Kontek

The Kontek is a 170 kilometer long, monopolar 400kV DC-cable for the interconnection of the German power grid with the electricity grid of the Danish island Sealand. The name comes from "continent" and the name of the former Danish power transmission company "Elkraft", which operated the power grid on the Danish islands Lolland, Falster and Sealand and had the abbreviation "ek".

Kontek is remarkable because, in contrast to similar facilities like Baltic-Cable and Konti-Skan, all land sections of the 119-kilometer line on Falster, Sealand and Germany are implemented as underground cable. This unusual measure, which raised the construction costs of Kontek significantly, was made for practical rather than technical reasons. Obtaining permission for building overhead cables can take a long time, and hence underground cables were used in order to ensure it was completed on schedule.

The Kontek cable begins in the static inverter plant of Bentwisch. It runs 13 kilometers to Markgrafenheide on the Baltic Sea, where a 43 kilometer submarine cable section to the island of Falster begins. In this section, the Kontek crosses the high-voltage DC Baltic Cable through the use of a 50-centimeter ramp. The Kontek reaches Falster near Gedser, and crosses the island via 50 kilometers of underground cable. Subsequently, a 7 kilometer submarine cable section then crosses the sea between Falster and Sealand. A 53 kilometer land cable on Sealand follows, which ends at the static inverter station in Bjaeverskov.

The Kontek can transfer maximally 600 megawatts and has been in service since 1996.

The high-voltage cable of the Kontek is implemented as paper-isolated oil-filled cable with two copper conductors with a cross section of 800 mm² permanently joined in parallel. For better monitoring of the oil, the land sections of the Kontek cable are divided in sections of approx. 8 kilometers, which are separated by oil-impermeable sockets from each other. In the proximity of these sockets - at some distance from the cable route - there are automatic stations for the monitoring of the oil pressure, the oil temperature and other operating parameters of the cable. For practical reasons, the 45 kilometers long submarine cable section through the Baltic Sea between Germany and Denmark was implemented as a single oil-filled section without sockets. As electrode cables of the Kontek, on the German and on the Danish side, commercial plastic-isolated 17kV-cables are used.

The static inverter station in Bjaeverskov was attached to an existing substation for 380kV/110kV. For the construction of the static inverter plant in Bentwisch a new construction site was chosen even though only one kilometer north there is still the old 220kV/110kV-substation which was built in the GDR. In 2002 the static inverter station in Bentwisch was extended to a 380kV/110kV-substation and connected by a 110kV-line to the old 220kV/110kV-substation.

External links

* [http://www.abb.com/global/abbzh/abbzh251.nsf!OpenDatabase&db=/global/gad/gad02181.nsf&v=17EA&e=us&m=100A&c=C1256D71001E0037C125683400212B1A Kontek HVDC Interconnection (ABB)]
* [http://www.transmission.bpa.gov/cigresc14/Compendium/KONTEK.htm KONTEK HVDC Scheme]
* [http://maps.google.com/maps?t=k&ll=54.100693,12.214608&spn=0.002674,0.007317&om=0 Bentwisch Converter]
* [http://maps.google.com/maps?t=h&om=0&ll=55.449269,12.001104&spn=0.022051,0.058537 Google Maps: Bjaeverskov Converter]
* [http://www.kontek.com.tr/ Kontek Construction Company]