AC-DC-AC Power Converters with Novel Approach to Power Factor Correction in Three-Phase Systems

The main goal of this paper is to propose three new three-phase to three-phase ac-dc-ac converters, in which the input side is implemented with three-phase three-level PFC rectifier. This rectifier presents some advantages when compared to the two-level rectifier, i.e.: a) operation with high power level; b) reduced voltage harmonics while operating at lower frequency; and c) better quality in the input current waveform. The proposed topologies can operate either with variable output frequency in applications such as ac drive systems, or with fixed output frequency such as UPS (Uninterrupted Power Supply). Experimental results confirm the topologies feasibility. Authors consider the proposed configurations as potentially feasible industrial solutions for applications requiring high power factor at the grid and low THD in the input current waveform, while independently supplying a three-phase load.