Single‐phase hybrid discontinuous conduction mode SEPIC rectifiers integrated with ladder‐type switched‐capacitor cells

Abstract

In this study, a set of new single-phase pulse-width modulation (PWM) Single-ended primary-inductor converter (SEPIC) rectifiers are proposed, which integrates conventional SEPIC rectifier, three-state switch (TSS) and switched-capacitor (SC) concepts. A conventional ladder-type SC cell is modified so that it can be integrated with the SEPIC rectifier operating in discontinuous conduction mode. The set of new single-phase PWM SEPIC rectifiers are able to provide: (i) lower-voltage stress on the semiconductors; (ii) higher-output voltage; and (iii) a split-capacitor output voltage. The structure employs a TSS and three different implementations are proposed. Two of them are bridgeless versions, which can provide higher efficiencies. Hence, the proposed structures can support using the SEPIC rectifiers as step-up in many applications and thus it can broaden its field of use. The topologies and their topological states, a theoretical steady-state analysis, a theoretical analysis of the ladder-type SC cell integrated with the SEPIC rectifier, a dynamic model for the control and a design example are discussed herein. Furthermore, a 500 W prototype with a 220 V input voltage, two 200 V split-output voltages, 400 V total output voltage and 50 kHz switching frequency was designed to corroborate the theoretical study.

A three‐level isolated dc‐dc SEPIC converter with parallel‐connected output

“…Converters derived from the single‐ended primary‐inductance converter (SEPIC) structure are widely used in renewable energies applications 3–7 . Other examples where the SEPIC is also used include power factor correction (PFC), 8–11 LED lighting drivers, 12–16 battery chargers 17–19 and DC microgrids 20 …”

“…Converters derived from the single-ended primary-inductance converter (SEPIC) structure are widely used in renewable energies applications. [3][4][5][6][7] Other examples where the SEPIC is also used include power factor correction (PFC), [8][9][10][11] LED lighting drivers, [12][13][14][15][16] battery chargers [17][18][19] and DC microgrids. 20 The SEPIC-type topologies present attractive characteristics when compared with other structures, including (i) continuous input current with low ripple; (ii) operation as a step-down/step-up voltage regulator without reversing the polarity of the output voltage, unlike the buck-boost, and Cùk converters; (iii) operating with a wide input voltage range due to step-up/step-down static gain; (iv) output voltage source characteristic, attractive for some applications;…”

A new transformer‐less step‐up DC–DC converter with high voltage gain and reduced voltage stress on switched‐capacitors and power switches for renewable energy source applications

“…Besides, this system is a suitable candidate for high‐temperature operations. In [25], a set of single‐phase pulse‐width modulation Sepic converters are developed based on conventional Sepic rectifier, three‐state switch, and SC concepts. This set can provide benefits such as lower voltage stress on switches, higher output voltage, and a split‐capacitor output voltage.…”