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Search results for: IEEE 802151
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Triangulation-based Constrained Surrogate Modeling of Antennas
PublicationDesign of contemporary antenna structures is heavily based on full-wave electromagnetic (EM) simulation tools. They provide accuracy but are CPU-intensive. Reduction of EM-driven design procedure cost can be achieved by using fast replacement models (surrogates). Unfortunately, standard modeling techniques are unable to ensure sufficient predictive power for real-world antenna structures (multiple parameters, wide parameter ranges,...
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Chosen Analysis Results Of The Prototype Multicell Piezoelectric Motor
PublicationThis paper presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a “single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
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On Alternative Approaches to Design of Corporate Feeds for Low-Sidelobe Microstrip Linear Arrays
PublicationTwo design approaches, illustrated by simulations and measurements, aiming at a systematic computer-aided design of printed circuit feeds for low-sidelobe microstrip antenna arrays are described. The novelty of these approaches resides in identification of the optimal feed architectures with subsequent simulation-based optimization of the feed and array aperture dimensions. In this work, we consider microstrip corporate feeds realizing...
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Fading Modeling in Maritime Container Terminal Environments
PublicationIn this paper, an analytical model for slow and fast fading effects in maritime container terminals is derived, from fitting distributions to the results of measurements performed in an actual operational environment. The proposed model is composed of a set of equations, enabling to evaluate fading statistical distribution parameters for different system and environments conditions, as a function of frequency, base station antenna...
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A High-Efficient Measurement System With Optimization Feature for Prototype CMOS Image Sensors
PublicationIn this paper, a gray-scale CMOS image sensor (CIS) characterization system with an optimization feature has been proposed. By using a very fast and precise control of light intensity, based on the pulsewidth-modulation method, it is avoided to measure the illuminance every time. These features accelerate the multicriteria CIS optimization requiring many thousands of measurements. The system throughput is 2.5 Gb/s, which allows...
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Global Complex Roots and Poles Finding Algorithm Based on Phase Analysis for Propagation and Radiation Problems
PublicationA flexible and effective algorithm for complex roots and poles finding is presented. A wide class of analytic functions can be analyzed, and any arbitrarily shaped search region can be considered. The method is very simple and intuitive. It is based on sampling a function at the nodes of a regular mesh, and on the analysis of the function phase. As a result, a set of candidate regions is created and then the roots/poles are verified...
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Combined Single Neuron Unit Activity and Local Field Potential Oscillations in a Human Visual Recognition Memory Task
PublicationGOAL: Activities of neuronal networks range from action potential firing of individual neurons, coordinated oscillations of local neuronal assemblies, and distributed neural populations. Here, we describe recordings using hybrid electrodes, containing both micro- and clinical macroelectrodes, to simultaneously sample both large-scale network oscillations and single neuron spiking activity in the medial temporal lobe structures...
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Secure Quaternion Feistel Cipher for DICOM Images
PublicationAn improved and extended version of a quaternion-based lossless encryption technique for digital image and communication on medicine (DICOM) images is proposed. We highlight and address several security flaws present in the previous version of the algorithm originally proposed by Dzwonkowski et al. (2015). The newly proposed secure quater- nion Feistel cipher (S-QFC) algorithm...
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Performance-Based Nested Surrogate Modeling of Antenna Input Characteristics
PublicationUtilization of electromagnetic (EM) simulation tools is mandatory in the design of contemporary antenna structures. At the same time, conducting designs procedures that require multiple evaluations of the antenna at hand, such as parametric optimization or yield-driven design, is hindered by a high cost of accurate EM analysis. To certain extent, this issue can be addressed by utilization of fast replacement models (also referred...
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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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Amplifying the Randomness of Weak Sources Correlated With Devices
PublicationThe problem of device-independent randomness amplification against no-signaling adversaries has so far been studied under the assumption that the weak source of randomness is uncorrelated with the (quantum) devices used in the amplification procedure. In this paper, we relax this assumption, and reconsider the original protocol of Colbeck and Renner using a Santha-Vazirani (SV) source. To do so, we introduce an SV-like condition...
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Comprehensive comparison of compact UWB antenna performance by means of multi-objective optimization
PublicationAn optimization-based procedure for comprehensive performance comparison of alternative compact UWB antenna topologies is discussed. The assessment of the antenna performance is conducted with respect to the structure size and its reflection response. More specifically, the best possible tradeoffs between these two figures of merit are identified through multiobjective optimization at the level...
