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A new zero-voltage switching full-bridge dc–dc converter for battery charging is proposed in this paper. The proposed isolated dc–dc converter is used for the dc–dc conversion stage of the electric vehicle charger. The primary switches in dc–dc converter turn-on at zero voltage over the battery-charging range with the help of passive auxiliary circuit. The diode clamping circuit on the primary side minimizes the severity of voltage spikes across the secondary rectifier diodes, which are commonly present in conventional full-bridge dc–dc converters. The main switches are controlled with an asymmetrical pulse-width modulation (APWM) technique resulting in higher efficiency. APWM reduces the current stress of the main switches and the circulating losses compared with the conventional phase-shift modulation method by controlling the auxiliary inductor current over the entire operating range of the proposed converter. The steady-state analysis of auxiliary circuit and its design considerations are discussed in detail. A 100-kHz 1.2-kW full-bridge dc–dc converter prototype is developed. The experimental results are presented to validate the analysis and efficiency of the proposed converter. [ABSTRACT FROM PUBLISHER]

An efficient power converter system plays a significant role in the design of battery charging systems for electric vehicles (EVs). In this paper, a new zero-voltage and zero-current switching (ZVZCS) full-bridge dc–dc converter is proposed to reduce the power conversion losses. The proposed converter incorporates a new asymmetrical pulse width modulation (APWM) gating technique for the dc–dc conversion stage in the battery charging system. The proposed dc–dc converter topology achieves zero-voltage switching (ZVS) for all the active switches and near zero-current switching (ZCS) for low-side active switches throughout the charging range of the battery. The proposed APWM technique can reduce the switching and conduction losses compared to the conventional phase-shift modulation (PSM) gating technique. The auxiliary inductance required to ensure ZVS with APWM can also be reduced compared to PSM. Analysis, design, and implementation of the proposed APWM ZVZCS full-bridge dc-dc converter are discussed in this paper. A 100-kHz 1.2-kW laboratory prototype is developed and the experimental results are presented. The results validate the analysis and performance of the proposed converter. [ABSTRACT FROM AUTHOR]