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Search results for: DC VOLTAGE BALANCING
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Fault Loop Impedance Measurement in Circuits Fed by UPS and Principle of Safety Protection
PublicationThis paper indicates a significant problem of uncertainty of fault loop impedance (FLI) measurement in circuits powered from uninterruptible power supply (UPS) (double-conversion AC-DC-AC). The correctly determined value of this impedance, related to the short-circuit current disconnection time and to the reference value, is one of the most important elements that determines the approval of an electrical installation and its receivers...
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Electrohydrodynamic flow patterns and collection efficiency in narrow wire-cylinder type electrostatic precipitator
PublicationRecently, narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application for the cleaning of the exhaust gases emitted by diesel engines. Diesel engines emit fine particles, which are harmful to human and animal health. There are several methods for decrease particulate emission from a diesel engines, but up to now, these methods are not enough effective or very expensive. Therefore,...
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Detekcja i lokalizacja nieprzewodzenia tranzystorów falownika napięcia na podstawie analizy prądu obciążenia
PublicationPrzedstawiono nową metodę detekcji i lokalizacji nieprzewodzenia tranzystorów w falownikach napięcia zasilających silniki indukcyjne małej mocy. Metoda bazuje na monitorowaniu wartości dwóch sygnałów dia-gnostycznych. Pierwszy z nich, wskaźnik braku przepływu prądu, wykorzystano w celu detekcji uszkodzeń. Drugi, stosunek wartości średniej prądu do wartości średniej bezwzględnej, zawiera informacje umożliwiające lokalizację uszkodzonych...
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Current harmonic controller in multiple reference frames for series active power filter integrated with 18-pulse diode rectifier
PublicationThe paper presents the control system and selected results of experimental tests of the AC/DC power converter consisting of an 18-pulse diode rectifier based on coupled reactors and a serial active power filter. Proportional integral controllers with decoupling components are implemented in multiple reference frames for selective line current harmonic suppression. The regulator is provided with a backtracking anti-windup mechanism...
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Multiple output CMOS current amplifier
PublicationIn this paper the multiple output current amplifier basic cell is proposed. The triple output current mirror and current follower circuit are described in detail. The cell consists of a split nMOS differential pair and accompanying biasing current sources. It is suitable for low voltage operation and exhibits highly linear DC response. Through cell devices scaling, not only unity, but also any current gains are achievable. As...
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Switching Regulation in the Control of 5-Phase Permanent Magnet Synchronous Motor Fed by 3×5 Direct Matrix Converter
PublicationMatrix converter is an AC-AC direct power converter comprising of an array of bi- directional switches. It does not require an intermediate DC-link and allows sinusoidal output waveforms with varying amplitudes and frequencies. The configuration of these bi- directional switches decides the number of inputs and outputs...
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Low-frequency noise in Au-decorated graphene–Si Schottky barrier diode at selected ambient gases
PublicationWe report results of the current–voltage characteristics and low-frequency noise in Au nanoparticle (AuNP)-decorated graphene–Si Schottky barrier diodes. Measurements were conducted in ambient air with addition of either of two organic vapors, tetrahydrofuran [(CH2)4O; THF] and chloroform (CHCl3), as also during yellow light illumination (592nm), close to the measured particle plasmon polariton frequency of the Au nanoparticle...
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Assessment of organic coating degradation via local impedance imaging
PublicationThe paper presents a new approach to organic coating condition evaluation at micrometer scale using localized impedance measurements. It is based on atomic force microscopy (AFM) in contact mode. Impedance is measured between conductive AFM tip and metal substrate covered with organic coating. A single-frequency voltage perturbation signal is applied between the electrodes and current response signal is registered. As the tip is...
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Analysis of balancing of four stroke V6 engines
PublicationAnalysis of balance of V6 engines with a common-pin crankshaft depending on a cylinder bank angle and the crank radius to connecting rod length ratios , based on the relations derived, is presented in the paper. The bank angles providing the lowest moment of inertia forces in reciprocating motion, for selected values, were determined. The position of the plane of the main counterweights in order to maximum balance of the moment...
