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Search results for: HARMONIC CURRENTS COMPENSATION
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Engineering TADF, Mechanochromism, and Second Harmonic Up- conversion Properties in Regioisomeric Substitution Space
PublicationThis research article explores the distinct TADF efficiency of three donor-acceptor based regio-isomers: DPAOCN (ortho- isomer), DPAMCN (meta-isomer), and DPAPCN (para-isomer). DPAPCN exhibits maximum TADF efficiency in both solution and solid-state with an impressive reverse inter-system crossing (RISC) rate of ~ 106 s-1; the underlying cause being the minimum singlet-triplet splitting energy or ∆EST and maximum SOC (spin-orbit...
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Second and third harmonic nonlinear optical process in spray pyrolysed Mg:ZnO thin films
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Quality Improvement of Wear-Resistant Coatings in Plasma Spraying Integrated with High-Energy Heating by High Frequency Currents
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Formation of high-carbon abrasion-resistant surface layers when high-energy heating by high-frequency currents
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Influence of attenuation on self-organized second-harmonic generation in a germanium-doped microstructured silica fiber
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Harmonic analysis of the current of an electric system simulating the electrode process in conditions of linearly changing potential
PublicationAnalizowany był prąd elektrycznego modelu symulującego pierwszorzędową reakcję elektrodową zachodzącą w warunkach liniowo zmieniającego się potencjału z nałożonym sygnałem sinusoidalnym. Pokazano, że transformacja Fouriera nie odzwierciedla zmian amplitudy składowych komponentów w funkcji potencjału. Także matematycznie wykazano, że zastosowanie transformacji Gabora do analizy spektralnej pozwala uzyskać poprawną dekompozycję częstotliwościową....
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Badania kompensacji luzów osiowych w hydraulicznych silnikach satelitowych = Researcg of axial clearances compensation in hydraulic satellite motors
PublicationW pracy doktorskiej przedstawiono koncepcje silnika z mechanizmem satelitowym III typu. Istotną nowością w koncepcji tego typu silnika satelitowego jest zastosowanie nowego specjalnego rozwiązania kompensacji luzów osiowych dla zmniejszania przecieków przez szczeliny czołowe mechanizmu. Ma to zapewnić ich eksploatację również z cieczami roboczymi o bardzo małych lepkościach i możliwość uzyskania małych prętkości obrotowych.
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The effect of a polyharmonic structure of the perturbation signal on the results of harmonic analysis of the current of a first-order electrode reaction
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Exactly solvable model of two interacting Rydberg-dressed atoms confined in a two-dimensional harmonic trap
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Second harmonic generation on crystalline organic nanoclusters under extreme nanoconfinement in functionalized silica–benzil composites
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Enhancement of the efficiency of the third harmonic generation process in ZnO:F thin films probed by photoluminescence and Raman spectroscopy
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Optimized Space Vector Modulation strategy for five phase voltage source inverter with third harmonic injection
PublicationThis paper presents a simple and an effective SVM algorithm for five-phase Voltage-Source Inverters with the possibility to control independently the voltage vectors for fundamental and auxiliary orthogonal subspaces. The essential benefit is that output voltage is generated using only four active voltage vectors with limited numbers of switching. In the proposed solution, four active vectors are arbitrary chosen, independent of...
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Wpływ cewek kompensujących na lokalne wartości pola własnego okrętu = Influence of compensation coils on local magnetic field of ship
PublicationObiekt ferromagnetyczny umieszczony w polu magnetycznym Ziemi powoduje lokalne zaburzenie równomierności rozkładu tego pola. Kształt i rozmiary zaburzenia zależy od wielu czynników, w tym m.in. od rozmiarów i kształtu obiektu, od jego właściwości ferromagnetycznych i od położenia względem wektora ziemskiego pola magnetycznego. W celu minimalizacji pola własnego okrętu na rzeczywistych obiektach umieszcza się uzwojenia kompensacyjne....
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Heart Rate Asymmetry, Its Compensation, and Heart Rate Variability in Healthy Adults during 48-h Holter ECG Recordings
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Two-electron entanglement in a two-dimensional isotropic harmonic trap: Radial correlation effects in the low density limit
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Strategic improvement of second and third harmonic generation in multifunctional Cu-Sn-S3 ternary semiconducting thin films
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Improved third harmonic nonlinear optical process upon e-beam irradiation in Cl: ZnO thin films
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Comment on “Entanglement of two interacting bosons in a two-dimensional isotropic harmonic trap” [Phys. Lett. A 373 (2009) 3833]
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Defect engineering, microstructural examination and improvement of ultrafast third harmonic generation in GaZnO nanostructures: a study of e-beam irradiation
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Laser stimulated second and third harmonic optical effects in F: SnO2 nanostructures grown via chemical synthetic route
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Wytwarzanie harmonicznych w zależności od rozkładu ciśnienia fali pierwotnej = Dependence of harmonic generation on primary wave pressure distribution
PublicationRozważano zagadnienie wytwarzania składowych harmonicznych podczas rozchodzenia się w wodzie fal promieniowanych przez źródła kołowe o różnych rozkładach ciśnienia. Model matematyczny zbudowano w oparciu o równanie KZK. Do rozwiązania problemu zastosowano metodę bilansu harmonicznych. Analizowano zmiany składowych harmonicznych ciśnienia w obrębie wiązki akustycznej.
