Swepol
Swepol is the name of a 254.05 km long monopolar high-voltage direct current (HVDC) transmission , which connects the power grids of Poland and Sweden .
 
| ||
Location of the two converter stations |
The HVDC Swepol went into operation in 2000. It has an operating voltage of 450 kV and a maximum transmission capacity of 600 MW. It currently has the fourth longest high-voltage submarine cable in the world. In addition to the 239.28 km submarine cable section, the Swepol consists of two land cable sections, one 2.22 km in length in Sweden from the Baltic coast to the converter station in a former quarry in strengnö and one 12.55 km in Poland from the landing point in Ustka to the converter station in Bruskowo Wielkie .
The high voltage cable has a cross section of 2100 mm². In contrast to other monopolar HVDC systems, the SwePol does not use the ground as a return conductor, but separate cables. In the Baltic Sea these consist of two parallel-connected cables with a cross section of 630 mm² and on the land sections of a cable with a cross section of 1100 mm². The cables for the return conductor are designed for a voltage of 24 kV. The grounding takes place in the converter station Bruskowo Wielkie.
Smoothing chokes with an inductance of 225 mH are used in both stations , which are designed as air-core coils with a weight of 27.5 t and are located on the high-voltage side.
Four filters are used as harmonic filters in both stations, which are matched to the 11th, 13th, 24th and 36th harmonic and consist of a series connection of a coil and a capacitor . The filters for the 11th and 13th harmonics can be adjusted by adjusting the inductance value. The filters deliver a reactive power of 95 MVar . A further 95 MVar are available via a capacitor bank.
In both stations, the converter is designed as a twelve-pulse circuit with 792 thyristors and is housed in three 16 m high thyristor towers, which are located in a converter hall .
Eleven cable damage has occurred since operations began, once caused by an anchor and once by a fishing net. A grid disruption resulted in Sweden feeding energy into the Polish power grid. On February 14, 2005 the smoothing reactor burned in the Polish converter station; it then had to be replaced by a new one in a 20-hour campaign. Two fires in the harmonic filters made it necessary to redesign the filter.
Web links
- SwePol Link AB (Swedish)
- SwePol Link HVDC interconnection project. The ABB Group, archived from the original on June 24, 2009 ; Retrieved August 3, 2013 .
- pse-swepollink (English)