A multicell Dual-Active Bridge converter for increasing the reliability of power supply in a DC microgrid

This paper presents a multicell Dual-Active Bridge (DAB) converter that can increase the reliability of the power supply in a dc microgrid. The main feature of the proposed interconnection scheme is that it can supply power to a load even if one of its converters is taken out of operation or fail. This is accomplished because each cell is composed by a number of DAB converters interconnected in parallel in both of its ports, in that manner, when one of its converters is driven not to process power or is subject to a failure the others share that power keeping the load supplied. Then, in order to achieve a high voltage gain with lower voltage stresses on the switches, the cells are interconnected in parallel in one of its ports (low-voltage bus) and in series in the other (high-voltage bus) implementing a solidstate transformer (SST).