HVDC close coupling
An HVDC short coupling , also known as an HVDC short coupling , direct current coupling (GK) or as a direct current short coupling (GKK), in English back-to-back station with the abbreviation B2B , is a system for high-voltage direct current transmission in which Both converters are on the same area, usually even within the same building, and the length of the direct current line is therefore only a few meters. HVDC close couplings are used for the electrical connection of power grids, each with alternating current or three-phase alternating current operated.
The area of application is the coupling of networks with different network frequencies between 60 Hz and 50 Hz as in Japan with the Higashi-Shimizu Frequency Converter or in Saudi Arabia with the GKK Al Fadhili . In addition, HVDC short coupling systems are used to couple networks with different frequencies and number of phases as a replacement for traction current converters with rotating machines. Another area of application is the coupling of asynchronous three-phase networks , such as the Vyborg HVDC close coupling located in Russia , which connects the Russian electricity network with the Finnish network. HVDC close couplings are also widespread in the USA, as there are four asynchronous interconnected networks (continental USA with Canada, but without Alaska and Hawaii). In Central Europe, GKK Etzenricht , GK Dürnrohr and GK Wien-Südost were in operation until 1995/96 , which became superfluous due to the synchronized connection of the Western and Eastern European power grids.
In contrast to HVDC transmission lines, the DC voltage in the intermediate circuit can be selected to be lower in HVDC short couplings due to the short cable length ; a DC voltage in the range from 70 kV to 150 kV is typical. They are always chosen in such a way that the voltage remains as low as possible in order to keep the converter hall as small as possible, but always so high that no parallel connection of rectifiers is necessary for maximum transmission power .
See also
Web links
- High voltage direct current transmission. Proven Technology for Power Exchange (PDF; 3.7 MB), Siemens, 2008 (technical application note; engl.)
Individual evidence
- ↑ Archived copy ( Memento of the original dated August 11, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
