scholarly journals Dynamic duty-cycle limitation of the boost DC/DC converter allowing maximal output power operations

2016 ◽  
Author(s):  
Vratislav Michal
Keyword(s):  
Output Power ◽  
Duty Cycle ◽  
Power Operations ◽  
Maximal Output Power ◽  
Maximal Output

scholarly journals Monolithic high-average-power linearly polarized nanosecond pulsed fiber laser with near-diffraction-limited beam quality

2018 ◽  
Vol 6 ◽  
Author(s):  
Long Huang ◽  
Pengfei Ma ◽  
Daren Meng ◽  
Lei Li ◽  
Rumao Tao ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Output Power ◽  
Linear Polarization ◽  
Beam Quality ◽  
Average Power ◽  
Narrow Linewidth ◽  
High Average Power ◽  
Maximal Output Power ◽  
Maximal Output ◽  
Pulsed Fiber Laser

An all-fiberized high-average-power narrow linewidth ns pulsed laser with linear polarization is demonstrated. The laser system utilizes a typical master oscillator power amplifier (MOPA) configuration. The stimulated Brillouin scattering (SBS) is effectively suppressed due to the short fiber length and large mode area in the main amplifier, combined with the narrow pulse duration smaller than the phonon lifetime of SBS effect. A maximal output power of 466 W is obtained with a narrow linewidth of ${\sim}$203.6 MHz, and the corresponding slope efficiency is ${\sim}$80.3%. The pulse duration is condensed to be ${\sim}$4 ns after the amplification, corresponding to the peak power of 8.8 kW and the pulse energy of $46.6~\unicode[STIX]{x03BC}\text{J}$. Near-diffraction-limited beam quality with an $M^{2}$ factor of 1.32 is obtained at the output power of 442 W and the mode instability (MI) is observed at the maximal output power. To the best of our knowledge, this is the highest average output power of the all-fiberized narrow linewidth ns pulsed fiber laser with linear polarization and high beam quality, which is a promising source for the nonlinear frequency conversion, laser lidar, and so on.

scholarly journals CONTROL OVER THE PERFORMANCE OF MONOCRYSTALLINE SILICON SOLAR CELLS REFERRING TO THE POROUS SILICON LAYER / MONOKRISTALINIO SILICIO SAULĖS ELEMENTŲ CHARAKTERISTIKŲ VALDYMAS AKYTOJO SILICIO SLUOKSNIU

2012 ◽  
Vol 3 (6) ◽  
pp. 91-94
Author(s):  
Ramūnas Mitkevičius ◽  
Viktor Zagadskij ◽  
Eugenijus Šatkovskis
Keyword(s):  
Solar Cells ◽  
Porous Silicon ◽  
Output Power ◽  
Crystalline Silicon ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Silicon Solar Cells ◽  
Crystalline Silicon Solar Cells ◽  
Maximal Output Power ◽  
Maximal Output

The paper examines the parameters of crystalline silicon solar cells such as fill factor, maximal output power and series resistance forming a porous silicon layer. The obtained results show that introducing the layer into the structure of a solar cell results in a 19 percent enhancement of maximal output power and conversion efficiency. Santrauka Šiame darbe tiriamas akytojo silicio darinių poveikis saulės elementų elektrinėms charakteristikoms: nuosekliajai varžai, voltamperinių charakteristikų formai. Parodyta, kad pagaminus silicio saulės elemente akytojo silicio sluoksnį, galima veikti (valdyti) saulės elementų voltamperines charakteristikas ir elemento nuosekliąją elektrinę varžą. Nustatyta, kad tiriamajame bandinyje suformavus akytojo silicio sluoksnį, apkrovos voltamperinės charakteristikos užpildos rodiklis padidėjo 1,15 karto, o maksimali elemento kuriama ir apkrovos metu atiduodama elektros energijos galia – 1,19 karto. Tiek pat 1,19 karto padidėjo saulės elemento šviesos konversijos į elektros energiją efektyvumas.