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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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Simplified Approach for Broadband RF Testing of Low Loss Magneto-Dielectric Samples
PublicationIn this paper, an attractive measurement techniqueis proposed to retrieve the broadband permittivity and permeabil-ity of the magneto-dielectric materials. The proposed techniqueis quite novel which mitigates the major problems associatedwith the conventional broadband RF material characterizationtechniques such as numerical instability and phase uncertaintywhen the length of the sample exceeds...
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Accurate Computation of IGBT Junction Temperature in PLECS
PublicationIn the article, a new method to improve the accuracy of the insulated-gate bipolar transistor (IGBT) junction temperature computations in the piecewise linear electrical circuit simulation (PLECS) software is proposed and described in detail. This method allows computing the IGBT junction temperature using a nonlinear compact thermal model of this device in PLECS. In the method, a nonlinear compact thermal model of the IGBT is...
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Lagrangian model of an isolated dc-dc converter with a 3-phase medium frequency transformer accounting magnetic cross saturation
PublicationThis article presents a nonlinear equivalent circuit model of an isolated dc-dc converter with a 3-phase medium frequency transformer. The model takes into account the magnetic cross saturation of the 3-phase core-type magnetic circuit. The model is suitable in detailed electromagnetic transient simulations of power systems involving isolated dc-dc converters. The model is developed using the Lagrange energy method. It involves...
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Speed Observer Structure of Induction Machine Based on Sliding Super-Twisting and Backstepping Techniques
PublicationThis paper presents an analysis of the two speed observer structures which are based on the backstepping and sliding super twisting approach. The observer stabilizing functions result from the Lyapunov theorem. To obtain the observer tuning gains the observer structure is linearized near the equilibrium point. The rotor angular speed is obtained from non-adaptive dependence. In the sensorless control system structure the classical...
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Could thermal imaging supplement surface electromyography measurements for skeletal muscles?
PublicationAbstract—(1) Background: The aim of this study is to present the results of experiments in which surface electromyography (sEMG) and thermal imaging were used to assess muscle activation during gait and to verify the hypothesis that there is a relationship in the case of low fatigue level between sEMG measured muscle activation, assessed in the frequency domain, and thermal factors calculated as minimum, maximum, kurtosis, mean,...
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Novel Coplanar-Strip-Based Excitation Technique for Design of Broadband Circularly Polarization Antennas with Wide 3-dB Axial Ratio Beamwidth
PublicationIn this paper, a novel excitation technique for design of a single-point-fed compact low-profile wide-slot antennas with broadband circular polarization (CP) and wide 3 dB axial ratio (AR) beamwidth is presented. Two inverted L-shape parasitic strips placed coplanar to the microstrip line of an asymmetric CPW, and a horizontal strip that protrudes from the vertical edge of the backside ground plane of the substrate are used for...
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Seafloor Characterisation Using Underwater Acoustic Devices
PublicationThe problem of seafloor characterisation is important in the context of management as well as investigation and protection of the marine environment. In the first part of the paper, a review of underwater acoustic technology and methodology used in seafloor characterisation is presented. It consists of the techniques based on the use of singlebeam echosounders and seismic sources, along with those developed for the use of sidescan...
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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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On Noncausal Identification of Nonstationary Multivariate Autoregressive Processes
PublicationThe problem of identification of nonstationary multivariate autoregressive processes using noncausal local estimation schemes is considered and a new approach to joint selection of the model order and the estimation bandwidth is proposed. The new selection rule, based on evaluation of pseudoprediction errors, is compared with the previously proposed one, based on the modified Akaike’s final prediction error criterion.
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Lattice filter based multivariate autoregressive spectral estimation with joint model order and estimation bandwidth adaptation
PublicationThe problem of parametric, autoregressive model based estimation of a time-varying spectral density function of a multivariate nonstationary process is considered. It is shown that estimation results can be considerably improved if identification of the autoregressive model is carried out using the two-sided doubly exponentially weighted lattice algorithm which combines results yielded by two one-sided lattice algorithms running...
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Step-Up DC/DC Converters With Cascaded Quasi-Z-Source Network
PublicationW artykule zaprezentowano nowe rozwiązania dotyczące przekształtników energoelektronicznych DC-DC podwyższających napięcie z ogniw paliwowych. Istota rozwiązania zawiera się w zastosowaniu kaskadowo połączonych wejściowych obwodów pasywnych typu Quasi-Z, umozliwiających znaczne podwyższanie napięcia z wykorzystaniem stanu parcy zwarć gałęzi tranzystorowych przekształtnika.
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The Adaptive Backstepping Control of Permanent Magnet Synchronous Motor Supplied by Current Source Inverter
Publication...
