A High-Voltage and Large-Capacity Three-Port DC/DC Converter for Renewable Energy Collection Systems

Offshore wind power has developed rapidly in recent years, it has become an important part of renewable energy, and is gradually developing into the deep sea. Compared with traditional offshore wind farms (OWFs), all-DC wind farms have become a research highlight for offshore power transmission due to their advantages of small size, large capacity and high efficiency. With the large-scale development of OWFs, multi-port DC/DC converters (MPDC) can cost-effectively gather and transmit the wind power scattered in wind farms around the sea to the onshore. In this paper, a high-voltage and large-capacity DC/DC converter MPDC is proposed, each phase circuit of MPDC can be connected to all ports for power conversion, which can realize circuit multiplexing. Besides, the strings in parallel with each input ports to share high current stress, and connected in series to the output port to share the high voltage stress. Taking three ports as an example, the topology structure, operating principle and circuit design of the proposed converter are analyzed. Simulation of MPDC connecting two OWFs with 100MW, 150MW rated power verify feasibility of the proposed MPDC.