DC Collection for Wind Farms

Abstract

In the US, much of the wind resource is located a significant distance from population centers. Existing AC grids, if available, are weak and incapable of carrying large amounts of wind power. Use of proven HVDC technology using Voltage Source Converters (VSC) to perform the long haul for wind energy offers significant advantages at the system level. If one maintains the existing architecture with 60 hertz ac machines (DFIG or PM) connected in parallel, with another VSC converter station at the wind-farm, then the approach appears to be very expensive. This paper proposes a cost effective approach that is based on a compact and light HVDC architecture where individual turbine output is directly converted to DC, using PM generators, medium frequency transformers and simple power converters.