A Zero-Voltage Switching Full-Bridge DC--DC Converter With Capacitive Output Filter for Plug-In Hybrid Electric Vehicle Battery Charging

Abstract

In this paper, a novel zero-voltage switching full-bridge converter with trailing edge pulse width modulation and capacitive output filter is presented. The target application for this study is the second stage dc-dc converter in a two stage 1.65 kW on-board charger for a plug-in hybrid electric vehicle. For this application the design objective is to achieve high efficiency and low cost in order to minimize the charger size, charging time, and the amount and the cost of electricity drawn from the utility. A detailed converter operation analysis is presented along with simulation and experimental results. In comparison to a benchmark full-bridge with an LC output filter, the proposed converter reduces the reverse recovery losses in the secondary rectifier diodes, therefore, enabling a converter switching frequency of 100 kHz. Experimental results are presented for a prototype unit converting 400 V from the input dc link to an output voltage range of 200-450 V dc at 1650 W. The prototype achieves a peak efficiency of 95.7%.