DC-DC Boost Converter의 스위칭 손실 저감을 위한 Passive Snubber 연구

DoctorThis thesis presents a passive snubber for MOSFET and IGBT in a dc-dc boost converter. The snubber consists of one inductor, two capacitors, and two diodes. It improves the power-conversion efficiency significantly by providing zero-current turn-on and zero-voltage turn-off conditions for a switch, without increasing the voltage stress of a switch. When the snubber was adapted to the conventional dc-dc boost converter and tested at an output power of 300 W and a switching frequency of 180 kHz, the current noise level of input current decreased by ~ 30 dB at a frequency range of 2.5 MHz – 48 MHz, and the power-conversion efficiency increased by ~ 7.5 % for both MOSFET and IGBT switches. Also, the temperature of switch was stabilized at ~ 60 °C, while the IGBT failed in the conventional boost converter. These experimental results show that the proposed snubber is useful for solving the reliability problem of boost converters