A modular converter topology for offshore wind power generation with minimum decoupling capacitor

Abstract

Wind power generation is one of the most mature and scale of developing new energy generation technology. Using advanced transmission technology to realize future offshore wind power base transmission has become an important direction under the background of future power grid construction and new infrastructure construction. The DC transmission method is mature in technology, but the converter station occupies a large area, and the platform is expensive. This paper proposes a modular converter topology suitable for offshore wind power generation with a minimum decoupling capacitor. The four-port LLCDCX is used as the key component of ripple cancellation, which can eliminate double-frequency power ripple, significantly reduce the volume of the converter and increase the power density. The inverter unit adopts the cascaded H-bridge structure and can be combined to meet the requirements of different levels of occasions. The DC side power decoupling control strategy is proposed, and the simulation results show the accuracy of the control strategy. The proposed topology provides new ideas for the construction of offshore wind power DC grids.