A Six-Leg AC-DC-AC Single-Phase Three-Wire Power Converter

This paper presents a single-phase three-wire power converter using a six-leg converter. The proposed converter is an alternative for these systems since it has better power quality and switches with a reduced voltage rating compared with other solutions presented in the literature. The converter can supply the loads with constant amplitude and frequency, even under unbalanced loads, and the grid current is sinusoidal and has a high power factor, even supplying non-linear loads. These characteristics make the proposed converters suitable for applications such as line conditioners and uninterruptible power supplier. Furthermore, the pulse-width modulation (PWM) technique is proposed to generate the pole voltages of the converters, so that the output voltages have high power quality. The proposed six-leg converter is compared to a conventional five-leg converter from simulated results for evaluating the semiconductor losses and harmonic distortion. Simulation and experimental results are provided to verify the operation of the proposed system.