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Interconnections between Germany (50Hertz) and Poland (PSE)

Scheme of transmission lines between 50Hertz and PSE Scheme of transmission lines between 50Hertz and PSE

Between the transmission networks of 50Hertz and the Polish transmission system operator PSE currently two cross-border power lines exist (see graphic). Both lines are AC lines. The northern interconnector between the substation Vierraden (Germany) of 50Hertz and the substation Krajnik (Poland) of PSE was commissioned in 1987 with a nominal voltage of 220 kV. A second interconnector with a nominal voltage of 380 kV is in operation further in south between the 50Hertz substation Hagenwerder (Germany) and the PSE substation Mikułowa (Poland) since 1999.

A third connection line ("3rd interconnector") between Eisenhüttenstadt (Germany) and Plewiska (Poland) is currently in planning phase. Commissioning is currently envisaged only after 2030, as the West-Polish grid has to be extended first. For more information, please visit:

http://www.50hertz.com/en/Grid-Extension/Onshore-projects/3-interconnector

Construction of Phase Shift Transformers (PST) on the interconnectors between Germany and Poland

In order to increase the regulation possibilities of cross-border power flows 50Hertz and PSE install phase shift transformers (PST) on the two existing interconnectors which are operated in a coordinated manner. After the successful commissioning of the first four PSTs at the Polish substation in Mikułowa in June 2016, the northern interconnector between Vierraden and Krajnik was temporarily taken out of operation in order to upgrade the two substations in Vierraden and Krajnik to 380 kV. 50Hertz is currently installing the first two of a total of four planned PSTs at the Vierraden substation.

In 2018, the interconnector between Vierraden and Krajnik will be reconnected and at the same time the first two PSTs will be commissioned in Vierraden. While the line to Poland is operated with 380 kV, on the German side a link to the existing 220 kV lines will be established as construction of the 380 kV Uckermarkleitung is delayed due to a claim. To realise the link of the 380 kV interconnector in Vierraden, two 380/220 kV transformers will be used as an intermediate step in addition to the two PSTs. With commissioning of the Uckermarkleitung (expected in 2020), these two 380/220 kV transformers will be replaced by two more PSTs. After that, the installation of PST in Vierraden will be completed.

Further information regarding the PST projects of 50Hertz and PSE:

press release: power flow regulation between Germany and Poland

press release: Agreement between Polish and German transmission system operators signed

Pilot and Operational Phase of “virtual Phase Shift Transformer” (vPST) on the interconnectors between Germany and Poland

Commissioning of the first four PSTs in Mikułowa in June 2016 marked at the same time the end of the operational phase of the so-called "virtual Phase Shift Transformer" (vPST), which was previously operated to control unplanned power flows, ensure system security and foster cross-border electricity trading. On 18.03.2014 50Hertz and PSE launched the operational phase of the vPST. Beforehand, the partners tested the vPST mechanism during its pilot phase from 08.01.-30.04.2013 and drew conclusions for the subsequent operational phase. The report prepared jointly by PSE and 50Hertz presents the principles, assignments and most important results of the vPST pilot phase.

Further information regarding the virtual phase shift transformer of 50Hertz and PSE:

press release: energy management through phase shifters

Report on vPST pilot phase experience