환류다이오드의 전압스트레스가 강하된 Soft-Switching Buck 컨버터

초록

This paper presents a buck circuit topology of high-frequency with a single switching device. It solved the problem which arised from hard-switching in high-frequency using a resonant snubber and operating under the principle of ZCS turn-on and ZVS turn-off commutation schemes. In the existing circuit, it has the voltage stress that is almost twice of input voltage in a free-wheeling diode. But in the proposed circuit, it has the voltage stress which is lower than input voltage with modifing a location of free -wheeling diode. In this paper, it expained the circuit operation of each mode and, confirmed the waveform of each mode with simulation result. Also, the experiment result verified the simulation waveform and compared the existing voltage stress of free-wheeling diode with the proposed voltage stress of that. Moreover, it compares and analyzes the proposed circuit's efficiency with the hard-switching circuit's efficiency according to the change of load current.