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Optimal state feedback controller for balancing cube
PublicationIn this paper, a nonlinear balancing cube system is considered, the concept for which is based on an inverted pendulum. The main purpose of this work was the modelling and construction of a balancing cube with the synthesis of the control system. The control objectives included swing-up and stabilization of the cube on its vertex at an unstable equilibrium. Execution of the intended purpose required, first, deriving a cognitive...
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The conducted EMI in DC-DC converters
PublicationThis book presents the phenomena of conducted electromagnetic interference (EMI) generation in DC-DC converters. The measurement and simulation are used to analyze the impact of the most important parameters on the character, level and propagation path of interference. In this book, the analysis of the interference generation and propagation is presented on the example of three basic converters. The wide banded behavior of all...
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Natural convection in symmetrically heated vertical channels
PublicationThe study describes natural convection through a vertical channel, open on four sides and bound by two isothermal walls. Both balancing and infrared experimental investigations were performed in air (Pr = 0.71) to estimate the impact of channel width s and wall-to-ambient temperature difference (tw - t∞) on natural convective heat transfer, the formation of air flow patterns and the rate of flow pattern formation. The study was...
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Prediction of ringing frequencies in DC-DC boost converter
PublicationIn the paper ringing phenomena in a DC-DC boost converter is presented. The ringing frequency is calculated using an analytical formula. The necessary wide band models of MOSFET transistor, passive and parasitics are described. The calculation results are verified in simulation and laboratory tests.
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Badania symulacyjne wysokonapięciowej przetwornicy DC/DC
PublicationW artykule zaprezentowano wyniki badań symulacyjnych przekształtnika energoelektronicznego typu DC/DC działającego w układzie niepełnego mostka z transformatorem izolacyjnym pracującym przy dużej częstotliwości. Badania symulacyjne wykonano posługując się pakietem Matlab-Simulink z biblioteką SimPowerSystems. Omówiono problemy zastosowania wysokonapięciowych tranzystorów z izolowaną bramką do konstrukcji przekształtników wysokiego...
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Potential of silicon carbide MOSFETs in the DC/DC converters for future HVDC offshore wind farms
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Comparative analysis of balancing of V6 engines with common- and split-pin crankshafts
PublicationAn analysis of balancing of V6 engines equipped with split-pin crankshafts with any cylinder bank angle based on the mathematical relations derived in the paper was carried out. A comparison of the quality of their balancing with engines equipped with common-pin crankshafts was also carried out. The bank angle ranges beneficial for balancing of moments of inertia forces in reciprocating motion were determined. A mathematical relation...
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Przetwornica dc-dc z miękką komutacją tranzystorów
PublicationW artykule zaprezentowano wyniki badań eksperymentalnych przetwornicy DC-DC o mocy 20[kW], w której ograniczenie komutacyjnych strat mocy zapewniono poprzez wykorzystanie dławika z odczepem oraz dodatkowego obwodu rezonansowego. Przedstawiono wyniki badań eksperymentalnych wpływu wartości parametrów poszczególnych elementów układu przetwornicy na zachowanie warunków miękkiej komutacji.
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Przetwornica dc-dc z miękką komutacją tranzystorów
PublicationW artykule zaprezentowano wyniki badań eksperymentalnych przetwornicy DC-DC o mocy 20[kW], w której ograniczenie komutacyjnych strat mocy zapewniono poprzez wykorzystanie dławika z odczepem oraz dodatkowego obwodu rezonansowego. Przedstawiono wyniki badań eksperymentalnych wpływu wartości parametrów poszczególnych elementów układu przetwornicy na zachowanie warunków miękkiej komutacji.
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Balancing energy processes in turbine engines
PublicationThe article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and PDULQHSURSXOVLRQV\VWHPVZLWKWKHDLPWRDQDO\VHDQGHYDOXDWH EDVLFRSHUDWLQJSDUDPHWHUV7KH¿UVWSDUWSUHVHQWV the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect RIÀRZSDUDPHWHUVDQGFRQVWUXFWLRQDOSURSHUWLHVRIWKHHQJLQHV RQWKHLUSHUIRUPDQFHDQGUHDOHI¿FLHQF\DUH evaluated....
