A Phase-Shifted Full-Bridge DC-DC Converter With Dual Clamping Circuits to Eliminate Voltage Oscillation for Electric Vehicles Charger

This article analyzes the mechanisms of voltage oscillation and clamping and introduces a zero-voltage and zero-current-switching (ZVZCS) full-bridge (FB) dc-dc converter with a wide output voltage range. The voltage oscillation is eliminated in all cases, so the proposed converter achieves the lowest voltage stress and reverse voltage of secondary diodes among all phase-shifted FB (PSFB) converters. Thus, low-voltage-rated diodes with better characteristics can be used to reduce conduction and reverse-recovery loss. Most importantly, FB converters can be used in high-input-voltage applications. Besides, compared with the conventional PSFB converter, the proposed topology has advantages such as no duty cycle loss, no circulating current, and a small output filter. As a result, a high efficiency of 98.5% is achieved. These features make the proposed converter suitable for battery charger applications requiring a wide voltage range, as verified by experimental results from prototypes with a 380 V input and a 200-430 V output voltage range.