Highly Efficient Single-Phase Direct AC-to-AC Converter With Reduced Semiconductor Count

A simple and efficient single-phase direct ac-to-ac converter with the possibility to be utilized as a voltage buck or buck-boost converter is proposed in this article. The proposed converter offers higher efficiency than the competitors with a lower number, of semiconductors. The proposed switching strategy minimizes the high-frequency operation and simultaneous conduction of semiconductors during each mode of operation. Besides a higher efficiency, the other major advantages of the proposed converter are eliminating the risk of input source shoot-through, a lower number, and total rating of semiconductors, defined by switching device power parameter, a lower number and smaller size of reactive components, a better input current quality, and lower filtering requirements. The theoretical claims are confirmed through experiments on a 480-W prototype built in a laboratory.