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It is well known that there is an increasing demand for bidirectional DC–DC converters for applications that range from renewable energy sources to electric vehicles. Within this context, this work proposes novel DC–DC converter topologies that use the three-state switching cell (3SSC), whose well-known advantages over conventional existing structures are ability to operate at high current levels, while current sharing is maintained by a high frequency transformer; reduction of cost and dimensions of magnetics; improved distribution of losses, with consequent increase of global efficiency and reduction of cost associated to the need of semiconductors with lower current ratings. Three distinct topologies can be derived from the 3SSC: one DC–DC converter with reversible current characteristic able to operate in the first and second quadrants; one DC–DC converter with reversible voltage characteristic able to operate in the first and third quadrants and one DC–DC converter with reversible current and voltage characteristics able to operate in four quadrants. Only the topology with bidirectional current characteristic is analysed in detail in terms of the operating stages in both nonoverlapping and overlapping modes, while the design procedure of the power stage elements is obtained. In order to validate the theoretical assumptions, an experimental prototype is also implemented, so that relevant issues can be properly discussed. [ABSTRACT FROM PUBLISHER]

Inverters are required to convert the dc power from photovoltaic panels to ac. In grid connected inverters, the ac output is directly fed into the electric grid. In this paper, a high-frequency transformer based inverter topology is presented. This leads to a very compact inverter. The modulation of this inverter with a lossless snubber circuit is proposed. Proposed modulation eliminates the over-voltage spikes due to transformer leakage inductance. Commutation of the leakage inductance energy with this modulation is also discussed. The performance of the inverter with the proposed modulation is validated using simulation and experimental results. [ABSTRACT FROM AUTHOR]