A Two-Stage DC-DC Isolated Converter for Battery-Charging Applications

This paper proposes and analyzes a two-stage dc-dc isolated converter for electric vehicle charging applications, where high efficiency over wide range of battery voltages is required. The proposed conversion circuit comprises first two-output isolation stage with CLLC resonant structure second two-input buck regulator. transformer the designed such that its two output correspond, ideally, to minimum maximum expected voltage be supplied battery. Then, combines provided by previous regulate whole converter. always operated at resonance, only function providing fixed ratios losses, whereas allows regulation voltages. Overall, it shown solution features comprehensively describes solution, including modeling, analyses, design considerations main components (e.g., magnetics, switches), modulation choices. Experimental results are reported considering module prototype rated $10\,\mathrm{k}\mathrm{W}$ , input notation="LaTeX">$800\,\mathrm{V}$ notation="LaTeX">$250\,\mathrm{V}$ notation="LaTeX">$500\,\mathrm{V}$ employing silicon-carbide gallium-nitride semiconductors.