Under CopyrightValov, B.B.Valov2022-03-132.8.20162009https://publica.fraunhofer.de/handle/publica/39262010.24406/publica-fhg-392620In the near future the power of 12 out of 21 wind farms in Baltic Sea and North Sea of Germany will be from 1 up to 5 GW. For the connection to the power transmission system on the sea a transformer in this power range will be required but it is not available due to limitation of production facilities. Another problem is the transport of such big units. In this paper the future challenges with power transformers for offshore wind farms are discussed and possible approaches for optimization of number, design and performance are suggested. A new modular design concept and its electrical operation were investigated and the feasibility has been verified by calculations. The proposed approaches showed ways for reduce of weight and volume of transformers as well as for solution of logistic problems.enoffshore wind farmstransformerpower transmissionconference paper