Siemens has introduced a new solution for connecting offshore wind turbines to the grid. Presented at the National Maritime Conference in Bremerhaven, Germany, this DC technology is claimed to enable a cost-efficient and simplified connection of offshore wind power plants far from the coast. The platform housing the transmission technology is much smaller and more compact than before. Previously, these plants have been connected to the grid via large central converter platforms. Siemens is now further developing the transmission technology, enabling a large number of much smaller platforms to be built. The new solution enables a DC cable to connect several of these platforms sequentially in a wind farm, and then route them to an onshore transformer substation. Overall, this solution costs less and is more efficient than the current approach.
The compact design permits encapsulated high-voltage electrical equipment to be used, especially diode rectifier units (DRUs), which are installed instead of the usual air-insulated transistor modules. The volume of the platform structures is reduced by four-fifths, and the weight is cut by two-thirds. As a result, costs are reduced by more than 30 per cent. At the same time, the new solution enables transmission capacity to be increased by one-third, and reduce transmission losses by one-fifth.