The Danish-German Combined Grid Solution (CGS) in the Baltic Sea is the world’s first offshore interconnector to use national grid connections of offshore wind farms to link the transmission systems of two countries.

For this purpose, submarine cables were laid between the offshore transformer stations of the German wind farm Baltic 2 and the Kriegers Flak wind farm in the Danish part of the Baltic Sea.

The German onshore converters for the CGS are housed at the Bentwisch substation near the Baltic port city of Rostock where a double converter system is installed including a back-to-back converter.

This helps balancing the asynchronous transmission systems of Germany and Eastern Denmark: The AC from the Nordic synchronous area is converted into DC and directly back into AC, now adapted to the European synchronous area.

The CGS is a joint project of TSCNET shareholder 50Hertz, one of the four German transmission system operators (TSOs), and TSCNET customer Energinet, the TSO from Denmark.

The operational readiness of the double converter system in Bentwisch marks another important milestone on the way to the commissioning of the entire CGS.

Source: TSCNET