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Search results for: POWER SEMICONDUCTOR DEVICES
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Dynamics of cutting power during sawing with circular saw blades as an effect of wood properties changes in the cross section
PublicationIn the paper the effect of the method calculation upon the cutting power is presented. In computations were used models in which fracture toughness was incorporated. The comparison concerned models as follows: FM-CM – classic model in which the sum of all uncut chip thicknesses of the simultaneously teeth engaged represented the mean uncut chip thickness, FM-FDM – full dynamical model in which besides variable uncut chip thickness...
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A simple modular active power electronic transformer
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The influence of adsorption chillers on CHP power plants
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Integration adsorption chillers with conventional power plant
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Destruction assessment of wind power plastics blade
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Selected problems of high-power sonar sources
PublicationSpecyfika pracy współczesnych sonarów aktywnych wymaga cyklicznego wypełnienia energią szerokiego sektora sondowania. W przypadku użycia płaskich anten nadawczych oznacza to zwykle konieczność skupienia energii akustycznego impulsu nadawczego na stosunkowo małej powierzchni czynnej przetwornika elektroakustycznego (kluczowe znaczenie odgrywa tu częstotliwość pracy systemu). Zjawiska towarzyszące dużym poziomom źródła mogą powodować...
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Analysis of reliability of redundant ship power plants
PublicationW referacie przedstawiono możliwości wykorzystania teorii procesów semimarkowskich do określania charakterystyk niezawodnościowych złożonych układów napędowych o zadanym stopniu redundancji. Na przykładzie wybranego układu zaproponowano model niezawodnościowy w formie procesu stochastycznego dyskretnego w stanach i ciągłego w czasie. W oparciu o rozkład graniczny procesu wskazano na praktyczne aspekty wykorzystania uzyskanych w...
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Measurement of the muon stopping power in lead tungstate
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How Good are the Design Tools in Power Electronics?
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Novel Design of an Ocean Wave Power Device
PublicationW artykule przedstawiono nowoczesną boję energetyczną o opatentowanej konstrukcji. Omówiono jej konstrukcję oraz przedstawiono problemy konstrukcyjne i badawcze. W ostatniej części artykułu przedstawiono wyniki badań wykonanych na modelu w basenie modelowym.
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Wind farms influence on power system stability
PublicationW artykule przedstawiono analizę wpływu elektrowni i farm wiatrowych na stabilność systemu elektroenergetycznego. Pokazano wyniki pomiarów modów kołysań elektromechanicznych wykonanych w rzeczywistym systemie elektroenergetycznym.
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CM Voltage Compensators for Power Electronic Interfaces
PublicationThe experimental results presented in the paper have shown that the application of the PEIs might cause EMC related problems, especially in the case of the application of a group of connected converters. The most convenient way to reduce EMI currents and prevent aggregation of EMI currents introduced by a group of converters is through passive compensation of voltage interference sources inside of the single converters. In the...
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Fuel systems of high power stationary engine
PublicationThe use of alternative fuels and, in the future, synthetic fuels has forced changes in the design of fuel supply systems in internal combustion engines. When operating a stationary engine at constant load, the possibility of using lean fuel mixtures appears. The selection of a precise operating mixture ignition system requires changes in traditional fuel systems. The article presents the current designs of fuel supply systems and...
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Dependence of Power Characteristics on Savonius Rotor Segmentation
PublicationSavonius rotors are large and heavy because they use drag force for propulsion. This leads to a larger investment in comparison to horizontal axis wind turbine (HAWT) rotors using lift forces. A simple construction of the Savonius rotor is preferred to reduce the production effort. Therefore, it is proposed here to use single-segment rotors of high elongation. Nevertheless, this rotor type must be compared with a multi-segment...
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HYDROSTATIC THRUST BEARING WITH REDUCED POWER LOSSES
PublicationIn many cases in rotating machinery, axial load is carried by tilting pad thrust bearings which have been developed since the beginning of 20th century. For high reliability and simplicity, most commonly the bearings are bath lubricated. In the times of sustainable development, however, minimization of friction losses becomes an important criterion for machinery assessment, and a strategic goal of their development. Performed calculations,...
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A boost topology active power factor corrector.
PublicationPrzedstawiono układ analogowego aktywnego korektora zbudowanego na układzie scalonym kontrolera PWM oraz tranzystorem MOS jako okresowo przełączonym kluczem. Układ korektora zapewnia pobór prądu z sieci energetycznej w postaci przebiegu prawie sinusoidalnego o małych zniekształceniach i w fazie z sinusoidalnym napięciem sieci.
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Isolation and restoration policies against power collapse.
PublicationPrzedstawiono zasady obrony systemów elektroenergetycznych przed tzw. blackout´em. Omówiono wielkości kryterialnych tych systemów, możliwości predykcji stanów zagrożeniowych oraz automatyki działające on line w celu zapobieżenia rozprzestrzeniania się zakłóceń i awarii w systemach elektroenergetycznych.
