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Search results for: rms line voltage
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Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
PublicationAmines are important biological compounds, and so their analysis and monitoring in various matrices is worthy of investigation and development.Due to the polar nature of amines, chromatographic analysis of free amines is generally unsatisfactory owing to adsorption and decomposition of the solute on the column, resulting in peak tailing and losses. Therefore, many derivatization reactions are employed to reduce the polarity, improve...
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Zastosowanie aplikacji internetowych i e-learningu w zarządzaniu kompetencjami: studium przypadku.
PublicationCel. Integracja efektywnego zarządzania procesami pracy i wykorzystania potencjału zasobów ludzkich warunkuje rozwój organizacji. Jest to szczególnie istotne w organizacjach publicznych, w których wyniki pracy nie zawsze są zgodne z oczekiwanymi standardami. Prezentowana praca stanowi studium przypadku zarządzania kompetencjami w administracji publicznej z wykorzystaniem narzędzi informatycznych na przykładzie polskiej Policji. Metoda....
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Asymmetrical Modes in Polyphase Motors and Drives
PublicationThe effect of power supply and/or motor asymmetry on the phase-load distribution and the ripple of electromagnetic torque in a polyphase drive is studied by the method of symmetrical components. It is shown that the presence of asymmetry causes the mapping of all harmonics in the supply voltage into all planes of symmetrical components and eliminates the possibility of independent control of harmonics. The dynamic model of a five-phase...
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Particle Image Velocimetry Measurements of Airflow in Electrohydrodynamic Device for Dust Particle Collection
PublicationIn this paper the electrohydrodynamic (EHD)device for gas pumping and cleaning is presented. To induce an airflow in this EHD device corona discharge was used. The discharge was generated between the one-sided spike electrodes and the plate electrodes. An asymmetric electric field and generated discharge result in unidirectional gas flow through the EHD device. The current-voltage characteristics were measured and the corona discharge...
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Effect of the let-through energy of overcurrent protective devices on the temperature of conductors during short-circuits
PublicationThe scope of the verification of low-voltage systems covers the earth fault loop impedance measurement. This measurement is usually performed with the use of low-value current meters, which force a current many times lower than the one occurring during a real short-circuit. Therefore, the international standard recommends consideration of the increase of resistance of conductors with the increase of temperature, which may occur...
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Polyarmonic model of synchronous generator for analysis of autonomous power generation systems
PublicationAbstract: This paper presents the polyharmonic modelling of synchronous generator (SG) in machine variables. The simple geometry and windings physical layout has been used for inductance calculations of a salient-pole SG. The main advantage of this model is the ease of describing an autonomous power generation system (APGS) in terms of its topology and thus providing effective analysis at the static and dynamic states, both for...
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Particle Image Velocimetry Measurements of Airflow in Electrohydrodynamic Device for Dust Particle Collection
PublicationIn this paper the pumping effect of air in the electrohydrodynamic (EHD) device for dust particle collection is presented. To induce an airflow in this EHD device corona discharge was used. The discharge was generated between the one-sided spike electrodes and the plate electrodes. The asymmetric electric field and generated discharge resulted in a unidirectional airflow through the EHD device. The current-voltage characteristics...
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Application of wet powder spraying for anode supported solid oxide fuel cell with a perowskite SrTi0.98Nb0.02O3-d anode
PublicationAnode-supported solid oxide fuel cell with SrTi0.98Nb0.02O3–d anode, yttria-stabilized zirconia electrolyte and La(Ni0.6Fe0.4) O3d cathode has been successfully fabricated and evaluated. Process of anode support fabrication has been presented. Wet powder spraying and high temperature sintering method have been studied and applied to deposit the thin electrolyte layer.In order to improve catalytic properties of the anode, it has...
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Implementation of DEIS for reliable fault monitoring and detection in PEMFC single cells and stacks
PublicationDynamic Electrochemical Impedance Spectroscopy (DEIS) was presented as novel method for diagnostic and monitoring of PEMFC stack and single cells operation. Impedance characteristics were obtained simultaneously with current - voltage characteristics for stack and each individual cell. Impedance measurements were performed in galvanodynamic mode. It allowed to compare performance of each cell and identification of faulty cell operation...
