scholarly journals A High-Efficiency, Low-Cost Solution for On-Board Power Converters

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
V. Boscaino ◽  
G. Capponi
Keyword(s):  
Power Efficiency ◽  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Input Voltage ◽  
High Current ◽  
Forward Converter ◽  
System Cost ◽  
Zero Voltage Switching ◽  
Reset Voltage

Wide-input, low-voltage, and high-current applications are addressed. A single-ended isolated topology which improves the power efficiency, reduces both switching and conduction losses, and heavily lowers the system cost is presented. During each switching cycle, the transformer core reset is provided. The traditional tradeoff between the maximum allowable duty-cycle and the reset voltage is avoided and the off-voltage of active switches is clamped to the input voltage. Therefore, the system cost is heavily reduced and the converter is well suited for wide-input applications. Zero-voltage switching is achieved for active switches, and the power efficiency is greatly improved. In the output mesh, an inductor is included making the converter suitable for high-current, low-voltage applications. Since the active clamp forward converter is the closest competitor of the proposed converter, a comparison is provided as well. In this paper, the steady-state and small-signal analysis of the proposed converter is presented. Design examples are provided for further applications. Simulation and experimental results are shown to validate the great advantages brought by the proposed topology.

scholarly journals A Comparative Analysis of Half-Bridge LLC Resonant Converters Using Si and SiC MOSFETs

2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Hasaan Farooq ◽  
Hassan Abdullah Khalid ◽  
Waleed Ali ◽  
Ismail Shahid
Keyword(s):  
Silicon Carbide ◽  
Renewable Energy ◽  
High Frequency ◽  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Input Voltage ◽  
Resonant Converters ◽  
Wide Range

With the expansion of renewable energy sources worldwide, the need for developing more economical and more efficient converters that can operate on a high frequency with minimal switching and conduction losses has been increased. In power electronic converters, achieving high efficiency is one of the most challenging targets to achieve. The utilization of wideband switches can achieve this goal but add additional cost to the system. LLC resonant converters are widely used in different applications of renewable energy systems, i.e., PV, wind, hydro and geothermal, etc. This type of converter has more benefits than the other converters such as high electrical isolation, high power density, low EMI, and high efficiency. In this paper, a comparison between silicon carbide (SiC) MOSFET and silicon (Si) MOSFET switches was made, by considering a 3KW half-bridge LLC converter with a wide range of input voltage. The switching losses and conduction losses were analyzed through mathematical calculations, and their authenticity was validated with the help of software simulations in PSIM. The results show that silicon carbide (SiC) MOSFETs can work more efficiently, as compared with silicon (Si) MOSFETs in high-frequency power applications. However, in low-voltage and low-power applications, Si MOSFETs are still preferable due to their low-cost advantage.

scholarly journals Resonant Hybrid Flyback, a New Topology for High Density Power Adaptors

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 363 ◽  
Author(s):  
Alfredo Medina-Garcia ◽  
Manfred Schlenk ◽  
Diego Morales ◽  
Noel Rodriguez
Keyword(s):  
Power Density ◽  
Pulse Width Modulation ◽  
High Efficiency ◽  
Full Range ◽  
Input Voltage ◽  
Zero Voltage Switching ◽  
Zero Current Switching ◽  
Zero Current ◽  
Class Power ◽  
World Class

In this article, an innovative power adaptor based on the asymmetrical pulse width modulation (PWM) flyback topology will be presented. Its benefits compared to other state-of-the-art topologies, such as the active clamp flyback, are analyzed in detail. It will also describe the control methods to achieve high efficiency and power density using zero-voltage switching (ZVS) and zero-current switching (ZCS) techniques over the full range of the input voltage and the output load, providing comprehensive guidelines for the practical design. Finally, we demonstrate the convenience of the proposed design methods with a 65 W adaptor prototype achieving a peak efficiency of close to 95% and a minimum efficiency of 93.4% at full load over the range of the input voltage, as well as a world-class power density of 22 W/inch3 cased.

scholarly journals Hybrid LLC Converter with Wide Range of Zero-Voltage Switching and Wide Input Voltage Operation

2020 ◽  
Vol 10 (22) ◽  
pp. 8250
Author(s):  
Bor-Ren Lin ◽  
Kun-Yi Chen
Keyword(s):  
Low Voltage ◽  
Input Voltage ◽  
Resonant Circuit ◽  
Zero Voltage Switching ◽  
Photovoltaic Energy Conversion ◽  
Wide Range ◽  
Input Side ◽  
Input Region ◽  
Output Side ◽  
Zero Voltage

A new hybrid inductor-inductor-capacitor (LLC) converter is investigated to have wide voltage input operation capability and zero-voltage turn-on characteristics. The presented circuit topology can be applied for consumer power units without power factor correction or with long hold-up time requirement, photovoltaic energy conversion and renewable energy power transfer. To overcome the weakness of narrow voltage gain of resonant converter, the hybrid LLC converter with different turns ratio of transformer is presented and the experimental investigation is provided to achieve wide voltage input capability (400 V–50 V). On the input-side, the converter can operate as full bridge resonant circuit or half bridge resonant circuit with input split capacitors for high or low voltage input region. On the output-side, the less or more winding turns is selected to overcome wide voltage input operation. According to the circuit structures and transformer turns ratio, the single stage LLC converter with wide voltage input operation capability (400 V–50 V) is accomplished. The laboratory prototype has been developed and the experimental waveforms are measured and demonstrated to investigate the effectiveness of the presented hybrid LLC converter.

scholarly journals Full-Bridge Active-Clamp Forward-Flyback Converter with an Integrated Transformer for High-Performance and Low Cost Low-Voltage DC Converter of Vehicle Applications

