the southeastern bight of the North Sea bounded by the Netherlands and Germany to the south, and Denmark and ...

, as part of the German

Energiewende The ''Energiewende'' (; ) is the ongoing transition by Germany to a low carbon, environmentally sound, reliable, and affordable energy supply. The new system intends to rely heavily on renewable energy (particularly wind, photovoltaics, and ...

(Energy Transition) programme. BorWin2 forms part of the ''BorWin cluster'', named after the German island of

Borkum Borkum ( nds, Borkum, Börkum) is an island and a municipality in the Leer District in Lower Saxony, northwestern Germany. It is situated east of Rottumeroog and west of Juist. Geography Borkum is bordered to the west by the Westerems strait ...

. BorWin2 has been built to transport power from the 400 MW Veja Mate (using 6 MW Siemens gearless turbines) and Global Tech 1 wind parks.

HVDC A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...

has been chosen for most of the grid connections because the relatively long distance involved – both from the wind park to shore and from the shore to the nearest suitable connection point to the onshore grid - makes conventional alternating current transmission uneconomic.

Technical aspects

left, The land converter station at Diele.BorWin2 uses Voltage Sourced Converters (VSC) to convert from AC to DC and back again, using 4.5 kV IGBTs as the switching elements. One converter is provided at each end of the link with a DC voltage of ±300 kV and a transmission capacity of 800 MW. The converters, built by

, use the Modular Multi-Level Converter technology, in the symmetrical monopole configuration. Each converter station is equipped with two, three-phase transformers, each rated at 590 MVA (offshore) and 585 MVA (onshore). Each converter valve is equipped with a dry-type valve reactor of 50 mH. The offshore converter is located on the BorWin Beta platform, which was built by

Nordic Yards Nordic most commonly refers to: * Nordic countries, written in plural as Nordics, the northwestern European countries, including Scandinavia, Fennoscandia and the North Atlantic * Scandinavia, a cultural, historical and ethno-linguistic region in ...

Warnemünde (, literally ''Mouth of the Warnow'') is a seaside resort and a district of the city of Rostock in Mecklenburg, Germany. It is located on the Baltic Sea and, as the name implies, at the estuary of the river Warnow. is one of the world's busie ...

. The ''topside'' of the platform is of the ''float-over'' type which is designed to be floated out to the installation site and then jacked up onto the submerged supporting structure using the support legs that are integral to the structure. The topside has a total weight of 12000 tonnes and measures 72.5 m x 51 m x 25 m high. Each of the two 300 kV cables linking BorWin Beta to the onshore substation has a total length of 200 km, of which 125 km is sea cable and 75 km is underground land cable. The cables cross the small island of

Norderney Norderney ( nds, Nördernee) is one of the seven populated East Frisian Islands off the North Sea coast of Germany. The island is , having a total area of about and is therefore Germany's ninth-largest island. Norderney's population amounts ...

and, having reached the mainland, continue, as land cables, to the onshore

converter station An HVDC converter station (or simply converter station) is a specialised type of substation which forms the terminal equipment for a high-voltage direct current (HVDC) transmission line.Arrillaga, Jos; High Voltage Direct Current Transmission, se ...

at Diele. The cables were supplied by

and use extruded

Cross-linked polyethylene Cross-linked polyethylene, commonly abbreviated PEX, XPE or XLPE, is a form of polyethylene with cross-links. It is used predominantly in building services pipework systems, hydronic radiant heating and cooling systems, domestic water piping, ins ...

insulation.

Construction schedule

The BorWin2 project was ordered in 2010. The platform was installed in April 2014. Commissioning was completed in November 2014 and the project was handed over in January 2015.Successful Commissioning Of BorWin2 And HelWin1 HVDC Grid Connections
Realwire.com, 9 February 2015.

References

External links

Description of project
on

website (in German).
Description of project
on

website (in English).
Fact Sheet - BorWin2 HVDC Platform

website.
BorWin 2 HVDC system
{Dead link, date=January 2020 , bot=InternetArchiveBot , fix-attempted=yes , CIGRÉ Compendium of all HVDC Projects. Electrical interconnectors in the North Sea HVDC transmission lines Electric power transmission systems in Germany 2014 establishments in Germany Energy infrastructure completed in 2014

Context

Technical aspects

Construction schedule

See also

References

External links