A high step‐up half‐bridge DC/DC converter with a special coupled inductor for input current ripple cancelation and extended voltage doubler circuit for power conditioning of fuel cell systems

Summary Renewable sources of low voltage are an important resource in power generation systems. Many provide high output current at low voltage, as the photovoltaic modules and fuel cells systems, therefore, become more popular considering the safety requirements. In this paper, a novel current‐fed three‐phase dc‐dc converter with high‐frequency isolation transformer is proposed. This one has the main features as high dc voltage gain, reduced switches count, minimize the volume of the output/input filters, the frequency ripple of the input current and output voltage are three times higher than the switching frequency, best losses distribution and reduced stresses in the circuit. Moreover, it operates with wide‐range duty cycle, the soft‐start can be used, which allows the input current and the output voltage to be started gradually. Operating with a duty cycle of 1/3 and 2/3, the input current ripple is canceled. The proposed converter is studied qualitatively and quantitatively, being presented the operation principle in continuous and discontinuous conduction mode, dc voltage gain in each operation mode, and the voltage and current stresses for the power components sizing. To validate the operation of the proposed converter, the laboratory design example and experimental results are presented to demonstrate the performance and validate the claims of the converter for wide load variation. Experimental results are presented for a 4‐kW prototype, operating in R2 region for continuous conduction mode. Additionally, experimental results in R1 and R3 regions are obtained.

Section: Figurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Three‐phase step‐up/step‐down isolated dc‐dc converter with wide‐range duty cycle for low dc renewable energy sources applications

Mayer

Kattel

Oliveira

2018

“…To obtain an acceptable input current ripple, several topologies have been extensively studied, which can be classified as magnetic and nonmagnetic. The former are designed taking into account the transformation ratio of the coupled inductors or the transformer, [9][10][11][12] increasing the losses and complexity, though. Several approaches have been successfully presented.…”

Section: Introductionmentioning

confidence: 99%

Analysis and implementation of a step–up power converter with input current ripple cancelation

García–Vite

Rivera-Espinosa

Alejandre-Lopez

et al. 2018

Summary This paper proposes a power electronics converter capable of canceling the input current ripple at preselected duty cycle. The proposed converter is an extended topology of a buck–boost converter aided by a boost‐type converter that improves the quality of the current drawn from the direct current source. The voltage gain of the proposed converter is increased as well, with a minimum of extra component added to the original buck–boost power converter. These features make the proposed converter ideal for low voltage generation sources, such as photovoltaic panel and fuel cell applications. Along this paper, the state space mathematical model is developed to provide the key design guidelines. The theoretical analysis is validated through computer simulation and hardware prototyping.

“…Direct current to direct current converters can be classified into isolated and nonisolated types . Each type can also be further categorized into coupled inductor or noncoupled inductor‐based topologies. Usually, nonisolated noncoupled inductor‐based topologies have much lower voltage gains in comparison with isolated coupled inductor ones.…”

Section: Introductionmentioning

confidence: 99%

A high‐voltage gain nonisolated noncoupled inductor based multi‐input DC‐DC topology with reduced number of components for renewable energy systems

Varesi

Hosseini

Sabahi

et al. 2017

Summary This paper proposes a modular nonisolated noncoupled inductor‐based high‐voltage gain multi‐input DC‐DC converter. Despite the high‐voltage gain of the proposed topology, the average of normalized voltage stress (NVS) on its switches/diodes is low. This property leads to less loss and cost of switches/diodes. Using the same number of components, the proposed topology produces higher voltage gains, in comparison with recently presented high step‐up topologies. Also, the proposed topology utilizes less number of components (capacitors, inductors, diodes, and switches) for producing a desired voltage gain, which can reduce the size, mass, cost, complexity, and losses and improve the efficiency of converter. Continuous current of input sources is another main advantage of the proposed topology. All the abovementioned characteristics have made the proposed topology very suitable for renewable energy systems (or even hybrid/electric vehicles). Design considerations of the proposed topology have also been presented. For better evaluation, the proposed topology has been compared with some of recently presented high step‐up structures, from viewpoints of producible voltage gain, number of components, and normalized voltage stress (NVS) on switches/diodes. Finally, the prototype of 2‐input version has been experimentally implemented. Obtained experimental results confirm appropriate performance of the proposed topology.