Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "voltage-current" wg kryterium: Temat

  Lista filtrów

Dostawca treści

Wyrównaj
Wyświetlanie 1-15 z 123
Tytuł:
An alternating current calibration method for Helmholtz coil constant based on orthogonal calculation principle
Autorzy:
Zhang, Kuankuan
Cao, Mingxing
He, Jian
Gong, Wenjie
Huang, Yunhua
Powiązania:
https://bibliotekanauki.pl/articles/27311758.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Helmholtz coils constant
alternating current method
induction voltage
orthogonal calculations
Opis:
The Helmholtz coil constant (ℎ) is a crucial standard in magnetic moment measurement devices for permanent magnet materials. To overcome the problem of low accuracy of the direct-current (DC) calibration method, this study used a constant sinusoidal current in the Helmholtz coil and measured the induced voltage of the detection coil with known coil turns and coil area. Subsequently, the ℎ was calculated. The noise signal deduction rate in the induction voltage of the detection coil was greater than 99%, its influence on the induction voltage is less than 0.005%, and the repeatability of the calibration results is 0.003% (1). The results reveal that the alternating current (AC) method and orthogonal calculation (OC) can accurately measure the valid values of the voltage signal under the influence of the spatial stray field during the calibration of ℎ.
Źródło:
Metrology and Measurement Systems; 2023, 30, 3; 549--561
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Armature MMF and electromagnetic performance analysis of dual three-phase 10-pole/24-slot permanent magnet synchronous machine
Autorzy:
Chen, Zhenfei
Xing, Ning
Ma, Hongzhong
Li, Zhixin
Li, Jiayu
Fan, Chenyang
Powiązania:
https://bibliotekanauki.pl/articles/2202550.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dual three-phase winding
fractional-slot
concentrated winding
permanent magnet synchronous machines (SCW-PMSMs)
MMF harmonic analysis
space harmonics
magnet eddy-current loss (ECL)
SVPWM voltage supply
Opis:
Fractional-slot concentrated-winding permanent magnet synchronous machines (FSCW-PMSMs) have a good prospect of application in the drive system of electric and hybrid electric vehicles. However, the armature magnetomotive force (MMF) of FSCWPMSM contains a large number of space harmonics, which induce large magnet eddycurrent loss (ECL). To solve this problem, a dual three-phase 10-pole and 24-slot winding layout is proposed.MMFharmonic analysis shows that the 1st, 7th and 17th space-harmonic winding factors of the proposed winding can be reduced by 100%, 87% and 87% respectively, compared with a dual three-phase 10-pole and 12-slot winding. Electromagnetic performances of the proposed machine under rated sinusoidal current supply and space vector pulse-width-modulated (SVPWM) voltage supply are investigated based on 2D finite-element analysis. It is shown that the proposed machine can meet the requirement of torque and efficiency in the full speed range. Especially, magnet ECL can be reduced greatly due to the reduction of the 7th and 17th space harmonics.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 189--210
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Closed loop ĈUK topology based single phase high performance AC-DC converter
Autorzy:
Hossain, Ismail
Alam, Mohammad Jahangir
Powiązania:
https://bibliotekanauki.pl/articles/41188229.pdf
Data publikacji:
2023
Wydawca:
Politechnika Warszawska, Instytut Techniki Cieplnej
Tematy:
PWM
state space averaging technique
small signal model
Ĉuk topology
voltage loop and current loop
korekcja współczynnika mocy
model małosygnałowy
napięcie
Opis:
This paper focuses on the analysis of a power factor correction (PFC) converter using close loop Ĉuk topology. Regardless of the input line voltage and output load variations, input current drawn by the buck or buck-boost converter is always discontinuous. The Boost converter suffers from high voltage stresses across the power electronic devices. The input current in Ĉuk converter is comparable to boost converter’s input current. In this paper output voltage is controlled by inner current and outer voltage control loop along with power factor correction (PFC). It shows less input current THD (less than 5%), nearly unity power factor and better output voltage regulation of AC-DC converter under variable input voltage and output load. Small signal model analysis is presented for obtaining frequency response of the control loop. The MATLAB Simulink programming environment is used as a simulation tool.
