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Wyszukujesz frazę "high power" wg kryterium: Temat


Tytuł:
Analysis and optimization of outputs of high power microwave tubes
Autorzy:
Węgrzyniak, P.
Gwarek, W.
Baczewski, D.
Powiązania:
https://bibliotekanauki.pl/articles/307618.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
high power microwave tubes
optimization of outputs
Opis:
The subject of this work is optimization of outputs of L-band high power microwave tubes. These outputs are constructed as coaxial-to-waveguide transitions with a vacuum barrier in a form of glass or ceramic cup. The goal of optimization is to obtain sufficiently low reflection loss in the predefined frequency band and to avoid so called hot spots caused by excessive dissipation of microwave power in parts of the cup. Electromagnetic simulator has been applied to model the behavior of the optimized transition and to propose its optimum shape. The proposed solutions were verified by Z.E. Lamina SA in prototypes of high power (pulsed 600 kW) amplitrons and are to be used in manufacturing practice.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 1; 35-39
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission characteristics of the mobile inductively coupled power transfer system for dual transmitters and pickups based on PSpice
Autorzy:
Gao, Xin
Li, Xin
Powiązania:
https://bibliotekanauki.pl/articles/141475.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high power
ICPT
LCL compensation network
mobile
PSpice
Opis:
In order to meet the application requirements of high-power mobile inductivelycoupled power transfer (ICPT) equipment, the structure of the dual transmitter and pickup can be used to improve the transmission power of the ICPT system. However, this structure cannot easily describe the change of the mutual inductance parameter in the moving state, making the mathematical model difficult to establish. The change of load parameters during the movement will affect the current and voltage at the transmitter and pickup coils. Aiming at these problems, this paper proposes a dual transmitter and pickup ICPT system based on inductor-capacitor-inductor (LCL) compensation network, and analyzes its power transmission efficiency. By setting the shape and size of the coil, the influence of the change of the mutual inductance parameters on the system efficiency during the movement is reduced. The changes of the mutual inductance parameters of the ICPT system under the moving state are simulated by changing the coupling coefficient in the PSpice software. The results show that the structure of the ICPT system used in this paper can improve the output power and reduce the influence of the system when the load changes.
Źródło:
Archives of Electrical Engineering; 2020, 69, 1; 147-157
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Method Of Calculating Thermal Diffusivity And Conductivity For Irregularly Shaped Specimens In Laser Flash Analysis
Autorzy:
Szałapak, J.
Kiełbasiński, K.
Krzemiński, J.
Młożniak, A.
Zwierkowska, E.
Jakubowska, M.
Pawłowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/220433.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal diffusivity
LFA
LTJT joints
high power electronics
Opis:
The Low Temperature Joining Technique (LTJT) using silver compounds enables to significantly increase the thermal conductivity between joined elements, which is much higher than for soldered joints. However, it also makes difficult to measure the thermal conductivity of the joint. The Laser Flash Analysis (LFA) is a non-intrusive method of measuring the temperature rise of one surface of a specimen after excitation with a laser pulse of its other surface. The main limitation of the LFA method is its standard computer software, which assumes the dimensions of a bonded component to be similar to those of the substrate, because it uses the standard Parker’s formula dedicated for one-dimensional heat flow. In the paper a special design of measured specimen was proposed, consisting of two copper plates of different size joined with the sintered silver layer. It was shown that heat properties of these specimens can also be measured after modifying the LFA method. The authors adapted these specimens by masking the false heat signal sourced from the uncovered plate area. Another adaptation was introducing a correcting factor of the heat travel distance, which was calculated with heat-flow simulations and placed into the Parker’s formula. The heat-flow simulated data were compared with the real LFA measurement results, which enabled estimation of the joint properties, e.g. its porosity.
Źródło:
Metrology and Measurement Systems; 2015, 22, 4; 521-530
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation into Increasing the Motor-Drivable Current Using a Thermoelectric Cooling Module
Autorzy:
Morikawa, Kazuma
Katsura, Seiichiro
Powiązania:
https://bibliotekanauki.pl/articles/2175939.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
motor
cooling
thermoelectric effect
Peltier device
high power
Opis:
To enhance the performance of humanoids, mobile robots and manipulators, motors are desired to be able to provide high torque without relying on gears. To be able to drive joint motors with high output, the current value that can flow needs to be increased. However, the heat generated by the high current drive can cause motor failure, so cooling is necessary. We used thermoelectric cooling as a new cooling method for high-power drive of motors. By developing a thermoelectric cooling module for motors and conducting experiments, the effectiveness of thermoelectric cooling was verified. In the experiment, the motor was kept running at a high current for a long period of time. The comparison with the motor alone or with water cooling showed that the thermoelectric cooling module can significantly reduce the rise in temperature of the motor. Furthermore, based on the results of the voltage value measurements, it was expected that the increase in coil resistance due to higher coil temperatures would be kept lower than in other cases. The effect on rise in internal temperature was also considered to be greater than that of water cooling. These experimental results show that the thermoelectric cooling module can be used to increase the upper limit of the current at which the motor is continuously driven.
