Development and Research of a New Bidirectional Extended Gain DC–DC Topology with Modularity and Continuous Current

Abstract

A new high-gain modular bidirectional DC-DC converter (BDC) is proposed in this paper, designed to facilitate energy transfer between the high- and low-voltage sides of a DC microgrid. In these applications, the low-voltage side typically consists of an energy storage system, such as lithium-ion battery structures. A step-up DC-DC converter is used to connect other sources, such as photovoltaic panels (PVs) or fuel cells, to the grid, delivering a DC voltage of approximately 300 to 500 volts on the high-voltage side. The proposed converter achieves a high voltage gain by operating in boost mode, utilising an extended quadratic boost ratio. Additionally, in buck mode, the converter can function either as a standard buck converter or as a quadratic buck converter. Furthermore, the low-voltage side of the converter features an inductor, which ensures continuous input current, eliminating the need for additional filters. Furthermore, the converter can be extended by the modular features, and the output voltage gain can be greatly increased. It should be noted that only one power switch is used for the voltage boost state, and the extra modules just include the passive elements. For this converter, the mathematical analysis has been accomplished, and the MATLAB Simulink and experimental results have been considered for a 200-W prototype of the proposed converter to prove its operability.