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Power Electronic Transformer For Smart Grid Application
PublicationIn this paper the control system of Power Electronic Transformer (PET) for the Smart Grid application is proposed. The structure of PET is based on two Cascaded H-bridge (CHB) converters. The electrical energy is transferred between converters using Dual-Active-Bridges (DAB) and high-frequency transformers. This type of coupling has been used to connect the DC-links of all H-bridges. The proposed control system for PET makes it...
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Interpretacja niepewności pomiarowych systemów DCS przy cieplno-przepływowym diagnozowaniu bloków energetycznych
PublicationW rozdziale przedstawiono możliwość interpretacji niepewności wyników pomiarów parametrów charakteryzujących parametry obciążenia i otoczenia bloków energetycznych oraz wyników pomiarów parametrów czynników roboczych wewnątrz bloku. Analizą objęto zarówno wyniki pomiarów służące do wyznaczania symptomów niesprawnej pracy w cieplno-przepływowej diagnostyce off-line jak i niepewności określania symptomów. Przedyskutowano możliwość...
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On Applications of Fractional Derivatives in Circuit Theory
PublicationIn this paper, concepts of fractional-order (FO) derivatives are discussed from the point of view of applications in the circuit theory. The properties of FO derivatives required for the circuit-level modelling are formulated. Potential problems related to the generalization of transmission line equations with the use of FO derivatives are presented. It is demonstrated that some of formulations of the FO derivatives have limited...
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Problematyka symulatorów neuronowych złożonych obiektów energetycznych
PublicationSymulatory neuronowe charakteryzują się bardzo krótkim czasem obliczeń. W odpowiedzi na pytanie o możliwość zastosowania tego typu urządzeń w systemach diagnostyki on-line złożonych obiektów technicznych, podjęto próbę zbudowania neuronowego symulatora parowego bloku energetycznego. W artykule zawarto ocenę powstałego symulatora pod kątem przydatności do tego typu zastosowań oraz przedstawiono proces jego budowania w celu wskazania...
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Self-assembled concentric stripes of diamond particles by a pinning-depinning mechanism
PublicationWe describe the novel mechanism of spontaneous formation of the concentric stripe patterns of microdiamonds via gradual solvent evaporation from a suspension confined in a teardrop well. The self-organized patterns exhibit a series of arcs with regular spacings varying between hundreds of micrometers and millimeters. They result from an interplay between the directional forced circulation of the solvent and a stick-slip movement...
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Procedury diagnostyczne badania izolacji maszyn elektrycznych
PublicationArtykuł opisuje stosowane w praktyce procedury diagnostyki off-line dla silników elektrycznych niskiego i średniego napięcia. Poza pomiarem rezystancji izolacji do eksploatacji wprowadza się metody impulsowe z dodatkową rejestracją impulsów wyładowań niezupełnych. Analiza odpowiedzi izolacji na oscylacyjne przebiegi napięcia zasadniczo poprawia możliwość wykrywania wewnętrznych uszkodzeń - w tym między zwojowych – w układzie...
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Instantaneous impedance monitoring of AA 7075 aluminum alloy corrosion in borate buffer with admixed chloride ions
PublicationThe study presents a research capabilities of Dynamic Electrochemical Impedance Spectroscopy (DEIS) as a tool used for instantaneous on-line monitoring of corrosion processes on the example of AA 7075 aluminum alloy. A borate buffer with admixed chloride ions in a quantity ranging from 0.05 to 25 mM was used to represent different types of corrosion attack. The surface of samples specimens was evaluated before and after the tests...
