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Tytuł:
Performance evaluation of ZVS/ZCS high efficiency AC/DC converter for high power applications
Autorzy:
Ali, A.
Chuanwen, J.
Khan, M. M.
Habib, S.
Ali, Y.
Powiązania:
https://bibliotekanauki.pl/articles/200472.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
switching losses
zero current switching
zero voltage switching
power quality
reverse recovery loss
Opis:
The increased power density, reduced switching losses with minimum electromagnetic interference (EMI), and high efficiency are essential requirements of power converters. To achieve these characteristics, soft power converters employing soft switching techniques are indispensable. In this paper, a ZCS/ZVS PWM AC/DC converter topology has been emphasized, which finds applications in high power systems such as automobile battery charging and renewable energy systems. This converter scheme maintains zero current and zero voltage switching conditions at turn on and turn off moments of semiconductor switches, respectively and soft operation of rectifier diodes that lead to negligible switching and diode reverse recovery losses. Moreover, it improves power quality and presents high input power factor, low total harmonic distortion of the input current (THDI ) and improved efficiency. The validity of theoretical analysis of the proposed converter has been carried out experimentally on a 10 kW laboratory prototype. Experimental results prove that the soft switching operation of the semiconductor switches and diodes is maintained at 98.6% rated load efficiency. In addition, the performance evaluation has been performed by comparative analysis of the proposed converter with some prior art high power AC/DC converters. Efficiencies of the proposed and prior art high power topologies have been determined for different load conditions. The highest efficiency, power factor and lower THDI of the proposed converter topology complies with international standards.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 793-807
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Product robustness philosophy – a strategy towards zero variation manufacturing (ZVM)
Autorzy:
Boorla, M. S.
Eifler, T.
McMahon, C.
Howard, T. J.
Powiązania:
https://bibliotekanauki.pl/articles/406976.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
product robustness
variation absorption
product maturation
zero variation manufacturing
Industry 4.0
production readiness
Opis:
A product is referred to as robust when its performance is consistent. In current product robustness paradigms, robustness is the responsibility of engineering design. Drawings and 3D models should be released to manufacturing after applying all the possible robust design principles. But there are no methods referred for manufacturing to carry and improve product robustness after the design freeze. This paper proposes a process of inducing product robustness at all stages of product development from design release to the start of mass production. A manufacturing strategy of absorbing all obvious variations and an approach of turning variations to cancel one another are defined. Verified the application feasibility and established the robustness quantification method at each stage. The theoretical and actual sensitivity of different parameters is identified as indicators. Theoretical and actual performance variation and accuracy of estimation are established as robustness metric. Manufacturing plan alignment to design, complimenting the design and process sensitivities, countering process mean shifts with tool deviations, higher adjustable assembly tools are enablers to achieve product robustness.
Źródło:
Management and Production Engineering Review; 2018, 9, 2; 3-12
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feedback saddle point equilibria for soft-constrained zero-sum linear quadratic descriptor differential game
Autorzy:
Musthofa, M. W.
Salmah, ---
Engwerda, J. C.
Suparwanto, A
Powiązania:
https://bibliotekanauki.pl/articles/964027.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
soft-constrained zero-sum linear quadratic differential game
feedback information structure
descriptor systems
Opis:
In this paper the feedback saddle point equilibria of soft-constrained zero-sum linear quadratic differential games for descriptor systems that have index one will be studied for a finite and infinite planning horizon. Both necessary and sufficient conditions for the existence of a feedback saddle point equilibrium are considered.
Źródło:
Archives of Control Sciences; 2013, 23, 4; 473-493
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of 4-chlorophenol from aqueous solution by granular activated carbon/nanoscale zero valent iron based on Response Surface Modeling
Autorzy:
Majlesi, M.
Hashempour, Y.
