Increase of the Efficiency for a Solar Renewable Source Using a Soft Switched DC-DC Boost Converter

An important role in the solar renewable energy sources play a DC-DC power converter that transforms the electric energy provided by a photovoltaic (PV) system in DC energy to be used for DC loads or to be stored in high capacity battery. This paper presents a new type of active snubber for DC-DC boost converters that can be used in solar renewable sources. The main purpose of this new circuit is to assure a soft turn-off switching of the power switch in a switched mode boost power supply. The efficiency of the switched mode power supply is negatively influenced by the hard switching of its power semiconductor devices. This effect is easier observed in power supply that uses IGBTs as main power switches. The active snubber presented in this work offers a soft switching at the turn-off of the IGBT. The whole energy accumulated by the proposed snubber in the first part of an operation cycle is transferred to the load in the last part of the operating cycle. The simulation results are in very good agreement with the theoretical analysis of the active snubber. This paper also presents experimental results that validate the discussed operation principle.