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Third harmonic generation studies of 1.06 μm Nd:YAG laser beam in Li2SO4–MgO–P2O5 glass system-influence of CuO
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Modelling of steady state and transient performance of the synchronous generator considering harmonic distortions caused by non-uniform saturation of the pole shoe
PublicationIn this paper a synchronous generator model is described. This model is developed on the assumption that in loaded and no load conditions the saturation effect affects the pole shoe in a different way. The developed model is based on the multiple saliency model and is formulated using winding function approach in machine variables. The influence of the non-uniform saturation of the pole shoe in load conditions on the performance...
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Nonlinear harmonic amplitudes in air coils above and below a metal plate as a function of tensile strength via finite element simulation.
PublicationOpisano wyniki obliczeń numerycznych (symulacja metodą MES) wpływu naprężeń na amplitudy nieliniowych harmonicznych napięcia indukowanego w cewkach powietrznych umieszczonych nad i pod płytą.
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Influence of Ni ion site occupancy on laser induced third harmonic generation (THG) studies in Li2SO4–MgO–P2O5 amorphous system
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Five-phase induction motor drive with sine-wave filter
PublicationThe paper presents closed loop ac drive with 5 phase induction motor operating with voltage source inverter and sine wave filter. The motor supply voltages and currents have sinusoidal shape. For well known adjustable electric drives the field oriented control method with flux and speed co ntrol can be applied. In the presence of output filter both control and estimation algorithms should be modified due to sine wave filter installation....
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Corrosion behaviour of low carbon steel in artificial seawater using TP, LP, EIS, Harmonic Analysis (HA) and new method Dynamic Electrochemical Impedance Spectroscopy (DEIS)
PublicationZe względu na istotną rolę technik elektrochemicznych w badaniach procesów korozyjnych są one szeroko stosowane w monitorowaniu korozji. Celem niniejszej pracy jest zgromadzenie rezultatów wyników doświadczalnych uzyskanych różnymi technikami i znalezienie korelacji między nimi. Własności korozyjne stali stopowej (AISI 1026) w sztucznej wodzie morskiej zostały zbadane z wykorzystaniem ekstrapolacji tafelowskiej (TP), polaryzacji...
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Laser stimulated third harmonic generation studies in ZnO–Ta 2 O 5 –B 2 O 3 glass ceramics entrenched with Zn 3 Ta 2 O 8 crystal phases
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Metodyka badań rozwojowych nowego typu silników i pomp satelitowych
PublicationResearch and development of new type satellite motors and satellite pumps SM with small geometrical displacement, from 5 to 73 cm3/rev, has been conducted in cooperation with Stosowanie Maszyn company from Katowice (manufacturer of motors and pump SM). The improvement of construction of those machines, especially construction of axial compensation and construction of fluid distribution channels have been the main problem of research...
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Modeling the effect of parasitic capacitances on the dead-time distortion in multilevel NPC inverters
PublicationA simple model is derived and verified for evaluating the effect of parasitic capacitances on the dead-time related voltage distortion in multilevel NPC voltage source inverters. The model permits well-defined and precise compensation of dead-time distortion, exhibiting meaningful improvement on compensation methods neglecting the effects of parasitic capacitances. A simple formula is given for evaluating the capacitances as serial/parallel...
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System of protection against electric shock for circuits with power electronics converters
PublicationModern low voltage circuits are very often equipped with power electronics converters, therefore in these circuits non-sinusoidal earth currents (touch currents) may occur. For non-sinusoidal currents safety criteria should be modified. This paper presents these modified criteria and a computer system of protection against electric shock which can be implemented in circuits with power electronics converters. The system is based...
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Low Frequency Conducted Emissions of Grid Connected Static Converters
PublicationPulse-width modulated rectifiers are nowadays commonly used for AC to DC power conversion. PWM rectification technology is very effective and allows for bidirectional power flow with the possibility of power factor improvement and low-order harmonic emission limitation. Unfortunately, employed PWM boost topology results with generation of input current harmonic distortions in a frequency range tightly correlated to modulation frequency....
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High Frequency Harmonics Emission in Smart Grids
PublicationPulse-width modulated rectifiers are nowadays commonly used for AC to DC power conversion. PWM rectification technology is very effective and allows for bidirectional power flow with the possibility of power factor improvement and low-order harmonic emission limitation. Unfortunately, employed PWM boost topology results with generation of input current harmonic distortions in a frequency range tightly correlated to modulation frequency....
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High Frequency Harmonics Emission of Modern Power Electronic AC-DC Converters
PublicationModern AC/DC converters with bidirectional power flow employing PWM boost topology generate harmonic distortions of input current in relatively high frequency range tightly related to modulation carrier frequency. These frequencies and its multiples in typical applications are usually located in frequency range from single up to several of kHz. Increased harmonic emission in this frequency range can easily and harmfully influence...
