scholarly journals The Improvement Switching Technique for High Step-Up DC-DC Boost Converter

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 981
Author(s):  
Viet-Anh Truong ◽  
Xuan-Truong Luong ◽  
Phan-Thanh Nguyen ◽  
Thanh-Hai Quach
Keyword(s):  
Energy Conversion ◽  
Duty Cycle ◽  
Mathematical Analysis ◽  
Energy Conversion Efficiency ◽  
Control Area ◽  
Maximum Efficiency ◽  
Activity Levels ◽  
Constant Voltage ◽  
Voltage Multiplier ◽  
Coupled Inductors

This paper proposes the non-isolated DC-DC converter with high boost ratios and efficiency. We suggest boosting methods including voltage multiplier cells or coupled inductors. However, both techniques have a limited constant voltage multiplier coefficient according to the fixed configuration. Therefore, in the proposed method, we change the multiplier factor (as the number of activity levels) and combine it with the turn of the appropriate duty cycle; these factors are considered at the same time in order to increase the energy conversion efficiency and expand the control area of the duty cycle. A mathematical analysis of the losses of the components in operation modes shows that the boost ratio and efficiency are functions of the number of activity levels and duty cycle. Therefore, this paper proposes an algorithm for tracking the activity levels and duty cycle in order to obtain the maximum efficiency. The simulations produced with the Powersim-PSIM software, and the experiments with load capacities of 250 W, 500 W and 1000 W, boosting the ratio by more than ten times, were conducted in order to clarify the capabilities of the proposed configuration.

scholarly journals Dielectric elastomer generator with diaphragm configuration

2018 ◽  
Vol 192 ◽  
pp. 01032
Author(s):  
Zhen-Qiang Song ◽  
Sriyuttakrai Sathin ◽  
Wei Li ◽  
Kazuhiro Ohyama ◽  
ShiJie Zhu
Keyword(s):  
Energy Density ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Energy Conversion Efficiency ◽  
Dielectric Elastomer ◽  
Maximum Energy ◽  
Constant Voltage ◽  
Low Viscosity ◽  
65 J ◽  
Low Efficiency

The dielectric elastomer generator (VHB 4905, 3M) with diaphragm configuration was investigated with the constant-voltage harvesting scheme in order to investigate its energy harvesting ability. The maximum energy density and energy conversion efficiency is measured to be 65 J/kg and 5.7%, respectively. The relatively low efficiency indicates that higher energy conversion efficiency is impeded by the viscosity of the acrylic elastomer, suggesting that higher conversion efficiency with new low-viscosity elastomer should be available.

scholarly journals High-Gain High-Efficiency DC–DC Converter with Single-Core Parallel Operation Switched Inductors and Rectifier Voltage Multiplier Cell

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4634
Author(s):  
Eduardo Augusto Oliveira Barbosa ◽  
Márcio Rodrigo Santos de Carvalho ◽  
Leonardo Rodrigues Limongi ◽  
Marcelo Cabral Cavalcanti ◽  
Eduardo José Barbosa ◽  
...  
Keyword(s):  
High Voltage ◽  
Duty Cycle ◽  
High Efficiency ◽  
High Gain ◽  
Voltage Gain ◽  
Parallel Operation ◽  
Voltage Multiplier ◽  
Coupled Inductors ◽  
High Voltage Gain

This paper proposes a high step-up high-efficiency converter, comprised of an active switched coupled-inductor cell. The secondary windings are integrated into a rectifier voltage multiplier cell in a boost-flyback configuration, allowing the operation with high voltage gain with low switches duty cycle and low turn-ratios on the coupled-inductors. Both coupled-inductors are integrated into a single core due to the parallel operation of the switches. The leakage inductances of the coupled-inductors are used to mitigate the reverse recovery currents of the diodes, while regenerative clamp circuits are used to protect the switches from the voltage spikes caused by the leakage inductances. The operation of the converter is analyzed both quantitatively and qualitatively, and the achieved results are validated through experimentation of a 400 W prototype. A 97.1% CEC efficiency is also reported.

scholarly journals Efficient Voltage Regulation with Modified Hybrid SEPIC DC-DC-Converter

