Coupled-inductor AC-to-AC converters having improved input power factor, simple control, and variable output frequency

The main goal of this paper is to propose three single-phase AC-to-AC converters based on an improved version of the AC-DC Nabae converter. The proposed topologies improve input power factor and input current waveform without any complicated switching modulation, such as pulse width modulation, or feedback control. These topologies can operate with either variable output frequency or fixed output frequency. The main characteristics of the proposed configurations are presented and experimental results verify the theoretical studies.