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Modelling EMI choke for the power electronics application
PublicationPrzedstawiono wyniki przeprowadzonych badań symulacyjnych i eksperymentalnych dotyczących propagacji zakłóceń elektromagnetycznych przewodzonych w dławikach przeciwzakłóceniowych stosowanych w przekształtnikach energoelektronicznych. Zaproponowany model obwodowy dławika pozwala na analizę symulacyjną właściwości w zakresie częstotliwości zaburzeń elektromagnetycznych przewodzonych. Model uwzględnia zjawiska związane z pojemnościami...
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Environmental safety of a seagoing ship power plant.
PublicationPrzedstawiono probabilistyczne podejście do oceny bezpieczeństwa środowiskowego siłowni statku. Zaproponowano kryterium oceny bezpieczeństwa środowiskowego siłowni statku.
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On energy, exergy, and environmental aspects of a combined gas-steam cycle for heat and power generation undergoing a process of retrofitting by steam injection
PublicationThe paper presents a study of retrofitting of a combined heat and power (CHP) plant aimed to increase the electric to heating power ratio. The modification would involve diverting part of the steam to the gas turbine, instead of letting it go to the steam turbine, using injection technique into a combustion chamber. Therefore, two potential retrofitting approaches are analyzed: steam injection gas turbine (STIGT) and combined steam...
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WSPÓŁPRACA BLOKU GAZOWO-PAROWEGO Z OBIEGIEM ORC = Combinded power plant in cooperation with ORC
PublicationIn the paper presented is the idea of a combined gas and steam power plant cooperation with a low temperature organic Rankine cycle ORC unit. Considerations presented in the paper are accomplished for the Gorzów CHP. The intention of present analysis is heat recovery of low temperature energy and its further use in ORC cycle in order to produce electricity, without increase in fuel consumption. Waste energy is recovered from the...
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The Ellenbogen's "Matter as Software" Concept for Quantum Computer Implementation: III. Selection of X@C60 Molecular Building Blocks (MBBs) for Tip-Based Nanofabrication (TBN) of Trapped Neutral Atom Quantum Computing Devices
PublicationThe selection of guest atoms X of X@C60 MBBs for TBN of trapped neutral atom quantum computing devices is reported. Assuming the all-optical quantum computing as a final target stage, the two criteria are most important: the charge q accumulated on the C60 host must be as low as possible, and the atom X must have one or more available excited states within the band falling into the low energy window of neutral C60 molecule electronic...
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Specificity of automatic control of micro-turbines (steam or gas -driven and expanders) in dispersed generation system of heat and electric power
PublicationThis paper presents specific problems of automatic control of steam micro-turbines and expanders intended for the dispersed, combined generating of heat and electric power. The investigations concern ensurance of certainty of energy supply and its required quality.
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The Impact of Direct Normal Irradiation on the Solar Tower Power Plant Performance based on Real and Satellite Data: Analysis on Algerian Regions
PublicationThe present paper presents a deep study on the possibility of implementing Concentrated Solar Power (CSP) plants in Algeria for the production of the electrical energy. Indeed, this paper focusses mainly on the main parameters, which can have an important impact on the choice of the location, the dimension and the available thermal energy storage system. In this study, three main parameters are investigate...
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Elimination of the negative effect of earth fault current higher frequency on tripping of residual current devices
PublicationCzęstotliwość prądu różnicowego większa niż 50/60 Hz ma niekorzystny wpływ na wyzwalanie wyłączników różnicowoprądowych. Przy zwiększonej częstotliwości prądu różnicowego rzeczywisty prąd zadziałania wyłączników zwiększa się, a niektóre z nich w ogóle nie wyzwalają. W artykule omówiono główne przyczyny zwiększenia się prądu zadziałania wyłączników różnicowoprądowych oraz przedstawiono sposób eliminacji niekorzystnego wpływu zwiększonej...
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Residual Current Devices Operational Characteristics within the Frequency Range 50 Hz to 1000 Hz.
PublicationW artykule przedstawiono charakterystyki działania powszechnie stosowanych wyłączników różnicowoprądowych przy prądach różnicowych w zakresie częstotliwości 50÷1000 Hz. Częstotliwość wyższa niż 50 Hz wpływa niekorzystnie na prąd zadziałania wyłączników, a w skrajnych przypadkach mogą one w ogóle nie reagować na wolno narastający prąd różnicowy.