2018 ◽  
Vol 160 ◽  
pp. 02004
Author(s):  
Md. Ali Azam Khan ◽  
Mohammad Ali Choudhury
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Energy Conversion Efficiency ◽  
Voltage Regulation ◽  
Voltage Gain ◽  
High Attenuation ◽  
Voltage Multiplier ◽  
Duty Cycles ◽  
Switch Mode ◽  
Very High

Switch mode dc-dc converters are attractive for their small size, ease of control and efficient power conversion. Output voltage is regulated by duty cycle control of semiconductor switch of switch mode dc-dc converters. The voltage gain and efficiency of practical switching regulators deviate from ideal values at extreme duty cycles. Also, desired gain /attenuation is not achievable at high/low duty cycles. In applications where high gain or high attenuation of voltage is desired with acceptable energy conversion efficiency, hybrid dc-dc switching converters are used. Hybrid dc-dc converters are combination of voltage multiplier/division circuit with appropriate SMPS circuits. By incorporating voltage multiplier/division cell with conventional SEPIC converters, desired voltage gain (either very low or very high) may be achieved at acceptable energy conversion efficiency. In the present work with an aim to attain very high voltage gain by conventional SEPIC topologies, a new voltage multiplier cell consisting of multiple inductors and diodes is proposed.

Current progress and performance improvement of Pt/C catalysts for fuel cells

2020 ◽  
Vol 8 (46) ◽  
pp. 24284-24306
Author(s):  
Xuefeng Ren ◽  
Yiran Wang ◽  
Anmin Liu ◽  
Zhihong Zhang ◽  
Qianyuan Lv ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Energy Conversion ◽  
Performance Improvement ◽  
Electric Energy ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Carnot Cycle ◽  
High Energy Conversion Efficiency ◽  
And Performance

Fuel cell is an electrochemical device, which can directly convert the chemical energy of fuel into electric energy, without heat process, not limited by Carnot cycle, high energy conversion efficiency, no noise and pollution.

First-principles study on the electronic and optical properties of the orthorhombic CsPbBr3 and CsPbI3 with Cmcm space group

2021 ◽  
Author(s):  
Xianhao Zhao ◽  
Tianyu Tang ◽  
Quan Xie ◽  
like gao ◽  
Limin Lu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
First Principles ◽  
Energy Conversion Efficiency ◽  
Space Group ◽  
Absorbing Materials ◽  
Halide Perovskites ◽  
Lead Halide

The cesium lead halide perovskites are regarded as effective candidates for light-absorbing materials in solar cells, which have shown excellent performances in experiments such as promising energy conversion efficiency. In...

scholarly journals Optical Parametric Oscillation with Ultra-low Power Threshold in a Dimer of Active-Passive Cavities

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 566
Author(s):  
Bo Lu ◽  
Chen-Rui Fan ◽  
Jun-Yang Song ◽  
Chuan Wang
Keyword(s):  
Pump Power ◽  
Energy Conversion ◽  
Energy Conversion Efficiency ◽  
Parametric Oscillation ◽  
Optical Parametric Oscillation ◽  
Optical Parametric ◽  
Non Linear ◽  
Oscillation Process ◽  
Power Threshold ◽  
Low Threshold

Optical parametric oscillation can convert the input laser into a couple of coherent optical output with signal and idler frequencies. It is an important method for the realization of the broadband middle infrared tunable lasers. The optical parametric oscillation process depends on the ultra-fast non-linear response of matter to light with a certain pump power. Therefore, reducing the pump threshold of the optical parametric oscillation process and improving the energy conversion efficiency are of great significance to the study of non-linear optics. In this paper, we construct a dimer system that couples a passive non-linear resonator to an active resonator. Based on the dimer system, an ultra-low threshold optical parametric oscillation generation method is proposed. By coupling the gain pump mode, the non-linear effect is effectively enhanced, the pump power threshold is reduced to half of when there is no gain, and the energy conversion efficiency is increased. We believe this research provides a feasible method for a low-threshold tunable and easy-to-integrate optical parametric oscillation laser source.

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