A Parallel-Resonant Isolated Bidirectional DC-DC Converter with Low Current Ripple for Battery Storage Systems

In this paper, a parallel-resonant isolated bidirectional DC-DC converter with low current ripple and high voltage gain is proposed for the battery storage systems. In the low voltage side, the interleaved boost unit is employed to reduce the current ripple for improving the lifetime of battery. And the parallel resonant capacitor of transformer is used to achieve the soft-switching operation and recycle the energy of leakage inductance for improving efficiency. In the high voltage side, the dc-blocking capacitor is applied to increase voltage gain by reducing the voltage on the transformer. The proposed converter can achieve high conversion ratio with high efficiency. Moreover, it only contains four switches. Operation principle analysis and parameters design of the proposed converter are discussed in detail, which are validated by simulation. Finally, a 1kW experimental prototype is built to verify the advantages of the proposed converter.