Single-phase/-switch voltage-doubler DCM SEPIC rectifier with high power factor and reduced voltage stress on the semiconductors

Abstract

This paper proposes a single-phase SEPIC rectifier that works in discontinuous conduction mode (DCM). The proposed rectifier employs a three-stage switch and a voltage-doubler structure. Hence, it works as two half-wave rectifiers with the output voltages series-connected and thus it provides a higher voltage gain. The paper presents the theoretical analysis of the proposed structure and it also discusses a comparison between the proposed converter and the classic SEPIC rectifier, which shows that the proposed converter might either provide reduced voltage stress on the semiconductors to the same output voltage level, or it might supply double the gain in the output voltage with the same voltage stress. In both cases, the novel rectifier maintains the high power factor with no current control from the classical DCM SEPIC rectifier. The study was verified by experimental results obtained with a prototype of 1000 W, 220 V at input voltage, 400 V at output voltage and 50 kHz at switching frequency. Testes at rated power provided a current THD equal to 3.2%, a power factor of 0.9992 and an efficiency of 94.34%.