In this Thesis, the composite converter is modified with the attempts of improving the converter efficiency using series injection. The composite converter was introduced as a DC transformer consisting of a buck, boost, and dual active bridge (DAB) converter that is bidirectional in nature [1]. Few studies since the introduction of the composite converter have attempted to improve the converter design, while the application of the composite converter itself is more common [3,7]. However, studies have been done to improve the performance of the DAB Converter. Series injection is a technique that improves the efficiency of the DAB converter with the use of a series transformer that improves the zero-voltage switching (ZVS) of the DAB. The proposed series injected DAB converter replaces the traditional DAB converter in the composite converter design with the intent of improving the overall composite converter efficiency. The modified circuit is validated via a comparison of converter efficiencies upon a variety of voltage and switching mode combinations modeled via computer simulation
