Asymmetrical ZVS-PWM Half-Bridge-Type Switched-Capacitor DC-DC Converter Isolated with Peak Voltage Equal to Vin/2 Switch

Abstract

This paper presents a new power converter topology generated by the integration of the asymmetrical ZVS-PWM dc-dc converter with a switched-capacitor ladder-type commutation cell. Circuit operation and theoretical analysis with emphasis on the soft-commutation process are included in the paper. The main advantage of the proposed converter with respect to the conventional asymmetrical half-bridge dc-dc converter is the reduction of the voltage stress across the power switches to the half of the input dc bus voltage, enabling the utilization of lower voltage rating components. Experiments conducted on a laboratory prototype with 1.4 kW power-rating, 800 V input voltage, 48 V output voltage and 100 kHz switching frequency are included to verify the theoretical analysis and the design methodology. The maximum efficiency of the experimental non-optimized prototype was 93.6%.

Keywords

• Asymmetrical dc-dc converter
• isolated, Pulse Width Modulation
• Switched capacitor
• Zero-Voltage-Switching