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Modified monopole ring antennas as a solution for HiperLAN1/2 and IEEE 802.11b/g standard devices
PublicationZaprojektowano, wykonano i przebadano pierścieniową antenę planarną przeznaczona do aplikacji multisystemowych. Zastosowano system zasilania poprzez linie mikropaskową oraz dobrano wymiary i kształty pierścieni (promienników) w taki sposób, aby odpowiednio ''ulokować'' podzakresy pracy anteny. Zrealizowany prototyp anteny pracuje w zakresie standardów IEEE 802.11b/g oraz HiperLAN1/2.
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Optoelectronic Devices, Sensors, Communication and Multimedia, Photonics Applications and Web Engineering, Wilga, May 2012
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The effect of PWM frequency on the effectiveness of protection against electric shock using residual current devices
PublicationW artykule przedstawiono analizę widmową odkształconego prądu ziemnozwarciowego z obwodu silnika o regulowanej prędkości obrotowej za pomocą przemiennika częstotliwości. Oceniono skuteczność ochrony przeciwporażeniowej wykorzystującej wyłączniki różnicowoprądowe przy różnych wartościach częstotliwości PWM przemiennika. Przedstawiono charakterystykę działania proponowanego wyłącznika różnicowoprądowego.
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The effect of PWM frequency on the effectiveness of protection against electric shock using residual current devices
PublicationW referacie przedstawiono analizę widmową odkształconego prądu ziemnozwarciowego z obwodu silnika o regulowanej prędkości obrotowej za pomocą przemiennika częstotliwości. Oszacowano wpływ tego odkształcenia na próg fibrylacji serca. Analizowano skuteczność ochrony przeciwporażeniowej wykorzystującej wyłączniki różnicowoprądowe przy różnych wartościach częstotliwości PWM przemiennika. Przedstawiono charakterystykę działania zaproponowanego...
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A universal IT system architecture for servicing, collecting, storing, processing and presenting data from wireless devices
PublicationIn the article we present a universal IT system architecture, which allows one to develop, based on mobile and multiplatform JAVA language, applications capable of working with many different wireless systems in an easy and effective way. Modular system architecture supports efficient data processing and enables convenient presentation of chosen parameters. Additionally, proposed IT system architecture provides easy adoption to...
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Fluctuation-Enhanced Sensing of Organic Vapors by Ink-Printed MoS2 Devices under UV Irradiation
PublicationThis work presents the results of fluctuationenhanced sensing (FES) of selected organic gases by MoS2 sensor fabricated via a simple ink printing method. We demonstrate that low-frequency noise measured under UV irradiation (275 nm) is more sensitive to different gases than measured in the dark. The noise at 1 Hz under UV light increased 3.3, 3.5, 1.6, and 2.9 times for chloroform, tetrahydrofuran, acetonitrile, and acetone ambiances, respectively....
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Design of a test bench for determining the general characteristics of an internal combustion engine using a hydraulic power take-off system
PublicationThe paper presents a design of an engine test bench, which is used to determine the general characteristics of a truck engine using a power take-off (PTO). PTO drives a hydraulic system that generates a load on the engine at various points in its operation in the power range specified by the hydraulic system. The design allows for stationary and mobile tests with the test bench mounted on the truck, without any modification of...
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The Finite Elements Method application to assesment the impact of turbulence generated by wind turbines on their lacation inclose proximity of overhead high voltage power transmissionlines
PublicationThe paper presents selected aspects of construction of wind turbines location concerning aerodynamic impact on power lines. Reaserch is based on the source data concerning the aerodynamic impact of a wind farm consisting of 8 turbines and 400 kV power line, an analysis of the possibility of wind farm locating in the immediate vicinity of the line was carried out. There are serious problems with locating higher capacity wind farms...
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Size and mass minimization of capacitor bank in a power converter DC line of DC drive with closed loop control system with PWM and current limitation
PublicationPaper deals with evaluation equations for power filter of AC-DC power converter which allows to provide size and mass minimization of capacitor bank in DC drive closed loop systems with PWM and current limitation. Reliability of provided equations is proved by simulation in MATLAB/Simulink
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Low-Power Receivers for Wireless Capacitive Coupling Transmission in 3-D-Integrated Massively Parallel CMOS Imager
PublicationThe paper presents pixel receivers for massively parallel transmission of video signal between capacitive coupled integrated circuits (ICs). The receivers meet the key requirements for massively parallel transmission, namely low-power consumption below a single μW, small area of less than 205 μm2, high sensitivity better than 160 mV, and good immunity to crosstalk. The receivers were implemented and measured in a 3-D IC (two face-to-face...
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Adaptive Algorithm of a Tap-Changer Controller of the Power Transformer Supplying the Radial Network Reducing the Risk of Voltage Collapse
Publicationhe development of renewable energy, including wind farms, photovoltaic farms as well as prosumer installations, and the development of electromobility pose new challenges for network operators. The results of these changes are, among others, the change of network load profiles and load flows determining greater volatility of voltages. Most of the proposed solutions do not assume a change of the transformer regulator algorithm....