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EM-Driven Multi-Objective Design of Impedance Transformers By Pareto Ranking Bisection Algorithm
PublicationIn the paper, the problem of fast multi-objective optimization of compact impedance matching transformers is addressed by utilizing a novel Pareto ranking bisection algorithm. It approximates the Pareto front by dividing line segments connecting the designs found in the previous iterations, and refining the obtained candidate solutions by means of poll-type search involving Pareto ranking. The final Pareto set is obtained using...
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Transmisja w kanale hydroakustycznym w warunkach NLOS
PublicationTransmisja danych w kanale hydroakustycznym w warunkach NLOS (ang. Non-Line-Of-Sight) jest szczególnie problematyczna. Dlatego podjęto próbę opracowania bezprzewodowej komunikacji podwodnej i jej przebadanie w warunkach NLOS. Zastosowano modulację MFSK (ang. Multiple Frequency-Shift Keying), przesyłając pojedynczy bit na dwóch nośnych, oraz odbiór zbiorczy. Uzyskane wyniki potwierdziły przydatność opracowanej techniki do transmisji...
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A Cross-Team Collaborative Evaluation of a CRM System
PublicationThis paper presents an analysis of an usability evaluation a CRM (Customer Relationship Management) performed by a team composed of external usability experts jointly with a CRM staff. The evaluation process differed from a classical scheme known from former projects, including some new elements resulting from a specific context of this study. These novel elements resulted in reshaping the role of the CRM system and considering...
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Estimation of a single balun parameters on the base of back-to-back measurements
PublicationA method of estimation of a single balun S parameters based on the measured parameters of back-to-back configuration is presented in the paper. Proposed approach is to measure two back-to-back circuits: i) direct connection of baluns and ii) connection with additional transmission line segment between the baluns. Coupling effects in both circuits are calculated from full-wave simulations. Next they are applied to estimate the parameters...
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A testing method of analog parts of mixed-signal electronic systems equipped with the IEEE1149.1 test bus
PublicationA new solution of the JTAG BIST for testing analog circuits in mixed-signal electronic microsystems controlled by microcontrollers and equipped with the IEEE1149.1 bus is presented. It is based on a new fault diagnosis method in which an analog circuit is stimulated by a buffered signal from the TMS line, and the time response of the circuit to this signal is sampled by the ADC equipped with the JTAG. The method can be used for...
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Novel Structure and EM-Driven Design of Small UWB Monopole Antenna
PublicationA novel structure of a small UWB monopole antenna is presented. In our approach, a compact size is achieved by means of a meander line for current path enlargement as well as the two parameterized slits that introduce additional degrees of freedom helping to ensure good impedance matching. The antenna design is carried out using surrogate-based optimization involving variable-fidelity EM simulations. This allows us to simultaneously...
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A Special Section on Intelligent User Interfaces in Healthcare (IUIH)
PublicationA concept of interface has evolved from the first appearance in the form of a command line interface to the established use of direct manipulation or WIMP (windows, icons, menus and pointing) interfaces in nearly all applications. Intelligent user interfaces (IUI) form a subfield of Human-Computer Interaction research. Optimal human-computer interactions are defined as ones where users are able to perform complex tasks more quickly...
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Application of Survey Simulator for Museums
Publication“Virtual Museum” is currently a very popular form of presenting museums’ collections of artefacts as well as an approach to archaeological research [1], [2], [3]. The term “virtual” can be understood in many ways – from a simple collection of on-line photographs, through multidirectional viewable panorama pictures, to complete interactive models of the real world, including 3-dimensional (3D) geometry, physical properties and many...
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New clicked full agonists of the estrogen receptor β
PublicationA click chemistry approach was used to synthesize a series of 1,4-diaryl-substituted 1,2,3-triazoles designed to behave as estrogen receptor (ER) ligands. We studied their affinities for both receptors α and β, their agonist activities in a cell-based luciferase reporter assay and their effect on the proliferation of the hormone-dependent MCF-7 cell line. We found two compounds (3a and 3c) that behave as selective full agonists...