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Accuracy of the Discrete Green's Function Formulation of the FDTD Method
PublicationThis paper reports an evaluation of the accuracy of the discrete Greens function (DGF) formulation of the finite-difference time-domain (FDTD) method. Recently, the closed-form expression for the DGF and its efficient numerical implementation were presented, which facilitates applications of the DGF in FDTD simulations of radiation and scattering problems. So far, the accuracy of the DGF formulation of the FDTD method has been...
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A New Coupler Concept for Contactless High-Speed Data Transmission Monitoring
PublicationThis paper presents a new concept of a couplerthat can be applied to high-speed data transmission contactlessmeasurements. The proposed approach is dedicated for differentialsignal transmission monitoring in microstrip coupled lineson printed circuit boards (PCBs). The coupler, produced on aseparate PCB, is overlayed on the transmission line with thedifferential signal and delivers decoupled differential signal tothe main measurement...
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Comments on “Closed Form Variable Fractional Time Delay Using FFT”
PublicationIn this letter drawbacks of the aforementioned paper are pointed out. The proposed approach is improved with minor modifications of the discrete frequency response. This allows for design of fractional delay filters which are close to optimal and can be efficiently implemented in the frequency domain using the sliding DFT based structure. Alternatively, the derived equivalent closed form formulae for offset windows can be used...
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Fast Re-Design of Multi-Band Antennas by Means of Orthogonal-Direction Geometry Scaling and Local Parameter Tuning
PublicationApplication-driven design of antenna systems fosters a reuse of structures that have proven competitive in terms of their electrical and field performance, yet have to be re-designed for a new application area. In practice, it most often entails relocation of the operating frequencies or bandwidths, which is an intricate endeavor, normally requiring utilization of numerical optimization techniques. If the center frequencies of...
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Electrical Simulations of the SIS100 Superconducting Dipole and Quadrupole Circuits: Transients, Earthing and Failure Modes
PublicationThe 100 Tm superconducting synchrotron SIS100 is the main accelerator of the international Facility for Antiproton and Ion Research (FAIR) currently under advanced construction in Darmstadt, Germany. The SIS100 dipole circuit which creates the magnetic field required to bend the beam, consists of 108 dipoles distributed over six arc sections of the ring. The magnetic field for the beam focusing is generated by three individual...
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Heat Dissipation from the Power Cable in the Casing Pipe
PublicationThe current carrying capacity of a power cable determines its ability to carry a specific current and is related to the efficiency of dissipation of heat generated in the cable laid in a specific environment. The studies were conducted in order to determine how the characteristics of the medium around the cable affected its temperature, and thus the ability of the cable to transmit electricity. The experimentation in the lab and...
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On optimal tracking of rapidly varying telecommunication channels
PublicationWhen parameters of mobile telecommunication channels change rapidly, classical adaptive filters, such as exponentially weighted least squares algorithms or gradient algorithms, fail to estimate them with sufficient accuracy. In cases like this, one can use identification methods based on explicit models of parameter changes such as the method of basis functions (BF). When prior knowledge about parameter changes is available the...
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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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Energy-Efficient Self-Supervised Technique to Identify Abnormal User Over 5G Network for E-Commerce
PublicationWithin the realm of e-commerce networks, it is frequently observed that certain users exhibit behavior patterns that differ substantially from the normative behaviors exhibited by the majority of users. The identification of these atypical individuals and the understanding of their behavioral patterns are of significant practical significance in maintaining order on e-commerce platforms. One such method for accomplishing this objective...
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Voltage Control of a Stand-Alone Multiphase Doubly Fed Induction Generator
PublicationThis article presents a multiphase doubly fed induction generator (MDFIG) with a dedicated and unique control algorithm in a stand-alone wind energy conversion system. The algorithm has been developed and elaborated in the case of different emergency modes. Compared with the traditional double-fed induction generator, the MDFIG has increased reliability, reduced current level per phase, and low rotor harmonic currents. The control...
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Automated network control and supervision
PublicationPrzedstawiono ogólne problemy związane z postępem w zakresie integracji systemów informatycznych w elektroenergetyce. Podano zasady budowy struktury systemów sterowania i nadzoru.
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Feedback control of water quality
PublicationSformułowano problem sterowania jakością wody w sieciach wodociągowych i następnie zaproponowano podejście do projektowania sterowania stężeniem chloru w takich sieciach, bazujący na estymacji parametrów oraz sterowaniu adaptacyjnym. Podejście wykorzystuje założenie, że w sieci wodociągowej istnieją punkty wstrzykiwania chloru. Zależność typu wejście-wyjście pomiędzy stężeniem chloru w węźle dozowania i monitorowania jest modelowana...
