Hybrid bridgeless DCM SEPIC rectifier integrated with a modified switched capacitor cell

Abstract

In this paper is proposed a novel single-phase PWM bridgeless rectifier, based on SEPIC converter topology, integrated with a modified switched capacitor cell. The structure has the absence of the diode bridge at the input port reducing the number of components and conduction losses. Besides, it has the presence of a switched capacitor cell, providing double gain at the output voltage. A comparison with the conventional SEPIC shows that the proposed converter has lower voltage stress on the semiconductors when both converters are designed for the same output voltage, and the same voltage stress across the semiconductors when the output voltage of the proposed converter is twice bigger than the conventional SEPIC. Therefore, the proposed structure can be applied in DCM SEPIC rectifiers improving the converter static gain, making it suitable for higher voltage applications. The paper also proposes a modified switched capacitor cell, which does not change the storage capacitor operation mode of the SEPIC rectifier. To validate the theoretical analyses a prototype of 500 W was built considering an input and an output voltage of 220 V and 400 V, respectively, and a switching frequency of 50 kHz.