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DWUKIERUNKOWY PRZEWODOWY SYSTEM TRANSMISJI MOWY PRZY WYKORZYSTANIU TECHNOLOGII BPL
PublicationMonitorowanie pracowników w środowisku podziemnym jest niezwykle ważnym zadaniem. Z uwagi na możliwe zagrożenia, konieczne jest opracowanie niezawodnego systemu komunikacji głosowej pomiędzy personelem a przełożonym. Dzięki wysokiej odporności na uszkodzenia mechaniczne, kable zasilające pracujące w technice BPL (Broadband over Power Line) wydają się doskonałym rozwiązaniem. W pracy przedstawiono w pełni funkcjonalny dwukierunkowy...
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A newly-developed model for predicting cutting power during wood sawing with circular saw blades
PublicationIn the classical approach, cutting forces and cutting power in sawing processes of orthotropic materials such as wood are generally calculated on the basis of the specific cutting resistance kc (cutting force per unit area of cut). For every type of sawing kinematics (frame saws, band saws and circular sawing machines) different empirical values of specific cutting resistance kc have to be applied. It should be emphasised that...
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Novel molecules containing structural features of NSAIDs and 1,2,3-triazole ring: Design, synthesis and evaluation as potential cytotoxic agents
PublicationFor the first time the template containing structural features of more than one NSAIDs and the 1,2,3-triazole ring was explored for the identification of potential cytotoxic agents. These new and complex molecules were predicted to be effective inhibitors of PDE4B by molecular modelling studies in silico. The multi-step synthesis of these compounds were carried out starting from the well-known drug nimesulide and involved the use...
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In Vitro Studies on Nanoporous, Nanotubular and Nanosponge-Like Titania Coatings, with the Use of Adipose-Derived Stem Cells
PublicationIn vitro biological research on a group of amorphous titania coatings of different nanoarchitectures (nanoporous, nanotubular, and nanosponge-like) produced on the surface of Ti6Al4V alloy samples have been carried out, aimed at assessing their ability to interact with adipose-derived mesenchymal stem cells (ADSCs) and affect their activity. The attention has been drawn to the influence of surface coating architecture and its physicochemical...
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Structure, Physicochemical and Biological Properties of an Aqua (2,2′,2′′-Nitrilotriacetato)-oxidovanadium(IV) Salt with 4-Methylpyridinium Cation
PublicationThe crystal structure of a nitrilotriacetate (nta) oxidovanadi-um(IV) salt with 4-methylpyridinium cation, [4-Me(Py)H]+, of [4-Me(Py)H][VO(nta)(H2O)] stoichiometry was determined. The com-plex comprises a discrete mononuclear [VO(nta)(H2O)]–coordinationentity that can be rarely found among other known compounds con-taining nitrilotriacetate oxidovanadium(IV) moieties. The complex wascharacterized by spectroscopic (IR and EPR) methods,...
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Surrogate-assisted EM-driven miniaturization of wideband microwave couplers by means of co-simulation low-fidelity models
PublicationThis article proposes a methodology for rapid design optimization of miniaturized wideband couplers. More specifically, a class of circuits is considered, in which conventional transmission lines are replaced by their abbreviated counterparts referred to as slow-wave compact cells. Our focus is on explicit reduction of the structure size as well as on reducing the CPU cost of the design process. For the sake of computational feasibility,...
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Investigation on polypropylene friction stir joint: effects of tool tilt angle on heat flux, material flow and defect formation
PublicationTool tilt angle (TTA) is a critical factor that can control material flow in polymeric materials' friction stir joining (FSJ). This study selected a TTA range between 0° to 4° for FSJ of polypropylene (PP) polymer sheet. A modified computational fluid dynamic (CFD) technique was implemented to gain a deep understanding of the effects of TTA during FSJ of PP. The PP joint's internal flow, defect formation, heat generation, and tensile...
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The Impact of Wind Generation on the Transmission System
PublicationThis article has been published to investigate the im-pact of the wind power on the power system- this is a system dependent issue that requires to perform sys-tem specific impact study. This paper discusses the impact of power flow, short circuit current, power quali-ty, voltage stability and the power system during the connection of a wind farm into transmission system. W referacie omówiono wpływ farm wiatrowych na pracę systemu...