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On the use of a charge balancing method for low energy measurements
PublicationThe paper presents the method for the estimation of the energy consumption of the low-power microcontroller-based devices. Due to high dynamics of the changes of the supply current of the tested devices during the operational cycle, the consumed energy estimation is not easy. In order to avoid disadvantages of known methods, the charge balancing method was employed similarly like in some types of A/D converters.
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Modeling of conducted emission of dc-dc switch-mode converter
PublicationW publikacji zaprezentowano sposób modelowania i wyznaczania emisji przewodzonej zaburzeń elektromagnetycznych w przekształtnikach energoelektronicznych. Na przykładzie przekształtnika DC-DC, zostały dobrane odpowiednie narzędzia CAD do szerokopasmowego modelowania i symulacji przekształtnika energoelektronicznego. Otrzymane rezultaty zostały eksperymentalnie potwierdzone i porównane zarówno w dziedzinie czasu jak i częstotliwości...
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Wielotransformatorowy quasi-rezonansowy przekształtnik DC-DC
PublicationW rozprawie przedstawiono oryginalną koncepcję wielotransformatorowego przekształtnika dwutaktowego dc/dc z wieloma wyjściami o sterowaniu quasi-rezonansowym. Przeprowadzono analizę modelu obwodowego przekształtnika w układzie n-transformatorowym. Na podstawie bilansu energetycznego określono wpływ indukcyjności rozproszenia transformatorów i współczynnika asymetrii obciążenia na uchyb regulacji skrośnej napięć wyjściowych. W celu...
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Voltage Conditions in Low Voltage Grid with Connected Mictogeneration
PublicationThe introduction of distributed generation into a low voltage grid may cause voltage problems in it. The paper discusses the effect of microgeneration on voltage levels in a low voltage grid. A real low voltage grid of considerable length was selected for the analysis. The grid primarily supplies residential buildings in a rural area. Results of tests that consider potential measures which could be applied in this grid to improve...
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Przekształtnik SiC DC-DC z transformatorem macierzowym do pokładowych ładowarek baterii akumulatorów taboru 3kV DC
PublicationBaterie akumulatorów pojazdów trakcyjnych zapewniają zasilanie krytycznych systemów, takich jak sterowanie i oświetlenie. Zgodnie z wymaganiami przemysłu kolejowego, pokładowa ładowarka baterii akumulatorów powinna być urządzeniem kompaktowym, wysokosprawnym, a jednocześnie wysoce niezawodnym. W referacie, do pokładowego ładowania akumulatorów pociągu zaproponowano kompaktowy przekształtnik SiC DC-DC z transformatorem macierzowym...
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Przekształtnik SiC DC-DC z transformatorem macierzowym do pokładowych ładowarek baterii akumulatorów taboru 3kV DC
PublicationBaterie akumulatorów pojazdów trakcyjnych zapewniają zasilanie krytycznych systemów, takich jak sterowanie i oświetlenie. Zgodnie z wymaganiami przemysłu kolejowego, pokładowa ładowarka baterii akumulatorów powinna być urządzeniem kompaktowym, wysokosprawnym, a jednocześnie wysoce niezawodnym. W referacie, do pokładowego ładowania akumulatorów pociągu zaproponowano kompaktowy przekształtnik SiC DC-DC z transformatorem macierzowym...
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Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublicationThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...
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Optimisation of ZVZCS DC/DC converter with tapped inductor.
PublicationW artykule zaprezentowano możliwości wykorzystania dławika z odczepem oraz obwodu LC w celu uzyskania warunków miękkiej komutacji kluczy energoelektronicznych w przetwornicy DC-DC.Na podstawie modelu matematycznego zbadany został wpływ wartości elementów na zachowanie miękkiej komutacji.Przedstawiono wyniki badań symulacyjnych i eksperymentalnych.
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Modelowanie układu przetwornicy rezonansowej dc-dc z miękką komutacją tranzystorów.