Powiązania:
https://bibliotekanauki.pl/articles/205422.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
response surface methodology
4-chlorophenol
NZVI/AC
activated carbon
nano zero-valent iron
Opis:
The phenolic compounds are known as priority pollutants, even in low concentrations, as a result of their toxicity and non-biodegradability. For this reason, strict standards have been established for them. In addition, chlorophenols are placed in the 38th to 43th in highest priority order of toxic pollutants. As a consequence, contaminated water or wastewaters with phenolic compounds have to be treated before discharging into the receiving water. In this study, Response Surface Methodology (RSM) has been used in order to optimize the effect of main operational variables responsible for the higher 4-chlorophenol removal by Activated Carbon-Supported Nanoscale Zero Valent Iron (AC/NZVI). A Box-Behnken factorial Design (BBD) with three levels was applied to optimize the initial concentration, time, pH, and adsorbent dose. The characterization of adsorbents was conducted by using SEM-EDS and XRD analyses. Furthermore, the adsorption isotherm and kinetics of 4-chlorophenol on AC and AC/NZVI under various conditions were studied. The model anticipated 100% removal efficiency for AC/NZVI at the optimum concentration (5.48 mg 4-chlorophenol/L), pH (5.44), contact time (44.7 min) and dose (0.65g/L). Analysis of the response surface quadratic model signified that the experiments are accurate and the model is highly significant. Moreover, the synthetic adsorbent is highly efficient in removing of 4-chlorophenol.
Źródło:
Archives of Environmental Protection; 2017, 43, 4; 13-25
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A zero-dimensional model used as a basis for numerical modelling of OP-650 boiler
Zerowymiarowy model kotła jako podstawa do obliczeń numerycznych kotła OP 650
Autorzy:
Hernik, B.
Pronobis, M.
Powiązania:
https://bibliotekanauki.pl/articles/172845.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power boiler
OP650 boiler
zero-dimensional model
CFD modelling
numerical modelling
kocioł energetyczny
kocioł OP-650
model zero-wymiarowy
modelowanie CFD
modelowanie numeryczne
Opis:
The numerical modelling of power boiler furnaces is often performed in the engineering practice. Quite often, however, the balance calculations of the entire boiler are not carried out. In this case, the flue gas temperature at the furnace outlet results from the numerical model and depends on the adopted assumptions (e.g. wall fouling or emissivity). However, the value determined in this way may be wrong, and the presented calculation method makes it impossible to verify it. One of the ways to improve the numerical model accuracy is the verification of the flue gas temperature at the furnace outlet value by calculations fully balanced by a zero-dimensional (0D) model based on measuring data. The numerical calculations should be carried in such a way that the average temperature at the furnace outlet in the computational fluid dynamical (CFD) model equals the temperature obtained from the 0D model. At the same time, the matching of this temperature should result from carefully selected assumptions of the numerical model, which have to correspond to the actual phenomena occurring in the furnace. This model presents the verification of the CFD model for the OP-650 boiler of a 225 MWel power unit. The results of numerical modelling of boiler according to non-premixed combustion model with mixture fraction/PDF (probability density function) approach was presented. Also numerical modelling of boiler with species transport model with volumetric reactions and finite rate chemistry was done.
W praktyce inżynierskiej często wykonywane jest numeryczne modelowanie palenisk kotłów energetycznych, przy czym często nie prowadzi się obliczeń bilansowych całego kotła. Temperatura spalin na wylocie z paleniska wynika wówczas z modelu numerycznego i zależy od przyjętych założeń (np. zanieczyszczenie ścian lub ich emisyjność). Tak wyznaczona wartość temperatury może jednak być błędna, a opisany sposób liczenia uniemożliwia jej weryfikację. Sposobem na poprawę dokładności modelu numerycznego jest weryfikacja temperatury spalin na wylocie z paleniska za pomocą w pełni zbilansowanych obliczeń modelem 0-wymiarowym opartym na danych pomiarowych. Obliczenia numeryczne powinny być tak prowadzone, aby średnia temperatura na wylocie z komory paleniskowej kotła w modelu CFD była równa temperaturze uzyskanej z modelu zerowymiarowego. Jednocześnie dopasowanie tej temperatury powinno wynikać z odpowiednio dobranych założeń modelu numerycznego, które muszą odpowiadać realnemu przebiegowi zjawisk zachodzących w palenisku. W niniejszej pracy dokonano opisanej weryfikacji modelu CFD dla kotła OP 650 do bloku 225 MWel. Przedstawiono wyniki modelowania numerycznego kotła wg algorytmu mixture fraction/PDF - z wykorzystaniem modelu spalania non-premixed oraz wyniki dla modelu opartego na reakcjach objętościowych z wykorzystaniem modelu finite-rate/eddy-dissipation.
