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Search results for: electronics
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Influence of Self-Similar Traffic Type on Performance of QoS Routing Algorithms
PublicationProviding a Quality of Services (QoS) into current telecommunication networks based on packet technology is a big challenge nowadays. Network operators have to support a number of new services like voice or video which generate new type of traffic. This traffic serviced with QoS in consequence requires access to appropriate network resources. Additionally, new traffic type is mixed with older one, like best-effort. Analysis of...
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Optical Theorem Helps Understand Thresholds of Lasing in Microcavities With Active Regions
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AM Modulation Signal Estimation Allowing Further Research on Sources of Voltage Fluctuations
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Dual-Frequency Induction Heating Generator With Adjustable Impedance Matching
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Advanced Photonic and Electronic Systems WILGA 2017
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Enhanced European Coordination of Accelerator Research and Development – EuCARD2 – Global and Local Impact
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Advanced photonic and electronic systems WILGA 2016
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ARIES – Development of Accelerator Technology in Europe 2017-2020: Global and Local Consequences
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CBM Experiment Local and Global Implications
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Development of Free Electron Lasers in Europe Local and Global Implications – 2016
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AP-MOVPE Technology and Characterization of InGaAsN p-i-n Subcell for InGaAsN/GaAs Tandem Solar Cell
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International Linear Collider Global and Local Implications
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International Linear Collider Global and Local Implications
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Electronic and Photonic Systems Wilga 2014
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LCLS – Large Laser Infrastructure Development and Local Implications
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LCLS – Large Laser Infrastructure Development and Local Implications
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IYL 2015 in Poland
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Electronic and Photonic Systems Wilga 2014
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Comparison of Impedance-Source Networks for Two and Multilevel Buck–Boost Inverter Applications
Publicationmpedance-source networks are an increasingly popular solution in power converter applications, especially in single-stage buck-boost power conversion to avoid additional front-end dc-dc power converters. In the survey papers published, no analytical comparisons of different topologies have been described, which makes it difficult to choose the best option. Thus, the aim of this paper is to present a comprehensive analytical comparison...
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Novel Family of Single-Phase Modified Impedance-Source Buck-Boost Multilevel Inverters With Reduced Switch Count
Publicationhis paper describes novel single-phase solutions with increased inverter voltage levels derived by means of a nonstandard inverter configuration and impedance source networks. Operation principles based on special modulation techniques are presented. Detailed component design guidelines along with simulation and experimental verification are also provided. Possible application fields are discussed, as well as advantages and disadvantages....
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Multi-transformer primary-side regulated flyback converter for supplying isolated IGBT and MOSFET drivers
PublicationThis paper presents primary-side voltage regulated multi-transformer quasi-resonant flyback converter (MTFC) for supplying isolated power switch drivers. The proposed topology offers distinct advantages over frequently used flyback converter possessing one high frequency transformer with isolated multiple outputs. Particularly, when a large number of separate dc supply units is required, then MTFC enables improved regular distribution...
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An Empirical Propagation Model for Corridors in Office Buildings
PublicationThis paper presents an empirical propagation path loss model for corridors in office buildings. The proposed model estimates changeable character of radio signal attenuation, based on a special approach as a combination of the simple free-space model with the author’s model. The measurement stand and measurement scenario are described. The propagation path loss research have been made in corridor for different frequencies in range...
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Errors of a Linear Current Approximation in High-Speed PMSM Drives
PublicationCurrent sampling techniques and predictive algorithms used in the digital control of electric drives rely on a simple mathematical model that assumes linear current changes upon constant supplying voltages. This paper identifies rotor movement as a factor that makes this assumption invalid when the rotor covers an angular distance of a few tens of degrees during the control interval duration. The errors of the linear current approximation...
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Open-transistor fault diagnostics in voltage-source inverters by analyzing the load current
PublicationPrzedstawiono nową metodę detekcji i lokalizacji uszkodzeń polegających na braku przewodzenia tranzystorów w falownikach napięcia zasilających silniki indukcyjne. Metoda jest rozszerzeniem, opracowanej wcześniej, metody wykorzystującej znormalizowane składowe stałe prądów obciążenia. Znormalizowane wartości średnie prądów powiązano z dodatkowymi wskaźnikami diagnostycznymi, które zawierają informacje o czasie trwania nieprzewodzenia...
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Advanced control of induction motor based on load angle estimation.
PublicationW artykule przedstawiono układ sterowania silnikiem asynchronicznym klatkowy wykorzystujący estymację kąta obciążenia pracujący bez pomiaru prędkości obrotowej. W artykule przedstawiono zasadę działania układu i motodę odtwarzania zmiennych opartą w części o zależności stanu ustalonego. Przedstawiono zrealizowany regulator rozmyty kąta obciążenia. Zaprezentowane zostały wyniki symulacji i eksperymentu przeprowadzone z użyciem...