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Technical foundations for noninvasive assessment of changes in the width of the subarachnoid space with near-infrared transillumination-backscattering sounding (NIR-TBSS)
PublicationPraca opisuje metodę transiluminacji w bliskiej podczerwieni umożliwiającą nieinwazyjne monitorowanie zmian szerokości przestrzeni podpajęczynówkowej oraz amplitudy tętnienia naczyń powierzchniowych mózgu.
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Optimal linear control theory in power system application
PublicationPrzedstawiono syntezę stabilizatora systemowego przy wykorzystaniu metodyki Hinf. Zaprojektowany regulator umożliwia uzyskanie lepszych rezultatów w porównaniu z regulatorem odniesienia w szerokim zakresie zmian punktu pracy.
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Fault diagnosis of analog piecewise linear circuits based on homotopy
PublicationArtykuł opisuje weryfikację metodą diagnostyki analogowych układów odcinkowo-liniowych opartą na podejściu homotopijnym. Homotopia przekształca jedną funkcję f(x) w inną funkcję g(x) poprzez zmianę parametru homotopii tî[0,1]. Ścieżka homotopijna pokazuje drogę od punktu x0 z dziedziny funkcji f(x) do odpowiadającego mu punktu x* funkcji g(x). Idea metody zakłada wykorzystanie funkcji f(x) do opisu diagnozowanego układu w stanie...
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Fast recursive basis function estimators for identification of time-varying processes
PublicationW pracy wprowadzono nową kategorię filtrów adaptacyjnych opartych na metodzie funkcji bazowych i wykorzystujących koncepcję postfiltracji. Proponowane algorytmy pozwalają połączyć niską złożoność obliczeniową i dobre właściwości śledzące.
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Fault diagnosis in electronic circuits based on bilinear transformation in 3-D and 4-D spaces
PublicationPrzedstawiono ideę nowych metod diagnostycznych 3-D i 4-D opartych na przek-ształceniu biliniowym. Metody te bazują na transformacjach operujących odpo-wiednio w trzy i czterowymiarowych przestrzeniach funkcji układowych. Dlatych metod omówiono algorytm lokalizacji i identyfikacji pojedynczych uszko-dzeń parametrycznych w liniowych układach elektronicznych oraz algorytm lo-kalizacji i identyfikacji pojedynczych uszkodzeń...
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Speed observer system for advanced sensorless control of induction motor.
PublicationW pracy przedstawiono obserwator prędkości silnika asynchronicznego zastosowany w układzie sterowania ze zmiennymi multiskalarnymi oraz regulatorem predykcyjnym prądu. Zawarto wyniki badań symulacyjnych i eksperymentalnych.
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An advanced low-cost sensorless induction motor drive
PublicationW artykule przedstawiono układ sterowania silnikiem asynchronicznym klatkowym pracujący bez pomiaru prędkości obrotowej. Układ zrealizowano na tanim procesorze stałoprzecinkowym. aspekty praktyczne realizacji układu rozpatrzono na podstawie uzyskanych wyników z symulacji i eksperymentu.
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Synthesis and biological evaluation of 2,7-Dihydro-3H-dibenzo[de,h]cinnoli- ne-3,7-done derivatives a novel group of anticancer agents active on a multidrug resistance cell line.
PublicationZsyntezowano serię pochodnych pirydazonu z jednym lub dwoma łańcuchami bocznymi w różnych pozycjach chromoforu tetracyklicznego. Związki wykazały aktywność cytoksyczną na mysią białaczkę L1210 i ludzką k562 oraz na linii komórkowej oporności krzyżowej MDR (k562/DX). Dwa najbardziej aktywne związki przetestowano in vivo na mysiej białaczce P388. Wykazały one aktywność przeciwnowotworową porównywalną z aktywnością Mitoxantronu.
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Fast algorithms for identyfication of periodiccaly varying systems.
PublicationPraca dotyczy identyfikacji obiektów o parametrach zmieniających się w sposób okresowy. Zaproponowane algorytmy śledzenia parametrów cechują się niską złożonością obliczeniową, typową dla podejścia gradientowego a zarazem wysoką jakością śledzenia typową dla złożonych algorytmów opartych na metodzie funkcji bazowych.
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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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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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Non-Adaptive Speed and Position Estimation of Doubly-Fed Induction Generator in Grid-Connected Operations
PublicationThe nonadaptive speed and position estimation scheme for a doubly-fed induction generator (DFIG) is presented in this article. The observer structure is based on the extension of the mathematical model of DFIG to the introduced H vector. Based on the defined H vector, the nonadaptive position and speed estimation is proposed. The Lyapunov method is extended to the practical stability theorem to stabilize the structure. The classic...