Źródło:
Power Electronics and Drives; 2022, 7, 42; 279--289
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power quality enhancement of three-phase front-end rectifier of UPS system using current injection technique
Autorzy:
Dhomane, G. A.
Suryawanshi, H.
Powiązania:
https://bibliotekanauki.pl/articles/262756.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
high frequency current injection
high power factor
soft transition
power factor correction circuit
Opis:
Power Quality, in terms of power factor and harmonics, is greatly hampered by a three-phase rectifier used as a front-end ac-to-dc converter in many systems including a UPS. This paper presents the high power factor operation of the converter with reduced total harmonic distortion up to 4%. The power quality up gradation is due to high-frequency current injection, at the input of the front-end rectifier. A small filter is required at the output for filtering the high-frequency content. Sinusoidal PWM technique is used for controlling the output voltage. DSP is used for generating the desired gate pulses. The converter has high efficiency, low EMI emissions, high power packing density and suitable for UPS system. A Simulation and experimentation is carried out on a 3 kW converter and experimental results are in good agreement with simulation results.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 2; 35-39
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zagadnienia optymalizacji konstrukcji diod laserowych dużej mocy
High power laser diodes - design optimisation issues
Autorzy:
Malag, A.
Powiązania:
https://bibliotekanauki.pl/articles/192142.pdf
Data publikacji:
2007
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Materiałów Elektronicznych
Tematy:
dioda laserowa dużej mocy
konstrukcja diod laserowych dużej mocy
optymalizacja wiązki promieniowania
high power laser diodes
high power laser diodes construction
Opis:
Artykuł zawiera skrótowy przegląd aktualnych osiągnięć w dziedzinie konstrukcji diod laserowych (DL) dużej mocy. Zakres artykułu ograniczony został do zagadnień optymalizacji heterostruktury ze względu na parametry, które wydają się najważniejsze dla przyrządów dużej mocy takie, jak sprawność energetyczna (PCE), próg katastroficznej degradacji luster (COD) i jakość emitowanej wiązki promieniowania (M2 i rozbieżność). Przedstawione wyniki (przodujących instytutów i ITME) wskazują, że jednoczesna maksymalizacja wszystkich tych parametrów jest bardzo trudna. Wyniki "rekordowe" są bardzo zróżnicowane ze względu na długość fali i grupę materiałową (arsenki, fosforki).
Current achievements in the field of high-power laser diodes (LD) construction are briefly presented. The scope has been limited to issues of heterostructure optimisation in terms of the parameters the most important for high power devices, such as power conversion efficiency (PCE), COD level and an emitted beam quality (M2 and divergence). Presented results (of leading laboratories and ITME) indicate that simultaneous maximisation of these parameters is very difficult. There is a wide diversity of the record-high attainments in terms of preferred design solutions and due to different wavelengths and material systems.
Źródło:
Materiały Elektroniczne; 2007, T. 35, nr 1, 1; 21-46
0209-0058
Pojawia się w:
Materiały Elektroniczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design methods for limiting rotor losses in a fractional slot PMSM motor with high power density
Autorzy:
Wolnik, Tomasz
Opach, Szczepan
Cyganik, Łukasz
Jarek, Tomasz
Szekeres, Vojtech
Powiązania:
https://bibliotekanauki.pl/articles/2172802.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fractional slot motors
high power density motor
rotor losses
Opis:
Fractional slot PMSM motors enable high power density factors to be obtained provided that their electromagnetic circuit, appropriate mechanical structure and cooling system are properly designed, as well as when operating at a high frequency of power supply voltage (400–800 Hz) with high magnetic saturation and high current loads (approx. 12–15 A/mm2). Such operating conditions, especially in the case of fractional slot motors, may be the reason for excessive rotor losses, mainly in the rotor yoke and permanent magnets. One of the conditions for obtaining high values of continuous power of the motor is the reduction of these losses. This paper presents selected design methods for limiting the value of rotor losses with simultaneous consideration of their influence on other motor parameters. The analysiswas carried out for a PMSM motor with an external rotor weighting approx. 10 kg and a maximum power of 50 kW at a rotational speed of 4 800 rpm.
