Study on Distributed Power-Collection and Cascaded Boosting-Voltage Topology and Strategy for Offshore DC Station

Different from traditional concentrated power-collection and boosting-voltage (CPCB) topology adopted by HVDC station, this paper adopts a distributed cascaded (DPCB) for offshore DC station to collect power boost voltage, which consists of multiple single active bridges (SABs). It has merits strong DC-voltage boosting ability, low design difficulty cost, system error rate. Three aspects are studied as follows. First, DPCB with its circuit equations is deduced step step, operational mechanism analysed under phase-shifting control method further. Second, PI strategy designed based on small signal model, performance analyzed Bode diagram. Third, fault tolerance predicted ratio keep breakdown when some SABs generators out order, enormous difference occurs due the factors wind turbine location windward. Finally, feasibility effectiveness verified experiment results.