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Reducing common mode voltage and bearing currents in quasi - resonant DC - link inverter
PublicationIn the paper, a concept of separation of an inverter-fed induction motor drive from its mains supply by two transistor switches inserted in the dc-link circuit is reexamined based on the proposed parallel quasi-resonant dc-link inverter (PQRDCLI). The objective of the paper is to show an advantage of the proposed topology in limiting high frequency common mode voltage and bearing currents. In the laboratory setup, an induction...
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Application of sliding switching functions in backstepping based speed observer of induction machine
PublicationThe paper presents an analysis of the speed observer which is based on the backstepping and sliding mode approach. The speed observer structure is based on the extended mathematical model of an induction machine. The observer structure is based on the measured phase stator currents and transformed to ( αβ ) coordinate system. The stator voltage vector components are treated as known values. Additionally, such an observer structure...
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Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublicationThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
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Feedback Control of Multiphase Induction Machines with Backstepping Technique
PublicationThe paper presents the control possibility of five phase induction machines. In the proposed solution the machine model vector form is not transformed to the (dq)-coordinate system, that is connected to rotor flux vector, but utilizes the stationary system ( αβ ). Moreover, the nonlinear model linearization is based on demonstrated nonlinear variables transformation for i-orthogonal ( αβ )(n) planes. By introducing the backstepping...
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AEGIS – Mobile Device for Generating Electromagnetic Curtain for Special Applications and Countering the Threats of RCIED
PublicationIn the article the assumptions, design and realization of the technological demonstrator of a mobile device for generating an electromagnetic curtain (with a cryptonym AEGIS) were presented, both in the area of hardware and software. The device is designed to block the radio communication systems by which it is possible to detonate the Radio Controlled Improvised Explosive Devices (RCIEDs). The preliminary laboratory tests of the...
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Application of Analytic Signal and Smooth Interpolation in Pulse Width Modulation for Conventional Matrix Converters
PublicationThe paper proposes an alternative and novel approach to the PWM duty cycles computation for Conventional Matrix Converters (CMC) fed by balanced, unbalanced or non–sinusoidal AC voltage sources. The presented solution simplifies the prototyping of direct modulation algorithms. PWM duty cycles are calculated faster by the smooth interpolation technique, using only vector coordinates, without trigonometric functions and angles. Both...
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General Description of State-Space Continuous-Time Gm-C Filters
PublicationW pracy przedstawiono ogólne podejście do analogowych filtrów Gm-C czasuciągłego, oparte o opis macierzowy. Przedstawiono związki pomiędzy sieciąpasywną filtru a funkcją przenoszenia. Podano nową definicję filtrów zmien-nych stanu Gm-C oraz opisano dwie interesujące podklasy filtrów Gm-C jakrównież podano kanoniczne transformacje przekształcające struktury z pojem-nościami nieuziemionymi w struktury zawierające wyłącznie...
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Efficient tolerance analysis of continuous-time Gm-C filters
PublicationW pracy przedstawiono efektywną metodą analizy tolerancji dowolnych filtrów Gm-C. Przedstawiono ogólny model filtrów Gm-C oraz jego opis algebraiczny. Używając tego podejścia, wyprowadzono formuły pozwalające na wyznaczenie odchyłek funkcji przenoszenia filtru spowodowanych odchyłkami wartości elementów filtru od wartości nominalnych. Proponowana metoda charakteryzuje się niewielką złożonością obliczeniową, co pozwala na jej wykorzystanie...
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A Microwave Sensor with Operating Band Selection to Detect Rotation and Proximity in the Rapid Prototyping Industry
PublicationThis paper presents a novel sensor for detecting and measuring angular rotation and proximity, intended for rapid prototyping machines. The sensor is based on a complementary split-ring resonator (CSRR) driven by a conductor-backed coplanar waveguide. The sensor has a planar topology, which makes it simple and cost-effective to produce and accurate in measuring both physical quantities. The sensor has two components, a rotor, and...
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A reactive algorithm for deducing nodal forwarding behavior in a multihop ad-hoc wireless network in the presence of errors
PublicationA novel algorithm is presented to deduce individual nodal forwarding behavior from standard end-to-end acknowledgments. The algorithm is based on a well-established mathematical method and is robust to network related errors and nodal behavior changes. The proposed solution was verified in a network simulation, during which it achieved sound results in a challenging multihop ad-hoc network environment.
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Rotor-Flux Vector based Observer of Interior Permanent Synchronous Machine
PublicationThe sensorless control system of the interior permanent magnet machine is considered in this paper. The control system is based on classical linear controllers. In the machine, there occurs non-sinusoidal distribution of rotor flux together with the slot harmonics, which are treated as the control system disturbances. In this case, the classical observer structure in the (d-q) is unstable for the low range of rotor speed resulting...
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Battery Technologies in Electric Vehicles: Improvements in Electric Battery Packs
PublicationRestrictions on fossil fuels and related environmental pollution issues motivate many organizations and countries to set their focus on electric vehicles (EVs) rather than conventional internal combustion engine vehicles [1], [2]. EVs require an energy storage system to store converted electric power in another form of energy and then reconvert the stored energy to electric power whenever it is required. The energy stored can be...