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Direct-contact condensation from vapour- gas mixture in a spray ejector condenser for negative CO2 power plant
PublicationDirect-contact condensation of vapour containing the inert gas on a spray of subcooled liquid exists in a number of technical applications. For example, it may be found in the nuclear industry (e.g. pressurized jet under normal operating conditions, in safety analyses) or in the chemical industry (e.g. mixing-type heat exchanger, degasser, sea water desalting). The problem is also essential to modelling and analysis of some...
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Light-Powered Starter for Micro-Power Boost DC–DC Converter for CMOS Image Sensors
PublicationThe design of a starter for a low-voltage, micro-power boost DC–DC converter intended for powering CMOS image sensors is presented. A unique feature of the starter is extremely low current, below 1 nA, supplying its control circuit. Therefore, a high-voltage (1.3 V) configuration of series-connected photovoltaic diodes available in a standard CMOS process or a small external LED working in photovoltaic mode can be used as an auxiliary...
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The Method of Multi-criteria Analysis to Support the Decision on Load or Micro-generation Connection to a Low- or Medium-voltage Power Grid
PublicationThis paper presents a method that supports the decision in terms on selecting the best option of a load connection to a low- or medium-voltage power distribution grid, and of a micro-generation source connection to a low-voltage grid. The method is based on the search for the option with the lowest aggregate assessment measure, which is the weighted average of partial assessment measures determined for each of eight considered...
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Comparison of the powers of energy losses in a variable capacity displacement pump determined without or with taking into account the power of hydraulic oil compression
PublicationPowers of energy losses in a variable capacity displacement pump are compared with or without taking into account the power of hydraulic oil compression. Evaluation of power of liquid compression in the pump was made possible by the use of method, proposed by the Author, of determining the degree of liquid aeration in the pump. In the method of determining the liquid aeration in the pump and of powers of volumetric losses of liquid...
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Electrical Tree Growth Behavior Under AC and DC High Voltage in Power Cables
PublicationThis work investigates the impact of an applied AC and DC high voltage on the electrical tree behavior in extruded cross-linked polyethylene (XLPE) insulation based on simulation and experimental validation. Extensive partial discharge (PD) testing methods are being implemented for high voltage cables under AC voltage for monitoring their condition. However, these PD testing methods cannot be utilized for power cables under DC...
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Accurate electrothermal modelling of high frequency DC-DC converters with discrete IGBTs in PLECS software
PublicationIn the paper, a novel, improved method of the IGBT junction temperature computations in the PLECS simulation software is presented. The developed method aims at accuracy of the junction temperature computations in PLECS by utilising a more sophisticated model of transistor losses, and by taking into account variability of transistor thermal resistance as a function of its temperature. A detailed description of the proposed method,...
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Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
PublicationThe study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon...
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Exergy analysis of a negative CO2 emission gas power plant based on water oxy-combustion of syngas from sewage sludge gasification and CCS
PublicationA power cycle with water-injected oxy-combustion (water cycle) is investigated by exergy analysis. It is fueled with syngas (aka. producer gas) from gasification of sewage sludge. The cycle is equipped with a spray-ejector condenser (SEC). CO2 is separated and compressed for transportation and storage. The net delivered electric power is 31% of the fuel exergy. The task efficiency is 39% when the flue gas bleed to gasification...
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Hydrostatic drives as safe and energy saving machines. The drive investigation method compatible diagram of power increase opposite to the direction of power flow
PublicationProjektanci i producenci napędu hydrostatycznego nie dysponują możliwością dokładnego określania jego sprawności energetycznej zmieniającej się szeroko w polu pracy napędzanego urządzenia a więc w pełnym zakresie zmiany prędkości i obciążenia silnika hydraulicznego oraz lepkości zastosowanego czynnika roboczego. Dotyczy to zarówno określania strat i sprawności maszyn wyporowych (pompy i silnika hydraulicznego) zastosowanych w układzie...
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Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 1/2
PublicationWind power plants are considered as ecologically-clean source of energy. However, manufacturing processes cannot be treated that way. Manufacturing processes consume huge amount of electrical and thermal energy and significant amount of materials, e.g. steel, polymers, oils and lubricants. All of the above could be potentially harmful for environment. There are not many works and publications regarding life-cycle analysis of wind...
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Maximum Power Point Technique (MPPT) for PV System Based on Improved Pert and Observe (P&O) Method with PI Controller
PublicationPhotovoltaic power generation system has key rule in electricity production. Although, it is clean renewable energy with unlimited resources but it has some drawbacks in efficiency. In order to maximize the efficiency, PV array must drive at maximum power point. For the reason so, several algorithms are used in PV system to track MPP and reduce the...
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Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
PublicationThe short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The...
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Design of a simple modular active power electronic transformer
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