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,F 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 300W and a switching frequency of 180 kHz, the current noise level of the input current decreased by similar to 30 dB at a frequency range of 2.5-48 MHz, and the power-conversion efficiency increased by similar to 7.5% for both the MOSFET and IGBT switches. Also, the temperature of switch was stabilized at similar to 60 degrees 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.