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 863 ◽  
Author(s):  
Jaeil Baek ◽  
Han-Shin Youn
Keyword(s):  
High Power ◽  
High Performance ◽  
Low Voltage ◽  
Low Cost ◽  
Primary Root ◽  
Input Voltage ◽  
Oxide Semiconductor ◽  
Duty Ratio ◽  
Voltage Range ◽  
Active Clamp

This paper presents a full-bridge active-clamp forward-flyback (FBACFF) converter with an integrated transformer sharing a single primary winding. Compared to the conventional active-clamp-forward (ACF) converter, the proposed converter has low voltage stress on the primary switches due to its full-bridge active-clamp structure, which can leverage high performance Silicon- metal–oxide–semiconductor field-effect transistor (Si-MOSFET) of low voltage rating and low channel resistance. Integrating forward and flyback operations allows the proposed converter to have much lower primary root mean square (RMS) current than the conventional phase-shifted-full-bridge (PSFB) converter, while covering wide input/output voltage range with duty ratio over 0.5. The proposed integrated transformer reduces the transformer conduction loss and simplify the secondary structure of the proposed converter. As a result, the proposed converter has several advantages: (1) high heavy load efficiency, (2) wide input voltage range operation, (3) high power density with the integrated transformer, and (4) low cost. The proposed converter is a very promising candidate for applications with wide input voltage range and high power, such as the low-voltage DC (LDC) converter for eco-friendly vehicles.

scholarly journals Review on Photovoltaic Based Grid-Tied System using H6 Transformer Less Full-Bridge Inverters

2021 ◽  
pp. 85-87
Author(s):  
Suraj Barade ◽  
Sneha Tibude
Keyword(s):  
Power Efficiency ◽  
High Efficiency ◽  
Low Cost ◽  
Power Device ◽  
Power Losses ◽  
Safety Requirement ◽  
Leakage Currents ◽  
Similar Performance ◽  
Low Leakage ◽  
Pv Generation

Transformer less inverters are widely used in grid-tied photovoltaic (PV) generation systems, due to the benefits of achieving high efficiency and low cost. Various transformer less inverter topologies have been proposed to meet the safety requirement of leakage currents, such as specified in the VDE-4105 standard. In this thesis, a family of H6 transformer less inverter topologies with low leakage currents is proposed, and the intrinsic relationship between H5 topology, highly efficient and reliable inverter concept (HERIC) topology, and the proposed H6 topology has been discussed as well. One of the proposed H6 inverter topologies is taken as an example for detail analysis with operation modes and modulation strategy. The power losses and power device costs are compared among the H5, the HERIC, and the proposed H6 topologies. A universal prototype is built for these three topologies mentioned for evaluating their performances in terms of power efficiency and leakage currents characteristics. Experimental results show that the proposed H6 topology and the HERIC achieve similar performance in leakage currents, which is slightly worse than that of the H5 topology, but it features higher efficiency than that of H5 topology.

scholarly journals Soft-Switching High Gain Step-Up DC/DC Converter without Auxiliary Switches

2019 ◽  
Vol 8 (12S) ◽  
pp. 633-636
Keyword(s):  
Theoretical Analysis ◽  
Power Flow ◽  
High Efficiency ◽  
Input Voltage ◽  
High Gain ◽  
Soft Switching ◽  
Zero Voltage Switching ◽  
Auxiliary Cell ◽  
Zero Voltage ◽  
Voltage Switching

This manuscript presents a novel high gain, high efficiency Soft-switching high step-up DC/DC converter for battery-operated vehicles. The high step-up converter can transfer the power flow from the small voltage to high voltage. The conventional two input inductor hard switched non-isolated DC-DC converter improved with an additional auxiliary cell to attain the Zero voltage switching, due to obtaining the softswitching the efficiency may improve and reduces the stress across the main switches. The isolated converters are used as a transformer to attain high gain, whereas in the proposed converter obtains the high gain without a transformer and contains the high efficiency in the step-up mode of operation. The main aim of the converter is to attain the Zero voltage switching without using any additional auxiliary switches. In this paper, the input voltage applied as 30V, and the obtained output voltage is fifteen times to the applied voltage, which is 450V and the output power 850W. This paper mainly presents the theoretical analysis of converter operation and the evaluation of the simulation results validated with the theoretical analysis.

scholarly journals Cell Lysis Based on an Oscillating Microbubble Array

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 288
Author(s):  
Xiufang Liu ◽  
Jinyuan Li ◽  
Liangyu Zhang ◽  
Xiaowei Huang ◽  
Umar Farooq ◽  
...  
Keyword(s):  
Cell Biology ◽  
High Speed ◽  
High Efficiency ◽  
Low Cost ◽  
Cell Lysis ◽  
Input Voltage ◽  
Disease Diagnosis ◽  
Cancer Diagnostics ◽  
Significant Difference ◽  
The Individual

Cell lysis is a process of breaking cell membranes to release intracellular substances such as DNA, RNA, protein, or organelles from a cell. The detection of DNA, RNA, or protein from the lysed cells is of importance for cancer diagnostics and drug screening. In this study, we develop a microbubble array that enables the realization of multiple cell lysis induced by the shear stress resulting from the individual oscillating microbubbles. The oscillating microbubbles in the channel have similar vibration amplitudes, and the intracellular substances can be released from the individual cells efficiently. Moreover, the efficiency of cell lysis increases with increments of input voltage and sonication time. By means of DNA agarose-gel electrophoresis, a sufficient extraction amount of DNA released from the lysed cells can be detected, and there is no significant difference in lysis efficiency when compared to cell lysis achieved using commercial kits. With the advantages of the simple manufacturing process, low cost, high efficiency, and high speed, this device can serve as an efficient and versatile tool for the single-cell sequencing of cell biology research, disease diagnosis, and stem cell therapy.

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