Integration of large sea-based wind parks-how much power electronic devices are needed in order to avoid power quality problems on the grid?

Wind turbines affect the power quality on the grid to which they are connected. A very attractive solution, which eliminates the power quality problem, is to use a variable speed wind turbine, equipped with a power electronic converter. This paper describes the Bockstigen wind park 3 km off the coast of Gotland which is connected to the AC grid. For wind park to shore distances of over 20 km a DC cable link may be a better option. The invention of the HVDC Light concept where transistors are used as power electronic valves have made DC-links interesting for lower power levels, down to a few MW. The power converter options for the Bockstigen and other wind parks are briefly discussed.