Design and implementation of a current-fed dual active bridge converter for an AC battery

Home battery has become more and more popular in which the AC battery is a trending product along with the AC-coupled system. The energy conversion of an AC battery commonly consists of a two-stage power converter to flexibly connect to the wide-range input battery voltage and different grid or load types. This study specifically concentrates on the DC/DC stage which plays an important role in transferring power with the battery. In addressing the need for isolation, bidirectional power flow, and limited battery current ripple, the Current-fed Dual Active Bridge (CFDAB) structure is chosen for this stage. This paper presents a comprehensive design for the CFDAB converter for an AC battery application, especially a technical solution focusing on zero voltage switching is applied to increase the efficiency of the converter. Finally, an experimental prototype is carried out to validate the performance of the CFDAB converter in both two modes of the power flow.