A Passive Lossless Snubber Applied to the AC-DC Interleaved Boost Converter

High switching frequency operation of static power converters is often required to reduce size, weight, and electromagnetic interference levels, at the cost of increased switching losses and reduced efficiency. Switching losses include the current and voltage overlap loss during the switching interval and the capacitance loss during turn-on. Recently, the use of passive soft switching methods has been emphasized as a better alternative to active methods, mainly because they do not require extra switches or additional control circuitry. This paper proposes a passive lossless snubber applied to the interleaved boost converter. The use of a soft commutation cell causes the main switches to be turned on and off under null current and null voltage conditions, respectively, as high efficiency results over the entire load range. The theoretical analysis including the description of the operating stages and the design procedure are included. Experimental results on a 2 kW prototype are presented and discussed to validate the proposal.