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Pharmaceutical care in the neonatal intensive care unit: Perspectives of Polish medical and pharmacy students
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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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Modeling the impact of discretizing rotor angular position on computation of field-oriented current components in high speed electric drives
PublicationModern drives consist of alternating current electric motors, and the field-oriented control (FOC) of such motors enables fast, precise, and robust regulation of a drive's mechanical variables such as torque, speed, and position. The control algorithm, implemented in a microprocessor, requires feedback from motor currents, and the quality of this feedback is essential to a drive's control properties. Motor phase currents are sampled...
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Design of a compact planar transmission line for miniaturized rat-race coupler with harmonics suppression
PublicationThis paper presents an elegant yet straightforward design procedure for a compact rat-race coupler (RRC) with an extended harmonic suppression. The coupler’s conventional λ/4 transmission lines (TLs) are replaced by a specialized TL that offers significant size reduction and harmonic elimination capabilities in the proposed approach. The design procedure is verified through the theoretical, circuit, and electromagnetic (EM) analyses,...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Modernization of the Trailer for Tyre/Road Rolling Resistance Measurements
PublicationIn the article the ways of defining tyre rolling resistance are presented. The advantages of the laboratory tests of tyre/road rolling resistance and the advantages and disadvantages of on the road tyre/road rolling resistance tests are described. The description of the special trailer used for tyre/road rolling resistance measurements designed and constructed in the Faculty of Mechanical Engineering at Gdansk University of Technology,...
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Installation of Compensators in the Power System Transmission Grid
PublicationThe article discusses issues of reactive power compensation in transmission grids, with particular focus on the selection of compensator locations and basic parameters. Attention was focused on modern power electronics systems that ensure full automatic compensator adjustment to voltage or power criteria.
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Fast Real-Time RDFT- and GDFT-Based Direct Fault Diagnosis of Induction Motor Drive
PublicationThis paper presents the theoretical analysis and experimental verification of a direct fault harmonic identification approach in a converter-fed electric drive for automated diagnosis purposes. On the basis of the analytical model of the proposed real-time direct fault diagnosis, the fault-related harmonic component is calculated using recursive DFT (RDFT) and Goertzel DFT (GDFT), applied instead of the full spectrum calculations...
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The Impact of Micro-Sources on Voltage Distortions in a Power Grid
PublicationThe increase in the number of photovoltaic (PV) systems integrated with low voltage (LV) grids has led to a great need to analyse the impact of these systems on the quality of electricity and the reliability of its supply. This paper presents and compares the energy quality requirements imposed by various countries on photovoltaic plants. Then, based on real object tests and simulation in DIgSILENT PowerFactory, the impact has...
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Protection of bridges against stray current corrosion
PublicationA case study of Siennicki Bridge stray current corrosion hazard is presented. A corrosion risk was caused by incorrectly designed tram line traction which goes over the bridge. No dielectric insulation between running rails and bridge steel construction was used. A variety of protection methods against stray currents are described. Characteristics of the endangered bridge were described. Impressed current cathodic protection system...
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Potential changes in an electric field and electrolytic corrosion.
PublicationSources have been described of corrosively hazardous electric fields and methods of determination of the corrosion hazard to metal structures caused by electrolytic corrosion. Results of potential and impedance investigations in the field of stray currents flowing out of a tram traction and in the presence of a defined electric field of low frequency have been presented. Uncertainties have been indicated relating to the generally...
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Neutral point balancing technique for 3-level neutral point clamped converter with servo system
PublicationNeutral point voltage drift compensation technique in 3-level NPC multilevel converter and servo system is described in the paper. Analytical expressions are obtained for power subsystem elements parameters of servo drive system. Simulation of servo system, based on PMSM motor with 3-level NPC converter is considered.
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Topography measurement methods evaluation for entire bending-fatigued fracture surfaces of specimens obtained by explosive welding
PublicationIn this paper, the methods of compensation of differences in the results of entire bending-fatigued fracture surface topographies were presented. The roughness evaluation was performed with a focus variation microscope and confocal surface topography measurement techniques. The differences in the ISO 25178 roughness parameters were investigated and procedures for their compensation were studied. It was found that various types...
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Generalized adaptive comb filters/smoothers and their application to the identification of quasi-periodically varying systems and signals
PublicationThe problem of both causal and noncausal identification of linear stochastic systems with quasiharmonically varying parameters is considered. The quasi-harmonic description allows one to model nonsinusoidal quasi-periodic parameter changes. The proposed identification algorithms are called generalized adaptive comb filters/smoothers because in the special signal case they reduce down to adaptive comb algorithms used to enhance...
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Problems of Connecting Wind Farms to the Power System with HV Cables
PublicationThis paper presents problems caused by connecting wind farms to a power system with high voltage cables. The author highlights possible problems with reactive power compensation, depending on the arrangement of the shunt reactor connection and settings of control systems for reactive power and voltage of the wind farm. The paper also discusses issues of increasing active power losses caused by a shunt reactor installation.