Źródło:
Archiwum Energetyki; 2012, 42, 2; 17-26
0066-684X
Pojawia się w:
Archiwum Energetyki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and Experimental Validation of a Correlation Monitor Tool Based on the Endogenous Pulsed Neutron Source Technique
Autorzy:
Arkani, M.
Khalafi, H.
Vosoughi, N.
Khakshournia, S.
Powiązania:
https://bibliotekanauki.pl/articles/221446.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
endogenous pulsed neutron source experiment
neutron noise fluctuation
zero power reactor noise
Esfahan heavy-water zero power reactor
neutron correlation
Opis:
A correlation measuring tool for an endogenous pulsed neutron source experiment is developed in this work. Paroxysmal pulses generated by a bursts of neutron chains are detected by a 10-kbit embedded shift register with a time resolution of 100 ns. The system is implemented on a single reprogrammable device making it a compact, cost-effective instrument, easily adaptable for any case study. The system was verified experimentally in the Esfahan heavy-water zero power reactor (EHWZPR). The results obtained by the measuring tool are validated by the Feynman-α experiment, and a good agreement is seen within the boundaries of statistical uncertainties. The theory of the methods is briefly initiated in the text. Also, the system structure is described, the experimental results and their uncertainties are discussed, and neutron statistics in EHWZPR is examined experimentally.
Źródło:
Metrology and Measurement Systems; 2017, 24, 3; 441-461
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an embedded FPGA-based data acquisition system dedicated to zero power reactor noise experiments
Autorzy:
Arkani, M.
Khalafi, H.
Vosoughi, N.
Powiązania:
https://bibliotekanauki.pl/articles/220709.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
zero power reactor (ZPR) noise
time interval measurement
probability distribution function (PDF)
field programmable gate array (FPGA)
data acquisition system (DAS)
nuclear reactor
neutron detection
Opis:
An embedded time interval data acquisition system (DAS) is developed for zero power reactor (ZPR) noise experiments. The system is capable of measuring the correlation or probability distribution of a random process. The design is totally implemented on a single Field Programmable Gate Array (FPGA). The architecture is tested on different FPGA platforms with different speed grades and hardware resources. Generic experimental values for time resolution and inter-event dead time of the system are 2.22 ns and 6.67 ns respectively. The DAS can record around 48-bit x 790 kS/s utilizing its built-in fast memory. The system can measure very long time intervals due to its 48-bit timing structure design. As the architecture can work on a typical FPGA, this is a low cost experimental tool and needs little time to be established. In addition, revisions are easily possible through its reprogramming capability. The performance of the system is checked and verified experimentally.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 433-446
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorithm for solving the Discrete-Continuous Inspection Problem
Autorzy:
Grymin, R.
Bożejko, W.
Chaczko, Z.
Pempera, J.
Wodecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/1403679.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
discrete-continuous optimization
UAV
VTOL
autonomous drone
zero emission
Opis:
The article introduces an innovative approch for the inspection challenge that represents a generalization of the classical Traveling Salesman Problem. Its priciple idea is to visit continuous areas (circles) in a way, that minimizes travelled distance. In practice, the problem can be defined as an issue of scheduling unmanned aerial vehicle which has discrete-continuous nature. In order to solve this problem the use of local search algorithms is proposed.
