A High Frequency ZVS Isolated Dual Boost Converter with Holdup Time Extension Capability

Bulky holdup time capacitor prevents further increasing power density of front-end AC/DC converters. Instead of using auxiliary circuits, a high frequency isolated dual boost converter is proposed to reduce holdup time capacitor. ZVS can be achieved for both primary side and secondary side switches. Moreover, low voltage stress on the secondary side devices and simple synchronous rectification control make the topology attractive for low output voltage applications. The converter operates optimally under normal condition with wide input voltage range. Based on theoretical analysis, the proposed converter can reduce holdup time capacitor from 1000 muF to 440 muF with 1200 W output power