Źródło:
Journal of Power Technologies; 2023, 103, 3; 138-145
1425-1353
Pojawia się w:
Journal of Power Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a Fractional Order Low-pass Filter Using a Differential Voltage Current Conveyor
Autorzy:
Krishna, Battula Tirumala
Janarthanan, Midhunchakkaravathy
Powiązania:
https://bibliotekanauki.pl/articles/24200737.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
current conveyor
differential voltage
differentiator
fractional order
integrator
RC network
simulation
Opis:
In this paper, an active implementation of a differential voltage current conveyor (DVCC) based on a low-pass filter operating in the fractional order domain is presented. The transfer function for a fractional order system is dependent on the rational approximation of sα. Different methods used for calculating the rational approximation, including Carlson, Elkhazalil, and curve fitting, are evaluated here. Finally, to validate the theoretical results, a fractional order Butterworth filter is simulated in the Pspice environment using the 0.5 micrometer CMOS technology with an R-C network-based fractional order capacitor. Additionally, using the Monte Carlo analysis, the impact of current and voltage faults on DVCC response is investigated. It has been inferred that realization with a wider bandwidth is possible.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 2; 17--21
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the Efficiency of the Ozonator in the Process of Water Purification Based on the Corona Discharge
Autorzy:
Abdykadyrov, Askar
Marxuly, Sunggat
Mamadiyarov, Maxat
Smailov, Nunzhigit
Zhunusov, Kanat
Kuttybaeva, Ainur
Amanzholov, Arnay
Orazbekov, Asset
Powiązania:
https://bibliotekanauki.pl/articles/2202354.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
corona discharge
ozonator
sewage
electric current
high voltage
ozonometer
ozone concentration
Opis:
In this research paper, the problem of studying the effectiveness of ozone in the process of water treatment was considered. In the course of the scientific work, a review of domestic and foreign literature was conducted; its advantages and disadvantages were considered. The research paper presented the theoretical and practical methods of water purification with ozone. The main factors influencing the efficiency of the technology in the process of water purification were also considered. It was established that as a technological method of water purification, the efficiency of the ozonation process includes not only the cost of electricity, but also the efficiency of its mixing, ozone dissolution in treated water. In addition, special attention is paid to the final stage of mixing the ozone-air mixture with treated water. From the results obtained, it can be seen that after primary ozonation, the concentrations of chromium, oxidation of permanganate, iron, petroleum products, metal ions and other pollutants significantly decreased. During further water purification, organic and inorganic pollutants are removed in the future (completely or up to the requirements of the standard). However, calcium, magnesium, sulfates, chlorides, pH value, alkalinity and hardness practically do not change. The water quality after primary ozonation according to bacteriological indicators met the requirements of the standard.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 140--151
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of the VSVEM-1140 electro-mechatronic system for testing theasynchronous motors
Autorzy:
Beshta, Oleksandr, senior
Khudolii, Serhii
Djur, Roman
Peltek, Illia
Powiązania:
https://bibliotekanauki.pl/articles/27324352.pdf
Data publikacji:
2023
Wydawca:
Instytut Techniki Górniczej KOMAG
Tematy:
testing and charging stations
high-voltage alternating current electric machines
energy recovery in braking modes
electro-mechatronic system
thermal diagnostics of electric machines
system elektromechaniczny
maszyny elektryczne
diagnostyka
Opis:
The article is devoted to the description of practical experience in testing the alternating current electric machines. The results of combining thecapabilities of digital systems for collecting and processing information with a powerful electromechanical system are presented. Itis the combination of two systems of different purposes that enables creating the state-of-the art diagnostic installations combined into one electro-mechatronic system. Practical results of electric machine tests contain clear explanations of fundamental principles and provide acomprehensive assessment of the conditionof electric machines. They use methods of direct charging the electric machines with the possibility of recuperation of electric energy during tests. Thermal state of electrical machine nodes is monitoredusing the thermal forecasting technologies. Both the methods for various types of tests and means for their implementation are described in detail. This article is intended for engineers involved in designing, manufacturing and testing the electric machines.
