Quasi‐active power factor correction on flyback‐based dc/dc converter

Abstract

This paper presents a novel input current shaper based on a quasi-active power factor correction (PFC) scheme. In this method, high power factor and low harmonic content are achieved by providing an auxiliary PFC circuit with a driving voltage which is derived from a third winding of the transformer of a cascaded dc/ dc flyback converter. It eliminates the use of active switch and control circuit for PFC. The auxiliary winding provides a controlled voltage-boost function for bulk capacitor without inducing a dead angle in the line current. Since the dc/dc converter operates at high switching frequency, the driving voltage is also of high switching frequency, which results in reducing the size of the magnetic components. Operating principles, analysis and experimental results of the proposed method are presented.

Step‐up/step‐down DC‐DC converter with near zero input/output current ripples

“…(d) The critical conduction parameter K e-crit : the value of K e-crit can be evaluated from (12), and it is given by…”

“…Designing high-performance power converter with low cost, small size, and high efficiency makes the electromagnetic interference (EMI) design a more challenging task [1]. The Zeta and the Flyback converters [4][5][6][7][8][9][10][11][12][13] require an additional input/output L-C filter to reduce the switching ripple and noise level at both terminals. For these applications, the Cuk converter seems to be a potential candidate within the basic converter topologies [3].…”

A DSP‐based implementation of fuzzy logic and predictive current control for a Sheppard–Taylor power factor correction converter

“…Most active PFC circuits as well as SMPS involve two stages: a front‐end bridge rectifier and a DC/DC converter to achieve the desired output voltage. Several conventional DC/DC topologies have been introduced in the literature to act as PFC pre‐regulators, such as Cuk, 7,8 Boost, 2,6,9,10 Luo, 11 and Flyback 12 converters. However, most of the mentioned PFC converters are unable to control detuning phenomenon (Figure 1) that appears at low values of the alternating current (AC) network and leads to lose temporarily the control ability at the zero‐crossing of the AC network side 13 .…”