AC/AC Single-Phase Three-Leg Dc-Link Converters Based on Three-Level and Two-Level Legs

This paper investigates six three-leg single-phase to single-phase dc-link converters employing three-level and two-level legs. The pulse-width modulation techniques and a control technique that aims at maximizing the utilization of the DC-link voltage are presented. In addition, several relevant characteristics of the converter are addressed, such as voltage capability, harmonic distortion, shared-leg and capacitor currents, and power rating. The features of such converters are compared to the ones of the three-level three-leg converter. Experimental results are presented.