Evaluation and selection of AC transmission lay-outs for large offshore wind farms

This paper studies different energy transmission solutions for AC offshore wind farms. This transmission of energy is based on AC submarine cables that present a strong capacitive behavior. Therefore, an analysis is necessary to determine transmission characteristics such as, the number of submarine cables, voltage or rated power. For that purpose, three different transmission configurations will be considered: unique HVAC, various HVAC and MVAC, combined with three submarine cables of different characteristics. By using a design procedure, it is shown that based on the electric characteristics provided by the manufacturer of the submarine cable, it is possible to determine the most efficient energy transmission solution, from the perspective of the submarine cable. Different variables will be taken into account, including transmission current, active power losses, the cost of the transmitted energy and the reactive power compensation required. In addition, the consequences of the selected transmission solution to other more general aspects of the wind farm such as, necessity of the offshore platform or local inter-turbine network are also discussed.