PublicationW referacie zaprezentowano model matematyczny przetwornicy DC-DC, który umożliwia przeprowadzenie badań symulacyjnych układu przetwornicy oraz dobór parametrów głównych jej elementów.
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Analysis of energy efficiency of suburban railway transport network
PublicationRising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions...
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A Development of a Capacitive Voltage Divider for High Voltage Measurement as Part of a Combined Current and Voltage Sensor
PublicationThis article deals with the development of capacitive voltage divider for high voltage measurements and presents a method of analysis and optimization of its parameters. This divider is a part of a combined voltage and current sensor for measurements in high voltage power networks. The sensor allows continuous monitoring of the network distribution status and performs a quick diagnosis and location of possible network failures....
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Voltage Transients Transfer over Medium Voltage Instrument Transformers
PublicationThis paper presents voltage harmonic transfer accuracy problems through voltage transformers which are used in power quality monitoring systems in medium and high voltage grids. A simplified lumped parameters circuit model of the voltage transformer is proposed and verified by simulation and experimental investigations. A number voltage transformers typically used in medium voltage grid has been tested in the conducted disturbances...
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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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Voltage Harmonics Transfer through Medium Voltage Instrument Transformers
PublicationVoltage transformers are widely used in power quality monitoring systems in medium and high voltage grids. This paper presents accuracy problems related to voltage harmonics transfer through instrument transformers. A simplified lumped-parameters wideband circuit model of the voltage transformer is proposed and verified by simulation and experimental investigations. A number of voltage transformers have been tested in the frequency...
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Ładowanie baterii akumulatorów przy wykorzystaniu przetwornicy dc/dc ze sterowaniem mikroprocesorowym
PublicationW referacie przedstawiono metodologię procesu ładowania baterii akumulatorów kwasowo - ołowiowych, z wykorzystaniem nowoczesnego prostownika impulsowego (przetwornicy DC/DC), sterowanego mikroprocesorem. Zaprezentowano i omówiono wyniki analizy energetycznej i sprawnościowej dla wybranej metody ładowania. Przedstawiono wady i zalety ładowania akumulatorów kwasowo - ołowiowych prądem o charakterze impulsowym i wysokiej częstotliwości...
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Control of nonlinear and linearized model of self-balancing electric motorcycle
PublicationSelf-Balancing Electric Motorcycle (SBEM) is a dynamic and nonlinear electro-mechanical system. In this paper, the process of mathematical modelling and line-arization of SBEM is presented. The model of the control system in Matlab envi-ronment is implemented. The control system using the PID controller is designed. The operation of particular structures of the PID controller on the simulation model is compared. Due to simulation...
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Non-isolated resonant quasi-Z-source network DC–DC converter
PublicationA novel non-isolated resonant quasi-impedance (quasi-Z)-source network DC–DC converter is proposed. The resonant impedance source network is derived from the quasi-Z-source network by including the autotransformer-based resonant cell instead of the second inductor of the quasi-Z-network. The leakage inductance of the autotransformer and two resonant capacitors connected in series with the autotransformer windings constitute a high-frequency...
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Comparative analysis of switched reluctance motor control algorithms
PublicationПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Comparative analysis of switched reluctance motor control algorithms
PublicationПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublicationNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...
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Analysis of AC/DC/DC Converter Modules for Direct Current Fast-Charging Applications
PublicationThe paper is a comprehensive laboratory comparison study of two galvanic isolated solution off-board battery chargers: (1) Si-based cost-effective case, and (2) SiC-bidirectional ready for vehicle to grid concept case. All circuits are modular, and in both cases the DC/DC converter can be replaced according to the end user requirements (the coupled transformer remains the same and is constructed based on 12xC100 cores to avoid...
