A bidirectional DC–DC converter based on a three-winding coupled-inductor and voltage multiplier with improved gain-to-elements ratio

This paper introduces a bidirectional DC-DC converter (BDC) leveraging a three-winding coupled-inductor (TWCI) paired with a voltage multiplier cell. This design has achieved a series of advancements over existing BDCs, including enhanced voltage gain, optimized gain-to-element ratio, improved utilization factor for power switches, and reduced maximum switch voltage (MSV). Furthermore, the proposed BDC ensures continuous input current in boost mode and continuous output current in buck mode, both exhibiting minimal current ripple. This is particularly beneficial for those energy sources that are highly sensitive to discontinuous or pulsating currents. Additionally, the inclusion of a common ground simplifies voltage measurement and sampling processes, which many BDCs lack. Comparative analyses with alternative circuits reveal these merits in key areas, including voltage gain, gain-to-element ratio, switch utilization, and MSV. The paper presents the operational principles of this topology in-depth and substantiates its superior performance with empirical laboratory results.