A Reconfigurable Converter with Bidirectional Energy Transfer

In the conventional integrated reconfigurable converter (IRC) topology, the battery modules charging mode was implemented using a unidirectional DC/DC buck converter supplied by an external DC source. This paper proposes an enhanced IRC configuration which allows bidirectional energy transfer between the battery modules and the AC grid. The bidirectional energy transfer is facilitated by the IRC DC/DC converter and an H-bridge. During the ‘battery to grid’ mode the active/reactive power control is realized by cooperation of the DC/DC converter operating in the boost mode and the H-bridge in the inverting mode. Conversely, during the ‘grid to battery’ mode, the DC/DC converter operates in the buck mode and the H-bridge as a rectifier. The proposed configuration is compact as the same inductor can be shared between all IRC operating modes. A scaled down prototype of the IRC is implemented with three series-connected battery modules. Presented experimental results verify viability of the proposed configuration.