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Feedback Control of Doubly-Fed Generator Connected to Current Source Converter
PublicationDoubly-fed induction generator (DFIG) system supplied by current source converter (CSC) is considered in this article. The DFIG can work in two independent modes: AC grid connection and stand-alone mode. The DFIG is connected to the ac grid directly through its stator and the CSC links the rotor side. In this mode, the active and reactive powers of the DFIG must be controlled. This article proposes two control system structures...
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Hybridized PWM Strategy for Three- and Multiphase Three-Level NPC Inverters
PublicationA simple hybridized pulsewidth modulation (PWM) algorithm for three- and multiphase three-level neutral point clamped (NPC) inverters is proposed. The proposed solution is based on classical space vector PWM (SVPWM) algorithms for two-level inverters but can also be based on sinusoidal PWM with min–max injection. An additional level of output voltage is obtained by modifying the resulting switching patterns taking into account...
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AC Microgrid Control and Management Strategies: Evaluation and Review
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Half-Order Modeling of Saturated Synchronous Machine
PublicationNoninteger order systems are used to model diffusion in conductive parts of electrical machines as they lead to more compact and knowledge models but also to improve their precision. In this paper a linear half-order impedance model of a ferromagnetic sheet deduced from the diffusion of magnetic field is briefly introduced. Then, from physical considerations and finite elements simulation, the nonlinear half-order impedance model...
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Speed and load torque observer application in high-speed train electric drive
PublicationW artykule przedstawiono zastosowanie diagnostyczne obserwatorów prędkości obrotowej i momentu obciążenia w układzie napędowym z silnikiem asynchronicznym. System diagnostyczny jest dedykowany do napędu pociągu szybkiego. Celem diagnostycznym jest monitorowanie stanu czujnika prędkości obrotowej wału silnika oraz układu przeniesienia momentu trakcyjnego. Analiza sygnałów obliczanych w obserwatorach stanu pozwala na wykrycie uszkodzeń...
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Performance Evaluation of Preemption Algorithms in MPLS Networks
PublicationPreemption is a traffic engineering technique in Multiprotocol Switching Networks that enables creation of high priority paths when there is not enough free bandwidth left on the route. Challenging part of any preemption method is to select the best set of paths for removal. Several heuristic methods are available but no wider comparison had been published before. In this paper, we discuss the dilemmas in implementing preemption...
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Interactive Query Expansion with the Use of Clustering by Directions Algorithm
PublicationThis paper concerns Clustering by Directions algorithm. The algorithm introduces a novel approach to interactive query expansion. It is designed to support users of search engines in forming web search queries. When a user executes a query, the algorithm shows potential directions in which the search can be continued. This paper describes the algorithm and it presents an enhancement which reduces the computational complexity of...
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Quasi-resonant dc-link inverter with a reduced number of active elements
PublicationW artykule przedstawiono nową topologię równoległego quasi-rezonansowego obwodu pośredniczącego falownika napięcia. Opisano sekwencje miękkiej komutacji falownika w dwukierunkowym trybie pracy falowniczej i prostowniczej. Analiza układu została zweryfikowana badaniami symulacyjnymi i eksperymentalnymi. Przedstawiona topologia odznacza się prostą strukturą oraz małą ilością elementów aktywnych. Dzięki zastosowaniu krzepkiej strategii...
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Comments on unified analysis of switched-capacitor resonant converters
PublicationW pracy przedyskutowano możliwości regulacji napięcia wyjściowego w powielaczu typu c-przełączane, wpływ na sprawność energetyczną, użycie dodatkowych induktorów.
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An overview of Multiple-Input Multiple-Output(MIMO) system
PublicationW artykule omówiono podstawy teoretyczne funkcjonowania systemów wieloantenowych, w tym korzyści wynikające z ich stosowania, podstawowe konfiguracje systemów wieloantenowych i opis ich działania, pojęcie pojemności kanału MIMO i jego modelowania oraz dwa podstawowe sposoby realizacji techniki MIMO, tj. kodowanie przestrzenno-czasowe i multipleksacja przestrzenna (techniki BLAST).
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New methods for location service in the WCDMA system
PublicationOpracowano dwie nowe metody lokalizowana terminala ruchomego w sieciach komórkowych opartych o szerokopasmowy interfejs radiowy WCDMA. Przedstawiono szczegółowy ich opis działania. Zaprezentowano model symulacyjny oraz wyniki badań symulacyjnych przydatności opracowanych metod dla potrzeb europejskiego systemu bezpieczeństwa E112.
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Radio wave propagation conditions for terrestrial radiocommunications in the EHF band
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A nearly optimal fractional delay filter design with asymmetric window
PublicationW pracy przedstawiono wyniki badań nad zastosowaniem asymetrycznego okna wyodrębnionego zawczasu z filtru optymalnego. Pokazano, że takie podejście przy zastosowaniu dodatkowej korekcji wzmocnienia filtru zależnej od opóźnienia filtru pozwala na projektowanie filtrów prawie optymalnych. W efekcie zaproponowana metoda łączy prostotę metody okien z jakością porównywalną do jakości filtrów optymalnych. Efektywność zaprezentowanej...