An Integrated Numerical Model for a PEM Fuel Cell System

2013 ◽  
Vol 706-708 ◽  
pp. 1742-1745 ◽  
Author(s):  
Zhou Bo Ding ◽  
Li Ping He ◽  
Z. Dong ◽  
X. Gao
Keyword(s):  
Fuel Cell ◽  
Numerical Model ◽  
Output Power ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Fuel Cell System ◽  
Fuel Cell Stack ◽  
Operation Conditions ◽  
Maximal Output Power ◽  
Maximal Output

PEM Fuel Cell (PEMFC) system plays an important role in a future hydrogen economy. Numerical modeling is useful to evaluate and optimize PEM fuel cell system. Therefore, this paper developed an integrated numerical model for predicting the power output of PEMFC system and optimizing system operation parameters to achieve the maximal output power. The developed numerical model integrated the models of fuel cell stack itself and its auxiliary systems, which were quantitatively described and analyzed with calculation equations. Furthermore, the newly developed numerical model was applied to a PEMFC powered scooter to estimate the output power a PEMFC system and optimize the operation conditions parameters of its auxiliary systems based on optimization algorithm. This validates that the developed integrated numerical model is useful and reliable for predicting the net output power and achieving maximal net output power through optimizing the operating parameters of a PEMFC system.

Numerical investigation of an impact of a top gold metallization on output power of a p-up III-N-based blue-violet edge-emitting laser diode

2015 ◽  
Vol 23 (2) ◽  
Author(s):  
M. Kuc ◽  
R.P. Sarzała ◽  
S. Stańczyk ◽  
P. Perlin
Keyword(s):  
Output Power ◽  
Laser Diode ◽  
Thermal Performance ◽  
Optical Model ◽  
Ridge Waveguide ◽  
Waveguide Laser ◽  
Maximal Output Power ◽  
Maximal Output ◽  
Ridge Waveguide Laser ◽  
Gold Metallization

AbstractThe effect of modifications in epi-side (top) gold metallization on a thermal performance and on power roll-over of blue-vio- let III-N-based p-up edge-emitting ridge-waveguide laser diode (RW EEL) was explored in this paper. The calculations were carried out using a two-dimensional self-consistent electrical-thermal model combined with a simplified optical model tuned to a RW EEL fabricated in the Institute of High Pressure Physics (Unipress). Our results suggest that with proper modifica- tions in the III-N-based RW EEL, excluding modifications in its inner structure, it is possible to considerably improve the thermal performance and, thus, increase the maximal output power.

scholarly journals Investigation of Flyback Transformer Flux Leakage Reduction Ways

2017 ◽  
Vol 9 (3) ◽  
pp. 312-317
Author(s):  
Edvardas Bielskis ◽  
Martynas Šapurov ◽  
Andrius Platakis
Keyword(s):  
Experimental Investigation ◽  
Optimal Design ◽  
Design Optimization ◽  
Output Power ◽  
Leakage Flux ◽  
Maximal Output Power ◽  
Maximal Output ◽  
Transformer Design ◽  
The Impact ◽  
Flux Leakage

Results of experimental investigation and design optimization of flyback transformer are presented. Aim of the work is to investigate experimentally the impact of the flyback transformer design on the flux leakage and maximal output power. It is difficult to evaluate the effect of the leakage flux mathematically because it depends on various factors: the position of the windings relative to each other; the position of the windings in the transformer; the distance between the winding. A multi-winding flyback transformer was used for experiments. Using the results of the experiments optimal design of the investigated flyback transformer was defined.

scholarly journals Experiments and Electromechanical Properties of a Broadband Piezoelectric Vibration Energy Harvester

2016 ◽  
Vol 2016 ◽  
pp. 1-14
Author(s):  
Guangqing Wang ◽  
Shuaishuai Gao ◽  
Xiaojun Li
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Short Circuit ◽  
Open Circuit ◽  
Vibration Energy Harvester ◽  
Frequency Space ◽  
Piezoelectric Energy ◽  
Lumped Parameter ◽  
Maximal Output ◽  
Two Peaks