Źródło:
Mining Machines; 2023, 41, 4; 240--247
2719-3306
Pojawia się w:
Mining Machines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mostki dwuźródłowe jako nowy rodzaj układów pomiarowych
Two-source Bridges as a New Kind of Measuring Systems
Autorzy:
Warsza, Zygmunt Lech
Powiązania:
https://bibliotekanauki.pl/articles/27312464.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
mostki dwuprądowe
mostki dwunapięciowe
dwa różne wyjścia
dwie rezystancje
przyrosty rezystancji
two-current bridges
two-voltage bridges
simultaneously measurements of two resistances
simultaneously measurements of resistances increments
Opis:
W pracy omawia się podstawowe zależności i stan badań niekonwencjonalnych układów pomiarowych w postaci mostków czteroramiennych o dwu źródłach i dwu wyjściach z obu przekątnych. Dwa jednakowe źródła prądu lub napięcia są odpowiednio dołączone do przeciwległych gałęzi mostka. Podano wzory dla napięć wyjściowych i warunki równowagi obu wyjść mostków dwuźródłowych przy prądzie stałym (DC). Dla mostków dwuprądowych są to równości iloczynów rezystancji ramion przyległych do końcówek każdego z wyjść, a dla mostków dwunapięciowych - równości sum dwu rezystancji ramion. Oba te rodzaje mostków przy zrównoważeniu kolejno każdego z wyjść umożliwiają pomiary dwu różnych rezystancji (lub konduktancji) ich ramion. Ich sygnały wyjściowe zależą zaś od różnych liniowych kombinacji przyrostów rezystancji ramion od wartości w stanach równowagi. Jako przykład zastosowania rozpatrzono równoczesny pomiar odkształcenia i przyrostu temperatury różnicowym dwuelementowym czujnikiem tensometrycznym. Krótko scharakteryzowano stan prac teoretycznych i wyniki badań eksperymentalnych układów mostków dwuprądowych DC oraz prototypowych konstrukcji przyrządów pomiarowych i stanowisk laboratoryjnych na nich opartych.
The paper discusses the basic relationships and the state of research on a new type of bridge measurement systems with two outputs from both diagonals of a four-arm bridge. Their measuring circuits contain either two current sources or two voltage sources respectively unconventionally connected to opposite branches of these circuits. With direct current (DC), these bridges, after balancing the outputs of each of the diagonals, will enable measurements of two resistances (or two conductances) of their arms. As deflection bridges - they measure simultaneously increments of these resistances from balanced states in diagonals. The formulas for the voltages of both outputs of the systems and the balance conditions for each of them are given. As an example of application, the simultaneous measurement of stress and temperature increase with a differential two-element strain gauge was considered. The current state of theoretical work and the results of several experimental constructions of measuring instruments with a two-current bridge are briefly characterized.
Źródło:
Pomiary Automatyka Robotyka; 2023, 27, 3; 57--65
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of multi-criteria decision making methods for the assessment of optimal SVC location
Autorzy:
Aydin, Faruk
Gümüş, Bilal
Powiązania:
https://bibliotekanauki.pl/articles/2173650.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Borda count method
FACTS
MCDM
optimal location
PSAT
voltage stability
flexible alternating current transmission system
power system analysis toolbox
multi criteria decision making
metoda liczenia Bordy
podejmowanie decyzji wielokryterialnej
lokalizacja optymalna
stabilność napięcia
elastyczne systemy przesyłowe prądu przemiennego
narzędzia do analizy systemu zasilania
Opis:
