Offshore Wind Power Transmission Scheme Based on New Topology

In this paper, a novel offshore wind power highvoltage dc (HVDC) transmission scheme is proposed, which directly obtains the HVDC by the cascaded wind turbine AC/DC converters. Different from the traditional series scheme, the proposed topology and control logic enable dynamic configuration of series or parallel operation states among different AC/DC converters of wind turbines according to their DC voltage deviations and the requirement of onshore HVDC converter voltage level. This novel scheme can simplify the system structure and flexibly configure different levels of DC voltage. Moreover, it has lower switching frequency than existing DC/DC switching devices, which can effectively reduce the loss and improve the efficiency of the system, thus achieving good balance between economy and flexibility. A 20MW wind farm is built in MATLAB/SMULINK and the simulation results verify the feasibility of the scheme.