Źródło:
Archives of Control Sciences; 2020, 30, 4; 653-666
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of the advanced zero emission power plant
Autorzy:
Kotowicz, J.
Job, M.
Powiązania:
https://bibliotekanauki.pl/articles/240797.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AZEP
gas turbine
membrane reactor
oxy-combustion
CCS
turbina gazowa
reaktor membranowy
spalanie w tlenie
Opis:
The paper presents the structure and parameters of advanced zero emission power plant (AZEP). This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i) oxygen separation from the air through the membrane, (ii) combustion of the fuel, and (iii) heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC) through the main heat recovery steam generator (HRSG). Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.
Źródło:
Archives of Thermodynamics; 2016, 37, 1; 87-98
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Noise Analysis of a Novel Auto-Zeroing Structure for Continuous-Time Instrumentation Amplifiers
Autorzy:
Maréchal, S.
Nys, O.
Krummenacher, F.
Chevroulet, M.
Kayal, M.
Powiązania:
https://bibliotekanauki.pl/articles/226106.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
front-end
instrumentation amplifier
low-noise
low power
chopper
auto-zero
Opis:
This paper introduces a low-noise, low-power amplifier for high-impedance sensors. An innovative circuit using an auto-zeroed architecture combined with frequency modulation to reject offset and low-frequency noise is proposed and analysed. Special care was given to avoid broadband noise aliasing and chopping in the signal path, and to minimize both the resulting equivalent input offset voltage and equivalent input biasing current. The theoretical noise analysis of the proposed topology covers most of the noise sources of the circuit. Simulations show that the input-referred noise level of the circuit is 13.4nV/√Hz for a power consumption of 85µA with a power supply from 1.8V to 3.6V.
Źródło:
International Journal of Electronics and Telecommunications; 2013, 59, 4; 397-404
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal selection of inner-branches parameters of matching circuits under the minimum branch-current RMS values and zero active-power conditions
Autorzy:
Jaraczewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/201906.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multi-terminal-network compensators
optimization
nonlinear load
Opis:
The article is a continuation of a study on the synthesis of matching multi-terminal networks, also known as compensators. The reactive four-terminal-network compensators for linear loads were introduced in previous publications, but it appeared they operate effectively with nonlinear loads too. The methods to create a compensator for a mono-harmonic source, which allows complete independence of the input from output waveforms, ensuring optimal operating conditions for the source, are presented herein. The work for the first time presents the optimal four-terminal-network compensator applied to a nonlinear load.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 777-783
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Disturbance attenuation problem using a differential game approach for feedback linear quadratic descriptor systems
Autorzy:
Musthofa, M. W.
Powiązania:
https://bibliotekanauki.pl/articles/229177.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
disturbance attenuation problem
zero-sum linear quadratic differential game
descriptor systems
feedback information structure
Opis:
This paper studies the H∞ disturbance attenuation problem for index one descriptor systems using the theory of differential games. To solve this disturbance attenuation problem the problem is converted into a reduced ordinary zero-sum game. Within a linear quadratic setting the problem is solved for feedback information structure.
Źródło:
Archives of Control Sciences; 2015, 25, 4; 445-462
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of zero-dimensional model of SOFC with internal fuel reforming for complex hybrid energy cycles
Autorzy:
Badur, J.
Lemański, M.
Kowalczyk, T.
Ziółkowski, P.
Kornet, S.