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Time-current tripping characteristics of RCDs for sinusoidal testing current
PublicationLow-voltage electrical installations are verified initially – before being put into operation, as well as periodically – during their utilization. According to the IEC standards, the scope of the verification includes measurements of both the tripping current and the disconnection time of residual current devices (RCDs). Experiences in RCDs testing show that disconnection times of two or more similar RCDs can be quite different....
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Application of Barkhausen effect in the impact assessment of welding to internal stress distribution in steel
PublicationThe paper presents identification method of internal stresses in plane steel elements in the chase of deliverance and welding assembly. The assessment was made by means of a non-destructive experimental method based on measurements incorporating local external magnetic field and the measurement of induced voltage, including Barkhausen noise. This method allows a degradation assessment due to internal and external actions, causing...
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Application of Barkhausen effect in the impact assessment of welding to internal stress distribution in steel
PublicationThe paper presents identification method of internal stresses in plane steel elements in the chase of deliverance and welding assembly. The assessment was made by means of a non-destructive experimental method based on measurements incorporating local external magnetic field and the measurement of induced voltage, including Barkhausen noise. This method allows a degradation assessment due to internal and external actions, causing...
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Automatic tuning of a resonant circuit in wireless power supply systems for biomedical sensors
PublicationIn this paper, a tuning method of a resonant circuit suited for wireless powering of miniature endoscopic capsules is presented and discussed. The method allows for an automatic tuning of the resonant frequency and matching impedance of a full wave rectifier loading the resonant circuit. Thereby, the receiver tunes so as to obtain the highest power efficiency under given conditions of transmission. A prototype receiver for wireless...
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Practical aspects of testing superconducting electromagnets by the capacitor discharge method taking into account the non-linearity of circuit parameters
PublicationThe article presents selected issues related to the development and testing of the diagnostics systems dedicated for superconducting electromagnets. The systems were constructed to assess the production quality of superconducting electromagnets of the SIS100 synchrotron, a new accelerator being built as part of the Facility of Antiproton and Ion Research (FAIR). One of the systems is used for automatic checking of electrical connection...
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Self-Testing of Analog Parts Terminated by ADCs Based on Multiple Sampling of Time Responses
PublicationA new approach for self-testing of analog parts terminated by analog-to-digital converters in mixed-signal electronic microsystems controlled by microcontrollers is presented. It is based upon a new fault diagnosis method using a transformation of the set of voltage samples of the time response of a tested analog part to a square impulse into localization curves placed in a multidimensional measurement space. The method can be used...
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Performance Analysis of the "Intelligent" Kirchhoff- Law - Johnson-Noise Secure Key Exchange
PublicationThe Kirchhoff-law - Johnson-noise (KLJN) secure key distribution system provides a way of exchanging theoretically secure keys by measuring random voltage and current through the wire connecting two different resistors at Alice’s and Bob’s ends. Recently new advanced protocols for the KLJN method have been proposed with enhanced performance. In this paper, we analyze the KLJN system and compare with the „intelligent” KLJN (iKLJN)...
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Photoelectrochemical properties of BIMEVOX (ME=Cu, Zn, Mn) electrodes in contact with aqueous electrolyte
PublicationLayered oxide Bi4O2O11 and mixed oxides of bismuth, vanadium and a third metal (ME = Cu, Zn, Mn) were synthesized and characterized using XRD, Raman and SEM. The energy band gap (Eg) of samples determined using UV–VIS reflectance spectra equals to 2.46, 2.34, 2.27 and 2.18 eV for Bi4V2O11, BICUVOX (Bi2V1 − xCuxO5.5 − 3x/2), BIZNVOX (Bi2V1 − xZnxO5.5 − 3x/2) and BIMNVOX (Bi2V1 − xMnxO5.5 − x/2) (x = 0.1), respectively. Open circuit...
