A soft-switched flyback converter with leakage recovery snubber for class 2 LED driver

Abstract

This work presents a soft-switching flyback converter with active leakage recovery snubber suitable for use in high-performance class 2 LED lamp drivers. The proposed converter enjoys the features of simple circuit structure, improved switching performance, high efficiency and high power density. Transformer leakage energy of the flyback converter is recovered using an active auxiliary circuit, which also helps in soft-switching transition of the switches and power diodes. Switching turn-on and turn-off of its main switch occurs under ZVZCS and ZVS conditions respectively, whereas ZCS turn-on and ZVZCS turn-off of the auxiliary switch are also achieved in this converter. The detailed steady-state operating principle with mathematical equations, design guidelines and loss analysis are presented in this work. Finally, the converter feasibility is thoroughly tested through laboratory experimentation on a hardware prototype. The experimental results have successfully validated the theoretical analysis and real-time behavior of the converter.