Optimal design methodology for Dual Active Bridge for Flow battery application

The Dual Active Bridge (DAB) is a popular DC-DC converter for bidirectional power transfer in applications such as the re-emerging technology of flow batteries. For such applications, it is essential to design the DAB for the wide voltage range operation of batteries, specifically focusing on its non-linear characteristics. The existing design methods utilise an optimisation algorithm to minimise the losses of the DAB at various equidistant voltage points in the voltage range. The resulting design is less efficient as it gives too much weight to insignificant operating points. This article proposes a new method that uses the flow battery characteristics to determine the operating points at which minimisation should be performed. The proposed method is validated with simulation results.