The goal of multi-criteria decision making (MCDM) is to select the most appropriate of the alternatives by evaluating many conflicting criteria together. MCDM methods are widely available in the literature and have been used in various energy problems. The key problems studied in electrical power systems in recent years have included voltage instability and voltage collapse. Different flexible alternating current transmission systems (FACTS) equipment has been used for this purpose for decades, increasing voltage stability while enhancing system efficiency, reliability and quality of supply, and offering environmental benefits. Finding the best locations for these devices in terms of voltage stability in actual electrical networks poses a serious problem. Many criteria should be considered when determining the most suitable location for the controller. The aim of this paper is to provide a comparative analysis of MCDM techniques to be used for optimal location of a static VAR compensator (SVC) device in terms of voltage stability. The ideal location can be determined by means of sorting according to priority criteria. The proposed approach was carried out using the Power System Analysis Toolbox (PSAT) in MATLAB in the IEEE 14-bus test system. Using ten different MCDM methods, the most appropriate locations were compared among themselves and a single ranking list was obtained, integrated with the Borda count method, which is a data fusion technique. The application results showed that the methods used are consistent among themselves. It was revealed that the integrated model was an appropriate method that could be used for optimal location selection, providing reliable and satisfactory results to power system planners.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 2; art. no. e140555
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the current-voltage characteristics of the photovoltaic cells using the CoachLabII+ measuring console
Wyznaczanie charakterystyk prądowo-napięciowych ogniw fotowoltaicznych z wykorzystaniem konsoli pomiarowej coachlabii+
Autorzy:
Różański, Stanisław Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2200277.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Technologiczno-Humanistyczny im. Kazimierza Pułaskiego w Radomiu
Tematy:
CoachLabII+ console
current-voltage characteristics
maximum power
one-diode model
photovoltaic cell
charakterystyka prądowo-napięciowa
konsola CoachLabII+
moc maksymalna
model jednodiodowy
ogniwo PV
Opis:
The Coach6 software and the CoachLabII+ measuring console coupled with a computer and equipped with appropriate voltage and current sensors were used to determine the current-voltage and power-voltage characteristics of the photovoltaic cells. The current-voltage and power-voltage characteristics for a single cell and cells connected in series and in parallel were tested depending on the light intensity. Using a simplified theoretical model of a photovoltaic cell based on the one-diode equivalent circuit and Shockley diode equation, the ideality factor, diode saturation current and source current were determined, fitting the appropriate theoretical relationship to the measurement results. Based on the current-voltage and power-voltage characteristics, the short-circuit current, open circuit voltage, maximum power, fill factor, conversion efficiency and load resistance were determined. The dependence of the determined parameters on the light intensity was discussed.
Do wyznaczenia charakterystyk prądowo-napięciowych oraz mocowo-napięciowych ogniw fotowoltaicznych wykorzystano oprogramowanie Coach6 oraz konsolę pomiarową CoachLabII+ sprzężoną z komputerem i wyposażoną w odpowiednie czujniki napięcia i prądu. Charakterystyki prądowo-napięciowe dla pojedynczego ogniwa oraz ogniw połączonych szeregowo i równolegle badano w zależności od natężenia światła. Wykorzystując uproszczony model teoretyczny ogniwa fotowoltaicznego bazujący na pojedynczej diodzie oraz wzorze Shockley'a dla prądu diody półprzewodnikowej wyznaczono współczynnik korekcji, prąd wsteczny oraz prąd źródła, dopasowując odpowiednie zależności teoretyczne do wyników pomiarów. Na podstawie charakterystyk prądowo-napięciowych oraz mocowo-napięciowych wyznaczono prąd zwarcia, napięcie obwodu otwartego, moc maksymalną, współczynnik wypełnienia, sprawność konwersji ogniwa oraz rezystancję obciążenia. Zaobserwowano zależność wyznaczonych parametrów od natężenia światła.