A broadband piezoelectric energy harvester (BPEH), consisting of a conventional linear piezoelectric energy harvester (CPEH) and an elastic magnifier, was presented in this paper. The improved two-degree-of-freedom lumped-parameter electromechanical model of the BPEH was established and the optimal external resistances under short-circuit and open-circuit resonance conditions were investigated to maximize the output power of the BPEH. The output voltage and output power of the BPEH obtained from the theoretical model were verified and found to be in reasonable agreement with the experimental results. The obtained results have shown that the maximal output powers under short-circuit and open-circuit resonance conditions are both 24 times that generated by the CPEH without elastic magnifier. The frequency space between the two peaks of the frequency-response curve of the BPEH is 14 Hz which is 7 times that of CPEH.

scholarly journals A Proposal for an MPPT Algorithm Based on the Fluctuations of the PV Output Power, Output Voltage, and Control Duty Cycle for Improving the Performance of PV Systems in Microgrid

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4326
Author(s):  
Nguyen Van Tan ◽  
Nguyen Binh Nam ◽  
Nguyen Huu Hieu ◽  
Le Kim Hung ◽  
Minh Quan Duong ◽  
...  
Keyword(s):  
Output Power ◽  
Duty Cycle ◽  
Maximum Power Point Tracking ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Ambient Conditions ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point

In microgrids, distributed generators that cannot be dispatched, such as a photovoltaic system, need to control their output power at the maximum power point. The fluctuation of their output power should be minimized with the support of the maximum power point tracking algorithm under the variation of ambient conditions. In this paper, a new maximum power point tracking method based on the parameters of power deviation (ΔPPV), voltage difference (ΔVPV), and duty cycle change (ΔD) is proposed for photovoltaic systems. The presented algorithm achieves the following good results: (i) when the solar radiance is fixed, the output power is stable around the maximum power point; (ii) when the solar radiance is rapidly changing, the generated power is always in the vicinity of maximum power points; (iii) the effectiveness of energy conversion is comparable to that of intelligent algorithms. The proposed algorithm is presented and compared with traditional and intelligent maximum power point tracking algorithms on the simulation model by MATLAB/Simulink under different radiation scenarios to prove the effectiveness of the proposed method.

High Power Mid-Infrared Interband Cascade Lasers

1997 ◽  
Vol 484 ◽  
Author(s):  
B. H. Yang ◽  
D. Zhang ◽  
Rui. Q. Yang ◽  
C.-H. Lin ◽  
S. J. Murry ◽  
...  
Keyword(s):  
Output Power ◽  
High Power ◽  
Duty Cycle ◽  
Average Output Power ◽  
Repetition Rate ◽  
Average Output ◽  
Mid Infrared ◽  
Optical Output ◽  
Interband Cascade Lasers ◽  
Cascade Lasers

AbstractWe have demonstrated 4-μm InAs/InGaSb/AlSb interband cascade lasers with optical output power close to 0.5 W per facet with 1-μs pulses at 1 kHz repetition rate. At 10% duty cycle, an average output power ∼20 mW was realized. External and internal quantum efficiencies exceeding 200% have been achieved at 80 K.

Design and implementation of a measurement system for automatically measurement of electrical parameters of thermoelectric generators

2013 ◽  
Vol 1490 ◽  
pp. 191-196
Author(s):  
Dmitry Petrov ◽  
Fabian Assion ◽  
Ulrich Hilleringmann
Keyword(s):  
Measurement System ◽  
Measurement Data ◽  
Electrical Current ◽  
Graphical Form ◽  
Thermoelectric Generators ◽  
Electrical Parameters ◽  
Electrical Measurements ◽  
Maximal Output Power ◽  
Maximal Output ◽  
Load Resistor

ABSTRACTThe continues development of thermoelectric generators causes a permanent improvement of their characteristics. New types of thermoelectric generators can work at temperatures up to 1000 K. With this, special measurement equipment is needed to control the electrical parameters of the new developed specimens. The devices must be tested over the whole range of operating temperatures. For each temperature value a series of electrical measurements has to be performed. To establish the maximal output power of the thermoelectric generators, a load resistor with variable resistance has to be connected to the output of thermoelectric generator. The measurement system should measure the electrical current through the load resistor and the voltage over this resistor to determine the device parameters. A large amount of measurement data have to be collected and processed to evaluate the electrical characteristics of the specimen and to present them in graphical form, suitable for the comparison with others specimens.

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