Search

A synthesis methodology for developing a set of very high step-up dc–dc converters is presented and discussed in this paper. The proposed method makes use of a boost converter as basic topology in which three step-up techniques are combined and incorporated. The studied techniques are the switched capacitors voltage multipliers (VM), the diode VMs, and the coupled-inductors. With the proposed methodology, many well-known converters are identified and two novel converters are proposed. In addition to a detailed analysis of the synthesis of each topology, a comparative analysis among of some important converters is presented. This comparison involves aspects such as voltage gain, voltage stress, component stress factor, component count, and relative cost. By means of these comparisons, the main characteristics and constraints of the analyzed converters are identified. Results from 250 W prototypes, designed according to photovoltaic ac-module specifications, are obtained experimentally to validate the theoretical analyses and point out advantages and limitations of each converter. The results demonstrate that the combination of the three studied techniques provides the best trend off on the comparative analysis carried out in this work. [ABSTRACT FROM PUBLISHER]

This paper presents a comparative evaluation of eight high-voltage step-up converters based on different associations of boost and zeta standard dc–dc pulse width modulation (PWM) cells. These eight converters present different characteristics such as cascaded and stacked PWM cell associations, as well as isolated winding coupled inductors, tapped winding coupled inductors, and noncoupled inductors. In order to explore the advantages and address the limitations of each topology, several comparative evaluations concerning static voltage gain, power losses, current and voltage stresses, component stress factors, power density, relative cost, and efficiency were carried out. From the theoretical analysis and experimental results, the association named stacked boost–zeta with autotransformer yielded the highest efficiency and power density and resulted in the most attractive converter for the case study. [ABSTRACT FROM PUBLISHER]