Research on two current-fed isolated bidirectional DC/DC converters for the battery energy storage application

High voltage gain and low current ripple on the low-voltage side can be achieved by both the new isolated bidirectional DC/DC converter based on the Cuk converter(I-DCuk-BDC) and the existing current-fed half-bridge converter(I-DBoost-BDC), so both are suitable for the battery energy storage system. Based on the analysis of the operating principles, the power transfer characteristic, the soft-switching ranges are analyzed, and the power losses are compared in terms of the 48V/400V battery energy storage application. The analysis results reveal that the power loss of the I-DBoost-BDC is less than that of the I-DCuk-BDC, which means the I-DBoost-BDC is superior to the I-DCuk-BDC in this application. The good characteristics of the I-DBoost-BDC has also been verified by the simulation and experimental results.