Electrical collection system options for large offshore wind farms

The work presented is part of the EC FP6 DOWNVIND project activities, which focus on the requirements and implications of very large offshore wind farms. A comparative analysis of various design options for the electrical collector system of large offshore wind farms is presented, and the advantages and disadvantages in terms of their steady-state performance and economics are discussed. The case under consideration is that of a proposed 1-GW wind farm located off the northeast coast of Scotland. The impact on power losses and voltage level changes on the collector system busbars are investigated under various operating conditions. Contingency conditions of losing one of the cables to the hub end are also explored for collector system designs with redundant cables. Finally, the authors introduce an alternative design, based on conceptual ringed arrangements, and its advantages are illustrated and discussed