Hybrid DC–DC Converter With Phase-Shift or Frequency Modulation for NEV Battery Charger

This paper suggests a new hybrid dc-dc converter for a neighborhood electric vehicle battery charger. The proposed converter is based on the conventional phase-shift full-bridge (PSFB) converter with center-tap rectifier. By integrating an LLC series resonant converter into the conventional PSFB converter, the proposed converter has many advantages like wide soft-switching range without duty-cycle loss, zero-current-switching operation of rectifying diodes, minimized circulating current, reduced size of filter inductor, and much better transformer utilization than before presented hybrid dc-dc converters. The proposed converter can be modulated in phase-shift manner or frequency variation. The feasibility of the proposed converter has been verified with the experimental results under an output voltage range of 36-72 V dc at 1 kW.