A Bidirectional DC-DC Bipolar Converter for Power Transmission Network

In this paper, a DC-DC bidirectional multi-port bipolar converter for DC power transmission network is proposed. Compared with a conventional DC-DC converter, the proposed converter have high efficiency, hence serving as a much more suitable counter-part for a DC power system. The proposed bipolar converter can further reduce the cost of the transmission network as both wires connected to the network can conduct power, doubling the transfer ratio of a unipolar transmission network. As a result, the overall transmission efficiency is improved. A 6-port DC-DC converter is designed and simulated in this paper, supporting 04 inputs (03 renewable energy resources and 01 energy storage system), and 02 bipolar output ports. A PI control scheme is also design to regulate the output voltages in case of any uncertainty (varying input or load). To validate the converter structure and theoretical concepts, the proposed converter is simulated in MATLAB/Simulink environment.