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Secondary arc modelling for single pole reclosing analyses
PublicationThe paper discusses two evaluation methods of single pole auto-reclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage calculation results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a nonlinear secondary arc model implementation is presented. The paper presents the study results for the three types of EHV transmission...
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Filtering EBG Structures Implemented in Coplanar Waveguide Feedline of Planar Slot Antenna
PublicationA novel compact dual-band slot antenna fed by a coplanar waveguide (CPW) incorporating electromagnetic band gap (EBG) structures has been proposed. At first, a classic wideband slot antenna fed by a CPW, dedicated to work in 2 ÷ 18 GHz band, has been designed. Subsequently, by adding simple EBG filtering structures into a CPW feedline, a dual-band performance ranging from 2.5 to 5.3 GHz and from 13.5 to 16.3 GHz, with the voltage...
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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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Cross-Bonding of MV Cable Lines for Energy Losses Decrease
PublicationCurrently, almost all medium voltage cable lines (MV) operate with the return wires earthed at both ends of the cable. Such a way of operation causes that during normal states of operation as well as during disturbances, e.g. short-circuits, in the return wires induce currents whose values mainly depend on the currents flowing in the phase wires. These currents in normal operating states are a source of additional energy losses...
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Uproszone modelowanie sieci dystrybucyjnej na potrzeby analiz przyłączeniowych
PublicationW artykule przedstawiono rozważania na temat sposobu modelowania sieci średniego (SN) i niskiego (nn) napięcia na potrzeby wykonywania analiz przyłączeniowych przez operatorów sieci dystrybucyjnej. Przeprowadzono dyskusję na temat możliwych do wykonania uproszczeń w modelowaniu sieci, które są do zaakceptowania z punktu widzenia uzyskiwanego wyniku końcowego. Głównym elementem wymuszającym uproszenia w modelowaniu jest środowisko...
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Modelowanie matematyczne górnej sieci trakcyjnej dla potrzeb diagnostyki odbieraków prądu
PublicationGórna sieć trakcyjna jest obecnie najbardziej skutecznym sposobem zasilania kolejowych pojazdów elektrycznych. Wzrost prędkości pojazdów zwiększa pobór mocy i wymaga zapewnienia właściwej współpracy odbieraków prądu pojazdów z siecią jezdną. Metody modelowania i projektowania wspomaganego komputerowo dla górnej sieci trakcyjnej są obecnie na całym świecie szeroko rozwijane. W artykule przedstawiono nowy model matematyczny elementów...
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Inception and Propagation of Electrical Trees in the Presence of Space Charge in HVAC Extruded Cables
PublicationThis paper presents the space charge impact on the inception and propagation of electrical trees in cross-linked polyethylene (XLPE) insulation via simulations and experimentation. A 3D finite element analysis (FEA)-based modeling is proposed to simulate electrical trees via a needle embedded on the XLPE insulation. The proposed FEA model demonstrates the influence of the space charge magnitude and polarity on the initiation of...
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Control Strategy of a Five-Phase Induction Machine Supplied by the Current Source Inverter With the Third Harmonic Injection
PublicationIn the five-phase induction machine (IM), it is possible to better use the electromagnetic circuit than in the three-phase IM. This requires the use of an adequate converter system which will be supplied by an induction machine. The electric drive system described, in this article, includes the five-phase induction machine supplied by the current source inverter (CSI). The proposed novelty—not presented previously—is the control...
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Techniki śródoperacyjnego monitorowania EKG
PublicationZ badania EKG lekarze uzyskują szereg cennych informacji niezbędnych do prawidłowego podejmowanie ważnych decyzji terapeutycznych. EKG stało się pierwszym parametrem monitorowanym standardowo i w sposób ciągły podczas znieczulenia. Współczesna technika umożliwia nie tylko ciągłe monitorowanie zapisu EKG, a także transmisję danych on-line do dowolnego miejsca w szpitalu, i ich cyfrową rejestrację. Najistotniejszym kryterium przydatności...