Źródło:
Archives of Electrical Engineering; 2022, 71, 4; 963--979
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Computer-controlled System of High-power Microwave Sources
Autorzy:
Korpas, P.
Gryglewski, D.
Wojtasiak, W.
Gwarek, W.
Powiązania:
https://bibliotekanauki.pl/articles/226529.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
SiC
GaN
high power amplifier
PLL synthesizer
microwave sources
Opis:
The paper presents the design and hardware implementation of a computer controlled system composed of up to four high-power microwave sources. Each source provides up to 200 W of continuous wave power. Frequency of each source is stabilized within ±0.5 ppm of the nominal frequency adjustable within 2.35÷2.6 GHz range. All four sources can be synchronized to the same frequency with computer-controlled phase shift between the signals generated by each of them. The paper concentrates on the choice of components for such a system and the properties of the realized hardware implementation.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 121-126
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A 100 W SiC MESFET Amplifier for L-band T/R Module of APAR
Autorzy:
Wojtasiak, W.
Gryglewski, D.
Powiązania:
https://bibliotekanauki.pl/articles/226539.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high power amplifier
SiC
MESFET
T/R module
APAR
Opis:
In the paper, a 100W SiC MESFET amplifier design dedicated for a L-band T/R module of APAR is presented. The output power higher than 100 W has been achieved by combining in a balanced configuration two single stages with Cree's 60 W CRF24060 SiC MESFETs. The amplifier design methodology is based on the small-signal model and DC characteristics of SiC MESFET. The model is extracted using the transistor Sparameters at three operating points for On-state, Off-state and normally biased. The measurements and simulations prove usefulness of the proposed design method. The amplifier was excited with pulsed and cw signals for the case temperature ranging from 60°C to 140°C. As a result of the case temperature changes the output power drop was lower than 0.5 dB at the level of 150 W.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 135-140
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High power microwave for knocking out programmable suicide drones
Autorzy:
Chaari, Mohamed Zied
Powiązania:
https://bibliotekanauki.pl/articles/1311126.pdf
Data publikacji:
2021
Wydawca:
Akademia Sztuki Wojennej
Tematy:
high power microwave
conical horn antenna
errant drone
kill drone
high frequency
Opis:
The primary research objective is to reduce the dangers of rogue drones in our lives and the consequences of extremist groups, drug dealers, and organised criminals using them. The growing number of incidents involving modified drones proves the weakness of existing technology in stopping and neutralising errant drones such as the hand-held gun jammer, trained eagle, R.F. jammer, and others. This technology is not very likely to able to knock out a rogue drone and is incapable of stopping programmable drones. This article aims to examine the directed energy of HPM (high power microwaves) in using the electromagnetic field strength energy to damage the drone’s structure or burn its PCB board electronics. It goes on to analyse electronic attack using microwave power with high frequency to immediately switch off drones. The effectiveness of high microwave power for disrupting drones at different distances and in different weather conditions is evaluated. A study of the conical horn antenna of the magnetron coupling system, which has an operating frequency of 2.45 GHz, is also included.
Źródło:
Security and Defence Quarterly; 2021, 34, 2; 68-84
2300-8741
2544-994X
Pojawia się w:
Security and Defence Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review and comparison of high efficiency high power boost DC/DC converters for photovoltaic applications
Autorzy:
Dawidziuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/200077.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
boost DC/DC converters
high efficiency
high power
photovoltaic systems
renewable energy
Opis:
Recent environmental issues have accelerated the use of more efficient and energy saving technologies in renewable energy systems. High power high efficiency boost DC/DC converters for the use in photovoltaic, fuel cell systems are discussed in this paper from the viewpoint of power losses and efficiency. State of the art converters with switching frequency within the range of 25 kHz with IGBTs to 100 kHz with power MOSFETs and the highest efficiency close to 98%, depending on the load conditions, is considered. A comparison and discussion of the highest efficiency high power DC/DC boost converters is also presented in this paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 4; 499-506
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Power Laser Laboratory at the Institute of Plasma Physics and Laser Microfusion : equipment and preliminary research
Autorzy:
Zaraś-Szydłowska, A.
Badziak, J.
Rosiński, M.
Makowski, J.
