Design of a novel modular energy conversion scheme for DC offshore wind farms

Offshore wind farms provide benefits over onshore farms in terms of the amount of generated energy and environmental impact. Cost efficient energy transmission is one of the challenges of those installations. In this context direct connection of parallel connected DC wind turbines to the transmission line is a promising solution. Modular DC-DC converters are an attractive solution for the direct connection of the DC wind turbines to the transmission line. In addition, the phase-shifted full-bridge converter (PSFB) is a good candidate to form simple, efficient and reliable high voltage modular DC-DC converters for offshore DC networks. This paper proposes a novel energy conversion scheme for the direct connection of the DC wind turbines to the transmission line. Design criteria for the phase-shifted full-bridge converter and the medium frequency transformer are described and a modular energy conversion scheme is sized to operate with 10MW offshore wind turbines and 300kV transmission voltage.