A Non-Isolated Bidirectional Multiport Converter for Interfacing Hybrid Energy Sources in LVDC Grid

This paper presents a new buck-boost-type bidirectional multiport converter for LVDC systems to achieve efficient power conversion between energy sources. Based on the differential converter technology, the resultant integrated three-port converter is able to handle bidirectional power flow, enhance buck-boost converter operation range, support a wide range of inputs and outputs, and come with a simple circuit and control structure. Through an adaptive interleaving control strategy, size reduction of all the passive components is able to achieve. Thus, a high efficiency and high power density interface is developed. This paper presents a detailed system analysis of the proposed solution, including circuit operation, steady-state characteristics, and design implementation. To analyze the solution feasibility, the performance of the proposed converter is experimentally verified on a 24 V - 120 W solar-battery system prototype. Both steady state and dynamic characteristics are shown in good agreement with the theoretical knowledge.