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