Passive Snubber for Reducing Switching-Power Losses of an IGBT in a DC–DC Boost Converter

A passive snubber for an IGBT in a dc-dc boost converter is proposed. 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 an IGBT, without increasing the voltage stress of an IGBT. 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 the input current decreased by ~30 dB at a frequency range of 2.5-48 MHz, and the power-conversion efficiency increased by ~7.5% for both the 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.