Źródło:
Journal of Automation, Electronics and Electrical Engineering; 2022, 4, 2; 31--38
2658-2058
2719-2954
Pojawia się w:
Journal of Automation, Electronics and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical safety in low-voltage DC microgrids with B-type residual current devices
Autorzy:
Czapp, Stanislaw
Tariq, Hanan
Szultka, Seweryn
Szultka, Agata
Zaitseva, Elena
Levashenko, Vitaly
Powiązania:
https://bibliotekanauki.pl/articles/2087019.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
DC microgrids
low-voltage systems
protection against electric shock
reliability
residual current devices
Opis:
Residual current devices (RCDs) are most popular devices used in low-voltage installations for protection against electric shock and fire. In cases of high risk of electric shock the application of RCDs is mandatory. Currently, the spread of local direct current (DC) microgrids is widely considered. This creates new challenges for protective systems, in particular those based on RCDs. The main purpose of the research is to test the operation of B-type RCDs by simulating the conditions that may occur in DC microgrids as well as assessment of the effectiveness of electrical safety with the use of such RCDs. The research has revealed that theoretically identical RCDs in terms of technical data can have different tripping properties, including no reaction to residual direct current, which poses a risk of electric shock. This signalizes the necessity of extension of the normative tests performed by manufacturers. The scope of these additional RCDs tests is indicated, from the point of view of the persons’ safety in DC microgrids.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 2; 346--358
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generating Electricity from Soil Using Different Sources of Manure
Autorzy:
Hassan, Khalida Abdul-Karim
Powiązania:
https://bibliotekanauki.pl/articles/2173274.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
electricity generation
soil
manure
current
voltage
Opis:
In this study three different types of manure (bird, cattle and sheep) with three doses (10, 20 and 30 g) were mixed with soil to investigate and compare the different performance of energy generation as well as provides the ways of increasing the efficiency for such an application. The mixed soil was incubated for ten days after wetting with tap water as needed, then the voltage and current readings were taken every twenty-four hours for ten days. Experiment results indicated that 30 g cattle manure was the best use for energy generating purposes, delivering a voltage peak of 7.4 mV and current of 0.48 mA compared to 7.4 mV; 0.34 mA for bird manure and 6.56 mV; 0.32 mA for sheep manure. Cattle manure produced the highest peak for voltage with all doses and was therefore the best to use. In general, all treatments provide enough voltage to power the LED bulb successfully.
Źródło:
Journal of Ecological Engineering; 2022, 23, 8; 187--192
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigating the protection system of electric motors based on its main working parameters
Autorzy:
Manafov, Elshan
Isgandarov, Islam
Huseynov, Farid
Powiązania:
https://bibliotekanauki.pl/articles/2174836.pdf
Data publikacji:
2022
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
electric motor
short circuit
overload
current sensors
voltage sensor
temperature sensors
relay control
protection system
silnik elektryczny
zwarcie
przeciążenie
czujniki prądu
czujnik napięcia
czujniki temperatury
sterowanie przekaźnikowe
system ochrony
Opis:
This research was devoted to the creation of a protection system for electric motors used in industry and transport, based on modern and traditional sensors. In the course of operation, the malfunctions of electric motors have been investigated and it was found that the accident modes occur mainly due to exceeding the permissible values of the current, voltage and temperature parameters. Modern sensors of current, voltage, and temperature have been compared and the most effective ones were selected for use in electric motors. Based on reasoning from these sensors, a protection system for a low-power electric motor has been developed in the laboratory. In addition, in the Multisim application software package, a simulation of the operation of the protection system at different voltage and current values was performed, and a circuit of the sensor control unit and the power source for powering the protection system was constructed. It has been proposed to apply such a multi-parametric complex protection system for electric motors, especially in transport.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2022, 115; 63--74
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Napięcia i prądy łożyskowe w maszynach elektrycznych
Bearing voltages and currents in electrical machines
Autorzy:
Jarek, Tomasz
Berhausen, Sebastian
Powiązania:
https://bibliotekanauki.pl/articles/2142552.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Tematy:
maszyny elektryczne
napięcie łożyskowe
prąd łożyskowy
electrical machines
bearing voltage
bearing current
Opis:
W artykule przedstawiono podstawowe informacje dotyczące zjawiska napięć i prądów łożyskowych w maszynach elektrycznych. Omówiono podstawowe zagadnienia dotyczące przyczyn występowania zjawisk zarówno w przypadku zasilania maszyny bezpośrednio z sieci jak i przy zasilaniu z przekształtników energoelektronicznych. Zaprezentowano również nowe metody ograniczania napięć łożyskowych bazujące na dodatkowym uzwojeniu pomocniczym nawiniętym wokół jarzma stojana oraz na uzwojeniu ekranującym umieszczonym wewnątrz klinów żłobkowych stojana.