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STANY NIEUSTALONE TOWARZYSZĄCE POMIAROWI IMPEDANCJI PĘTLI ZWARCIA W OBWODACH WYJŚCIOWYCH ZASILACZY BEZPRZERWOWYCH UPS
PublicationW pracy przedstawiono metodykę i wyniki pomiarów stanów nieustalonych w zasilaczu bezprzerwowym (UPS) typu on - line. Do rejestracji zdarzeń po stronie zasilania i na wyjściu UPS wykorzystano dwa przyrządy do pomiaru jakości energii elektrycznej zsynchronizowane czasowo. Rejestratory kompresują uzyskane dane pomiarowe, co może wprowadzać dodatkowe błędy pomiaru wielkości mierzonych – napięć i prądów. Dodatkowe rejestracje oscyloskopem...
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Electrohydrodynamic Flow Patterns in a Narrow Electrostatic Precipitator with Longitudinal Wire Electrode for Various Electrode Geometries
PublicationRecently narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application in diesel engines. In this paper results of 2-dimensional (2D) Particle Image Velocimetry (PIV) measurements of the flow patterns in a narrow ESP for a various electrode geometries are presented. The PIV measurements were carried out in the observation plane that is perpendicular to the ESP duct. The ESP was...
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Wpływ parametrów elementów układu przetwornicy rezonansowej dc-dc na zachowanie warunków miękkiej komutacji.
PublicationW artykule zaprezentowano topologię układu przetwornicy rezonansowej DC-DC, zapewniającą bezprądową oraz beznapięciową komutację tranzystorów (ZVZCS). Warunki miękkiej komutacji uzyskano dzięki zastosowaniu dławika dzielonego oraz dodatkowego obwodu LC. W oparciu o badania symulacyjne przeanalizowano wpływ parametrów wybranych elementów na pracę przetwornicy DC-DC.
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
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Problems with microprocessor voltage-to-frequency and frequency-to-voltage converters implementation
PublicationThe article presents the problems of digital voltage-to-frequency and frequency-to-voltage processing. Transducer systems implemented in microprocessor technology are presented, the timing of signals and functioning algorithms are discussed. An analysis of processing errors has been performed and the results of experimental studies of realized systems are presented.
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Improving voltage levels in low-voltage networks with distributed generation – case study
PublicationThe use of distributed generation in low-voltage networks may cause the voltage variation in them, within the wide range. In unfavourable circumstances, the voltage may reach unacceptable values. The paper presents the effect of distributed generation on voltage levels in a selected low-voltage rural distribution network in Poland. An analysis of possible methods for improving voltage levels in this network is conducted. The most...
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FPGA-Based System for Electromagnetic Interference Evaluation in Random Modulated DC/DC Converters
PublicationField-Programmable Gate Array (FPGA) provides the possibility to design new “electromagnetic compatibility (EMC) friendly” control techniques for power electronic converters. Such control techniques use pseudo-random modulators (RanM) to control the converter switches. However, some issues connected with the FPGA-based design of RanM, such as matching the range of fixed-point numbers, might be challenging. The modern programming...
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Experimental test results of an automatic voltage regulator with independent phase voltage controllers
PublicationThe growing number of distributed renewable energy sources and dynamic constant-power loads (e.g. electric vehicle charging stations) pose new challenges for network operators. These changes result in alterations to network load profiles and load flows, leading to greater voltage volatility. One effective solution to these problems can be the use of automatic voltage regulators (AVRs), which stabilize and symmetrize voltage output,...
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Voltage variations and their reduction in a rural low-voltage network with PV sources of energy
PublicationRenewable sources of energy (RES), especially photovoltaic (PV) micro-sources, are very popular in many countries. This way of clean power production is applied on a wide scale in Poland as well. The Polish legal regulations and tariffs specify that every prosumer in a low-voltage network may feed this network with a power not higher than the maximum declared consumed power. In power networks with RES, the voltage level changes...
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Accurate electrothermal modelling of high frequency DC-DC converters with discrete IGBTs in PLECS software
PublicationIn the paper, a novel, improved method of the IGBT junction temperature computations in the PLECS simulation software is presented. The developed method aims at accuracy of the junction temperature computations in PLECS by utilising a more sophisticated model of transistor losses, and by taking into account variability of transistor thermal resistance as a function of its temperature. A detailed description of the proposed method,...