A Non-Isolated Coupled-Inductor-Based High-Gain ZVS Bidirectional DC–DC Converter for EV Applications

High-gain bidirectional dc–dc converters are essential for interfacing low-voltage battery packs with high-voltage dc buses in electric vehicle (EV) powertrains. This paper proposes a non-isolated coupled-inductor-based bidirectional dc–dc converter with an integrated active-clamp branch for high step-up and step-down voltage conversion. The proposed topology achieves zero-voltage switching (ZVS) for all high-frequency switches over a wide operating range without requiring bulky resonant tanks or additional auxiliary circuits. In addition, the converter maintains a common ground between the low- and high-voltage sides while employing only three high-frequency active switches, resulting in reduced control complexity and component count. Steady-state operation, voltage-gain expressions, and soft-switching conditions are analyzed for both boost and buck operating modes. A 200-W experimental prototype operating at 100 kHz with 48-V/350-V conversion capability is developed to validate the proposed converter. Experimental results confirm the theoretical analysis and demonstrate peak efficiencies of 97.5% in boost mode and 96.2% in buck mode while maintaining ZVS operation for all active switches.