The article presents basic information on the phenomenon of bearing voltages and currents in electrical machines. The basic issues concerning the causes of the described phenomena were discussed, both in the case of powering the machine directly from the AC grid as well as in the case of powering from power electronic converters. New methods of limiting bearing voltages were also presented: based on an additional auxiliary winding wound around the stator yoke and on a shielding winding located inside the stator slot wedges.
Źródło:
Maszyny Elektryczne: zeszyty problemowe; 2022, 3, 1 (127); 169--172
0239-3646
2084-5618
Pojawia się w:
Maszyny Elektryczne: zeszyty problemowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Precision Calculations of the Characteristic Impedance of Complex Coaxial Waveguides Used in Wideband Thermal Converters of AC Voltage and Current
Autorzy:
Kubiczek, Krzysztof
Kampik, Marian
Powiązania:
https://bibliotekanauki.pl/articles/2124756.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AC voltage standard
current shunt
characteristic impedance
multilayer cylindrical conductor
FEM simulation
modified Bessel functions
numerical stability
calorimetric thermal voltage converter
ac-dc transfer difference
Opis:
The article presents precision and numerically stable method of calculation of the characteristic impedance of cylindrical multilayer waveguides used in high-precision wideband measuring instruments and standards, especially calculable thermal converters of AC voltage and precision wideband current shunts. Most of currently existing algorithms of characteristic impedance calculation of such waveguides are based upon approximations. Unfortunately, application of such methods is limited to waveguides composed of a specific, usually low number of layers. The accuracy of approximation methods as well as the number of layers is sometimes not sufficient, especially when the coaxial waveguide is a part of precision measurement equipment. The article presents the numerically stable matrix analytical formula using exponentially scaled modified Bessel functions to compute characteristic impedance and its components of the cylindrical coaxial multilayer waveguides. Results obtained with the developed method were compared with results of simulations made using the Finite Element Method (FEM) software simulations. Very good agreement between results of those two methods were achieved.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 3; 527--533
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review and comparison of methods for limiting leakage currents in single-phase transformerless PV inverter topologies
Autorzy:
Kołodziejski, Wojciech
Jasielski, Jacek
Kuta, Stanisław W.
Szerszeń, Grzegorz
Machowski, Witold
Powiązania:
https://bibliotekanauki.pl/articles/29521110.pdf
Data publikacji:
2022
Wydawca:
Akademia Tarnowska
Tematy:
Differential Mode (DM) voltage
Common Mode (CM) voltage
grid-tied inverter
leakage current
parasitic capacity
photovoltaic (PV) systems
transformerless inverter
napięcie trybu różnicowego (DM).
napięcie trybu wspólnego (CM).
falownik podłączony do sieci
prąd upływowy
pojemność pasożytnicza
systemy fotowoltaiczne (PV).
falownik beztransformatorowy
Opis:
Transformerless inverters are widely used in different photovoltaic nonisolated ac module applications, mainly in grid-tied photovoltaic (PV) generation systems, due to the benefits of achieving high efficiency over a wide load range, and low cost. Various transformerless inverter topologies have been proposed to meet the safety requirement of low ground leakage currents, such as specified in the VDE-4105 standard and low-output ac-current distortion. Topology modifications of transformerless full bridge inverters are designed to balance and maintain a constant common mode output voltage, thereby eliminating or reducing leakage currents. This article reviews and compares the different methods for limiting leakage currents in known topologies of the full-bridge transformerless inverters, such as: H4, H5, H6, HERIC, and their improvements. The main topologies and strategies used to reduce the leakage current in transformerless schemes are summarized, highlighting advantages and disadvantages and establishing points of comparison with similar topologies. To compare the properties of different medium to high power inverters, PV inverter topologies were implemented using IGBTs and tested with the same components, same simulation parameters in PSPICE to evaluate their performance in terms of energy efficiency and leakage current characteristics. The detailed power stage operating principles, extended PWM modulator, and integrated universal gate driver with galvanic isolation in the transmission path of control signal for all IGBTs of the inverter, as well isolated and floating bias power supply for gate drivers are described.
Źródło:
Science, Technology and Innovation; 2022, 16, 3-4; 1-19
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 123

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies