An Offshore Wind Generation Scheme With a High-Voltage Hybrid Generator, HVDC Interconnections, and Transmission

A new offshore high-voltage dc (HVDC) wind generation scheme is proposed in this paper. The scheme implements a high-voltage hybrid generator (HG) as well as HVDC interconnection and transmission systems. The turbine power train of the proposed system is compared with a typical system installed in a commercial wind farm. The analyses demonstrate improvements in system losses and, hence, efficiency, power-train hardware, including cable system mass and, importantly, a reduction in major component count and installed power electronics in the nacelle and turbine tower, features that lead to reduced capital cost and maintenance. The resulting power conversion system is more simplified and more amenable to higher voltage implementation since it is not constrained by existing state-of-art power-electronic voltage source converter structures. Voltage control is facilitated via dc/dc converters located away from the turbine tower. To demonstrate the HG operational concept, measured results from a low-power laboratory prototype HG system are compared with analytical results and show good agreement.