A Dynamically Reconfigurable Multiactive Bridge Converter With Extended Topology-Level Decoupling

The cross-coupling effect and complicated control present significant challenges when implementing multiport dc-dc converters such as those enabled by multiactive bridge (MAB) converters. These challenges are typically addressed through additional control layers for implementing power flow decoupling functionality. Besides various control-level methods, the coupling effect can also be mitigated at the hardware level. Designing one of the ports with a small series inductance and feeding it with a rigid voltage source can enable decoupled power transfer without control complexities. However, a failure in the rigid voltage source of that port causes the cross-coupling to reappear. This article proposes a dynamically reconfigurable bridge that can maintain decoupled power flow when the main low-inductance port fails or is islanded. In this approach, a reconfigurable bridge requires two additional switches to bypass the external inductor during failure. The operating principles of the proposed approach are discussed, and its decoupling performance is compared with conventional control-level decoupling and a coupled MAB. The modulation technique is also adapted and implemented to achieve the desired performance. The effectiveness of the proposed solution is validated through testing on a 4kW SiC-MOSFET-based four-port experimental setup.