Bidirectional full-bridge converter with hybrid phase-shift control and resonant active clamp circuit for V2G applications

초록

This paper presents a bidirectional full-bridge DC-DC converter, designed for vehicle-to-grid (V2G) applications, that features a novel resonant active-clamp architecture. The proposed design significantly reduces the voltage stress across the clamp capacitor while preserving the core functionalities of conventional active-clamp circuits. This is done by suppressing oscillatory voltages across the rectifier diodes and eliminating the freewheeling circulating current. The converter achieves soft-switching conditions by integrating a resonant operation between the clamp capacitor and the leakage inductance of the transformer and employing a hybrid control strategy that combines phase-shift modulation with active-clamp switching. Specifically, it enables near-zero current switching (ZCS) for the leading-leg switches and suppresses reverse recovery currents in the rectifier bridge. Full-range zero-voltage switching (ZVS) for both leading and lagging legs is attained through a magnetizing current that remains stable despite load fluctuations. A 3.3 kW experimental prototype operating with a 400 V DC link and a battery voltage range of 250-420 V validates the proposed design. Test results confirm high efficiency, achieving 98.2% during charging (buck mode) and 97.6% during discharging (boost mode).

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