This paper investigates a single-phase ac-dc-ac topology composed of two three-leg modules parallel-connected at rectifier side and series-connected at inverter side. This converter is appropriated for applications as uninterrupted power supply, unified power quality, as well as for conversion systems in which the output voltage is twice the input voltage, a common scenario in Brazil where the electric distribution system uses single-phase voltages that vary between 110 V(rms) and 220 V(rms) in different regions. System model and control strategies are developed. An interleaved pulse width modulation techniques (PWM) based on two and four carriers are presented. Compared to conventional structures, the proposed structure permits to decrease the voltage harmonic distortions and the current and voltage rating of power switches that can be turned into semiconductor losses reduction. Simulation and experimental results for validation proposes are presented.
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