Powiązania:
https://bibliotekanauki.pl/articles/184970.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuel cell
SOFC
mathematical model
experiment
verification
ogniwo paliwowe
model matematyczny
eksperyment
weryfikacja
Opis:
The article presents a zero-dimensional mathematical model of a tubular fuel cell and its verification on four experiments. Despite the fact that fuel cells are still rarely used in commercial applications, their use has become increasingly more common. Computational Flow Mechanics codes allow to predict basic parameters of a cell such as current, voltage, combustion composition, exhaust temperature, etc. Precise models are particularly important for a complex energy system, where fuel cells cooperate with gas, gas-steam cycles or ORCs and their thermodynamic parameters affect those systems. The proposed model employs extended Nernst equation to determine the fuel cell voltage and steadystate shifting reaction equilibrium to calculate the exhaust composition. Additionally, the reaction of methane reforming and the electrochemical reaction of hydrogen and oxygen have been implemented into the model. The numerical simulation results were compared with available experiment results and the differences, with the exception of the Tomlin experiment, are below 5%. It has been proven that the increase in current density lowers the electrical efficiency of SOFCs, hence fuel cells typically work at low current density, with a corresponding efficiency of 45–50% and with a low emission level (zero emissions in case of hydrogen combustion).
Źródło:
Chemical and Process Engineering; 2018, 39, 1; 113--128
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Simulation of a Room Temperature HgCdTe Long-Wave Detector for Fast Response - Operating Under Zero Bias Conditions
Autorzy:
Martyniuk, P.
Kopytko, M.
Madejczyk, P.
Henig, A.
Grodecki, K.
Gawron, W.
Rutkowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/221111.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
response time
unbiased condition
HgCdTe
LWIR
higher operating temperature
Opis:
The paper reports on a long-wave infrared (cut-off wavelength ~ 9 μm) HgCdTe detector operating under nbiased condition and room temperature (300 K) for both short response time and high detectivity operation. The ptimal structure in terms of the response time and detectivity versus device architecture was shown. The response time of the long-wave (active layer Cd composition, xCd = 0.19) HgCdTe detector for 300 K was calculated at a level of τs ~ 1 ns for zero bias condition, while the detectivity - at a level of D* ~ 109 cmHz1/2/W assuming immersion. It was presented that parameters of the active layer and P+ barrier layer play a critical role in order to reach τs ≤ 1 ns. An extra series resistance related to the processing (RS+ in a range 5-10 Ω) increased the response time more than two times (τs ~ 2.3 ns).
Źródło:
Metrology and Measurement Systems; 2017, 24, 4; 729-738
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the harmonic composition of current in the zero-working wire at the input of the load node with the prevailing non-linear power consumers
Autorzy:
Yudaev, Igor V.
Rud, Evgeny V.
Yundin, Mikhail A.
Ponomarenko, Tamara Z.
Isupowa, Aleksandra M.
Powiązania:
https://bibliotekanauki.pl/articles/1841306.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
harmonic currents
non-linear power receiver
non-symmetry
three-phase fourwire network
zero working wire of the network
prądy harmoniczne
nieliniowy odbiornik mocy
niesymetria
sieć trójfazowa czteroprzewodowa
zerowy przewód roboczy sieci
Opis:
Due to the extensive use of nonlinear power consumers, there is currently an urgent problem of high harmonic content in power supply networks. The paper provides experimental investigations and a study of the nature of the change in the main harmonic components of the current in the neutral working wire of a three-phase four-wire network with a voltage of 0.38 kV. The purpose of this study is to compare the load readings on the amplitude-phase-frequency characteristics of the current in the neutral working wire of the 0.38 kV network with the linear and non-linear load. To study the effect of load changes on the amplitude-phase-frequency characteristics of currents in the linear and zero working wires at the input of the load node, measurements were carried out by certified electrical measuring instruments. The analysis of the results obtained for the load node whose power was formed mainly by a lighting system with fluorescent and LED lamps and a system of office electrical receivers (computers, copiers, printers, scanners, etc.) was performed. It can be concluded that a current comparable to the currents of the linear wires of the network flows from the load node with the predominant nonlinear power receivers through the zero-working wire. At the same time, in the zero-working wire of the network, the third harmonic currents prevail over the main frequency currents.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 463-473
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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