Parys, P.
Piotrowski, M.
Ryć, L.
Wołowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/146603.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
femtosecond pulses
high-power laser
inertial confinement fusion
laser plasma
Opis:
The purpose of this paper is to present the newly-opened High Power Laser Laboratory (HPLL) at the Institute of Plasma Physics and Laser Microfusion (IPPLM). This article describes the laser, the main laboratory accessories and the diagnostic instruments. We also present preliminary results of the first experiment on ion and X-ray generation from laser-produced plasma that has been already performed at the HPLL.
Źródło:
Nukleonika; 2015, 60, 2; 245-248
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study of Susceptibility and Evaluation of Causes of Cracks Formation in Braze-Weld Filler Metal in Lap Joints Aluminum – Carbon Steel Made with Use of CMT Method and High Power Diode Laser
Autorzy:
Adamiak, M.
Wyględacz, B.
Czupryński, A.
Górka, J.
Powiązania:
https://bibliotekanauki.pl/articles/958197.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
braze-welding
intermetallic compound phase
high power diode laser
brazing
Opis:
In this article results of studies on cracks formation susceptibility in braze-welded joints of thin aluminum sheets and double-sided zinc galvanized steel sheets for car body parts made by laser brazing with high power diode laser ROFIN DL 020 and CMT MIG-brazing, with filler material in form of powder and wire accordingly, were presented. Optimal welding parameters were determined by visual acceptance criteria. On joints made with optimal parameters further examinations were carried. Results of macro- and microscopic metallographic examinations, structural roentgenography, EDS microanalysis and hardness tests were presented. Causes of brittle intermetallic Fe-Al phases formation in Al-matrix filler metal in dissimilar aluminum – zinc plated carbon steel joints were pointed.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2113-2123
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
THREE PHASE WARSAW BOOST RECTIFIER FOR HIGH POWER VARIABLE SPEED POWER GENERATION
Trójfazowy „Warsaw Rectifier” w układzie wytwarzania energii dużej mocy o regulowanej prędkości generatora
Autorzy:
Bałkowiec, T.
Powiązania:
https://bibliotekanauki.pl/articles/1817906.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Warsaw rectifier
delta-switch rectifier
high power
PWM modulation
Vienna rectifier
Opis:
Artykuł przedstawia topologię prostownika „Warsaw Rectifier”, jego zasadę działania oraz wyniki symulacyjne, w których prostownik zasilany był ze źródła napięcia o zmiennej amplitudzie i częstotliwości, np. generatora z magnesami trwałymi. Wyniki symulacyjne potwierdzają poprawność opracowanego układu sterowania, opartego na modulacji szerokości impulsów o stałej częstotliwości łączeń. Przedstawione wyniki w tabeli 3 również potwierdzają, że topologia umożliwia pobór sinusoidalnego prądu oraz stabilizację napięcia wyjściowego prostownika w układach o dużej mocy, w których częstotliwość łączeń jest ograniczona. Układ prostownika umożliwia zapewnia małe pulsacje mocy, które w generatorze przekładają się na małe pulsacji momentu. Topologia Warsaw Rectifier jest podobna do topologii Vienna Rectifier, natomiast różni się sposobem połączeń. Co więcej, rozważany prostownik Warsaw Rectifier wytwarza dwupoziomowe napięcie wyjściowe, podczas gdy prostownik Vienna wytwarza stałe, trójpoziomowe napięcie.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2015, 71, 35; 3--15
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formula for temperature distribution in multi-layer optical fibres for high-power fibre lasers
Autorzy:
Grábner, Martin
Peterka, Pavel
Honzátko, Pavel
Powiązania:
https://bibliotekanauki.pl/articles/2063890.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
high-power fibre lasers
active optical fibres
temperature distribution
heat transfer
Opis:
High power fibre lasers need to be cooled efficiently to avoid their thermal damage. Temperature distribution in fibre should be estimated during the fibre laser design process. The steady-state heat equation in a cylindrical geometry is solved to derive a practical formula for temperature radial distribution in multi-layered optical fibres with arbitrary number of the layers. The heat source is located in one or more cylindrical domains. The validity of the analytical formula is tested by comparison with static heat transfer simulations of typical application examples including octagonal double clad fibre, air-clad fibre, fibre with nonuniform, microstructured core. The accuracy sufficient for practical use is reported even for cases with not exactly cylindrical domains.
Źródło:
Opto-Electronics Review; 2021, 29, 4; 126--132
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł

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