THREE LEVEL SINGLE-PHASE SINGLE STAGE AC/DC RESONANT CONVERTER WITH A WIDE OUTPUT OPERATING VOLTAGE RANGE

넓은 출력 전압제어범위를 갖는 3레벨 단상 단일전력단 AC/DC 컨버터

In this paper, a single-phase single-stage three-level AC/DC converter with a wide controllable output voltage is presented. It integrates a PFC converter and a three level DC/DC converter into one. The proposed converter operates at a fixed frequency and provides a wide controllable output voltage ($200V_{dc}-430V_{dc}$) with high efficiencies over a wide load range. In addition, the input boost inductors operate in a discontinuous mode to improve the input power factor. Moreover, all the switching devices operate with ZVS, and the converter's THD is small especially at full load. The feasibility of the proposed converter is verified with experimental results of a 1.5kW prototype.