Peak Current Optimization of Hybrid NPC-DAB Converter Ensuring Soft Switching of All the Switches

The electric vehicle charger and battery energy storage system require a dc-dc converter to operate on a wide range of output voltage and power while achieving better efficiency. This digest addresses this issue by presenting a generalized modulation scheme (GMS) possessing five control degrees of freedom (DoF) for modulating a hybrid neutral point clamped-dual active bridge (HNPC-DAB) converter. The particular case of the GMS having four DoFs is identified to enhance the converter performance. The converter model is developed with four control DoFs to derive constraints on converter current for soft-switching. Furthermore, the model is used to reduce the converter peak current (PC), which results in a significant reduction of converter losses. The optimized converter performance (OCP) is validated with the simulation model. Furthermore, the OCP is compared with the modulation scheme in the literature, verifying a significant reduction in PC.