Kontek
Encyclopedia
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
power grid with the electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
grid of the Danish island Sealand. The name comes from "continent
Continent
A continent is one of several very large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents—they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia.Plate tectonics is...
" and the name of the former Danish
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
power transmission company "Elkraft", which operated the power grid on the Danish islands Lolland
Lolland
Lolland is the fourth largest island of Denmark, with an area of 1,243 square kilometers . Located in the Baltic sea, it is part of Region Sjælland...
, Falster
Falster
Falster is an island in south-eastern Denmark with an area of 514 km² and 43,398 inhabitants as of 1 January 2010. Located in the Baltic sea, it is part of Region Sjælland and is administered by Guldborgsund Municipality...
and Zealand and had the abbreviation "ek". The cable is operated by Energinet.dk
Energinet.dk
Energinet.dk is the Danish national transmission system operator for electricity and natural gas. It is an independent public enterprise owned by the Danish state under the Ministry of Climate and Energy...
in Denmark and Vattenfall Europe Transmission
Vattenfall
Vattenfall is a Swedish power company. The name Vattenfall is Swedish for waterfall, and is an abbreviation of its original name, Royal Waterfall Board...
in Germany.
Kontek is remarkable because, in contrast to similar facilities like Baltic-Cable and Konti-Skan
Konti-Skan
Konti–Skan is the name of high-voltage direct-current transmission line between Denmark and Sweden.-Technical description:...
, 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
Static inverter plant
A static inverter station, also known as an HVDC Converter Station, is the terminal equipment for a high-voltage direct-current transmission line, in which direct current is converted to three-phase alternating current, and, usually, the reverse...
of Bentwisch
Bentwisch
Bentwisch is a municipality in the Rostock district, in Mecklenburg-Vorpommern, Germany, to the east of Rostock. The village has 2.455 inhabitants and covers 14.74 square kilometres...
. It runs 13 kilometers to Markgrafenheide on the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
, 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
Baltic Cable
The Baltic Cable is a HVDC power line running beneath the Baltic Sea that interconnects the electric power grids of Germany and Sweden.The Baltic Cable uses a transmission voltage of 450 kV – the highest operating voltage for energy transmission in Germany...
through the use of a 50-centimeter ramp. The Kontek reaches Falster near Gedser
Gedser
Gedser is a town at the southern tip of the Danish island of Falster in the Guldborgsund Municipality in Sjælland region. It is the southernmost town in Denmark. The town has a population of 809...
, 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
Static inverter plant
A static inverter station, also known as an HVDC Converter Station, is the terminal equipment for a high-voltage direct-current transmission line, in which direct current is converted to three-phase alternating current, and, usually, the reverse...
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.