An improved DC-DC converter with high voltage gain based on fully tapped quadratic boost converter for grid connected solar PV micro-inverter

Author(s):  
Lakhdar Bentouati ◽  
Ali Cheknane ◽  
Boumediène Benyoucef ◽  
Oscar Barambones

The need to increase the voltage level produced by PV systems becomes an urgent task to be compatible with the requirements of the AC load, but we meet problems in the operation of the step-up converter at a high duty cycle which is not preferred due to the reduction in voltage gain, and also a higher number of turns ratio in the windings inductance coupled adds to the overall losses of the converter. This article proposes an improved DC-DC converter with a lower duty cycle by integrating three tapped-inductors in new topology, which combined quadratic boost converter and tapped-inductor boost converter. The proposed converter achieves a high voltage gain with a lower duty ratio (Gmax = 14.32) and a maximum efficiency of 98.68% is improved compared to the voltage gain and efficiency results of these converters in several recently published references. The analyses are done theoretically and supported with simulation results. A prototype of the proposed converter has been built to experimentally validate the obtained results.

2021 ◽  
Author(s):  
HENRIQUE JAHNKE HOCH ◽  
TIAGO MIGUEL KLEIN FAISTEL ◽  
ADEMIR TOEBE ◽  
ANTóNIO MANUEL SANTOS SPENCER ANDRADE

High step-up DC-DC converters are necessary in photovoltaic energy generation, due the low voltage of the panels source. This article propose the Doubler Output Coupled Inductor converter. This converter is based in boost converter and utilize switched capacitors and a coupled inductor to maximize the static voltage gain. The converter achieve a high voltage gain with low turns ratio in the coupled inductor and an acceptable duty cycle. Can highlight the converter utilize low number of components and have low voltage and current stresses in semiconductors. To validate and evaluate the operation of the converter a 200W prototype is simulated.


Author(s):  
Christophe Raoul Fotso Mbobda ◽  
Alain Moise Dikandé

To provide a high votage conversion ratio, conventional non-isolated DC-DC boost topologies, which have reduced voltage boost capability, have to operate with extremely high duty cycle ratio, higher than 0.9. This paper proposes a DC-DC converter which is mainly based on the narrow range of duty cycle ratio to achieve extra high voltage conversion gain at relatively reduced voltage stress on semiconductors. In addition, it does include any magnetic coupling structure. The structure of the proposed converter combines the new hybrid SEPIC converter and voltage multiplier cells. From the steady-state analysis, this converter has wide conversion ratio and cubic dependence with respect to the duty ratio and then, can increase the output voltage several times more than the conventional and quadratic converters at the same duty cycle ratio. However, the proposed dual-switch cubic SEPIC converter must withstand higher voltage stress on output switches. To overcome this drawback, an extension of the proposed converter is also introduced and discussed. The superiority of the proposed converter is mainly based on its cubic dependence on the duty cycle ratio that allows it to achieve extra high voltage gain at reduced voltage stress on semiconductors. Simulation results are shown and they corroborate the feasibility, practicality and validity of the concepts of the proposed converter.


This paper introduces a modern, transformerless buck-boost dc-dc converter. In this topology, one active switch is used. The proposed buck-boost converter voltage gain is higher compared to the conventional buck-boost converter. With a moderate duty cycle, high voltage gain can be reached. The switch's voltage stress is minimal. As a consequence, the power switch's conduction loss is relatively low to improve efficiency. The converter is simple, hence it will be easy to control the proposed converter.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2312 ◽  
Author(s):  
M. Karthikeyan ◽  
R. Elavarasu ◽  
P. Ramesh ◽  
C. Bharatiraja ◽  
P. Sanjeevikumar ◽  
...  

In the current era, the desire for high boost DC-to-DC converter development has increased. Notably, there has been voltage gain improvement without adding extra power switches, and a large number of passive components have advanced. Magnetically coupled isolated converters are suggested for the higher voltage gain. These converters use large size inductors, and thus the non-isolated traditional boost, Cuk and Sepic converters are modified to increase their gain by adding an extra switch, inductors and capacitors. These converters increase circuit complexity and become bulky. In this paper, we present a hybrid high voltage gain non-isolated single switch converter for photovoltaic applications. The proposed converter connects the standard conventional Cuk and boost converter in parallel for providing continuous current mode operation with the help of a single power switch, which gives less voltage stress on controlled switch and diodes. The proposed hybrid topology uses a single switch with a lower component-count and provides a higher voltage gain than non-isolated traditional converters. The converter circuit mode of operation, operating performance, mathematical derivations and steady-state exploration and circuit parameters design procedures are deliberated in detail. The proposed hybrid converter circuit components, voltage gain and performance, were compared with other topologies in the literature. The MATLAB/Simulink simulation study and microcontroller-based experimental laboratory prototype of 150 W were implemented. The simulation study and experimentation results were confirmed to be a satisfactory agreement with the theoretical analysis. This topology produced non-inverting output in continuous input current mode using a single switch with high voltage gain (≈5.116 gain) with a maximum efficiency of 92.2% under full load.


Author(s):  
C. Kumar ◽  
T. Dharma Raj

The solar photovoltaic (PV) source is preferred to be functioned at low voltages. The practical systems such as grid-tied systems require a high output voltage causing a reduction in conversion efficiency. To handle this problem, this paper presents a new nonisolated boost DC–DC converter with a single switch suitable for solar PV applications. This converter comprises dual voltage multiplier (VM) cells, leakage energy recovery scheme, and coupled inductor (CI) techniques to get the desired output voltage from the converter. The double-clamp capacitors are connected to the primary side of the CI. The clamp capacitors can share the current through CI, and it ensures that the leakage inductance energy of CI can be recovered, leading to an expansion in the converter voltage gain and conversion efficiency. In addition, the clamp circuit clamps the voltage stress of the MOSFET switch, and the clamp capacitors will discharge at a specific time to increase the converter gain. A high duty cycle is not necessary for getting a high voltage gain, which avoids the diode reverse recovery issues. The converter can be operated in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). A 500-W experimental prototype is developed for experimental validation, and the supporting simulation results are presented. The maximum efficiency of the converter is 93.94%, and, at full load, the efficiency is 92.55%.


Author(s):  
Luiz H. S. C. Barreto ◽  
Paulo P. Praca ◽  
Gustavo A. L. Henn ◽  
Raphael A. Camara ◽  
N. A. L. S. Ranoyca ◽  
...  

2014 ◽  
Vol 61 (12) ◽  
pp. 6739-6746 ◽  
Author(s):  
George Cajazeiras Silveira ◽  
Fernando Lessa Tofoli ◽  
Luiz Daniel Santos Bezerra ◽  
Rene Pastor Torrico-Bascope

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