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 "unbalanced" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 35
Tytuł:
Evaluation of the Shunt Active Power Filter apparent power ratio using particle swarm optimization
Autorzy:
Kouzou, A.
Mahmoudi, M. O.
Boucherit, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/229885.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
effective apparent power
shunt active power filter
particle swarm optimization (PSO)
harmonics
unbalanced voltages
unbalanced load
Opis:
The main objective of this present paper is the study of the Shunt Active Power Filter (APF) compensations capability for different perturbations in AC power system such as current unbalance, phase shift current and undesired harmonics generated by nonlinear load and/or by the power system voltage. This capability is determined by the maximum rate of the apparent power that can be delivered. This study is based on the definition of the effective apparent power as defined in IEEE 1459-2000 which was proved to be the suitable amount to be concerned in the design process of different devices.
Źródło:
Archives of Control Sciences; 2010, 20, 1; 47-76
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cogging torque and torque ripple analysis of permanent magnet flux-switching machine having two stators
Autorzy:
Awah, Chukwuemeka Chijioke
Okoro, Ogbonnaya Inya
Chikuni, Edward
Powiązania:
https://bibliotekanauki.pl/articles/140414.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cogging torque
torque ripple
separate stators
unbalanced magnetic force
Opis:
The analysis of cogging torque, torque ripple and total harmonic distortion of a permanent magnet (PM) flux-switching machine having separate excitation stators is presented in this study. Further, the effect of unbalanced magnetic force (UMF) on the rotor of this machine is also investigated. A comparison of the analysed machine having different rotor pole configurations is also given. The analysis shows that the largest cogging torque, torque ripple as well as total harmonic distortion (THD) are obtained in the four-rotor-pole machine while the least of THD and torque ripple effects is seen in the thirteen-rotor-pole machine. Furthermore, the evaluation of the radial magnetic force of the machines having an odd number of rotor poles shows that the investigated machine having a five-rotor-pole number exhibits the highest value of UMF, while the smallest amount of UMF is obtained in an eleven-rotor-pole machine. Similarly, it is observed that the machines having an even number of rotor poles exhibit a negligible amount of UMF compared to the ones of the odd number of rotor poles.
Źródło:
Archives of Electrical Engineering; 2019, 68, 1; 115-133
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isotropic and anisotropic double-phase problems: old and new
Autorzy:
Radulescu, Vicentiu D.
Powiązania:
https://bibliotekanauki.pl/articles/255323.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
differential operator with unbalanced growth
double-phase energy
variable exponent
Opis:
We are concerned with the study of two classes of nonlinear problems driven by differential operators with unbalanced growth, which generalize the (p, q)- and (p(x),q(x))-Laplace operators. The associated energy is a double-phase functional, either isotropic or anisotropic. The content of this paper is in relationship with pioneering contributions due to P. Marcelimi and G. Mingione.
Źródło:
Opuscula Mathematica; 2019, 39, 2; 259-279
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inverting covariance matrices
Autorzy:
Stępniak, Czesław
Powiązania:
https://bibliotekanauki.pl/articles/729982.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
multi-way classification
cross
hierarchical
balanced
unbalanced
covariance matrix
inverting
Opis:
Some useful tools in modelling linear experiments with general multi-way classification of the random effects and some convenient forms of the covariance matrix and its inverse are presented. Moreover, the Sherman-Morrison-Woodbury formula is applied for inverting the covariance matrix in such experiments.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2006, 26, 2; 163-177
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and numerical analysis of a highly sensitive ultrasonic acoustic sensor based on π-phase-shifted fiber Bragg grating and fiber Mach-Zehnder interferometer interrogation
Autorzy:
Dwivedi, Krishna Mohan
Trivedi, Gaurav
Khijwania, Sunil K.
Osuch, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/220964.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
π-FBG
unbalanced F-MZI
strain sensitivity
ultrasonic acoustic sensor
Opis:
A π-phase-shifted fiber Bragg grating (π-FBG) shows high sensitivity to the ultrasonic (US) wave as compared to the conventional FBG due to the strong slow-light phenomenon at the resonance peak. However, its sensitivity is limited by the interrogation schemes. A combination of π-FBG and unbalanced fiber Mach-Zehnder interferometer (F-MZI) are theoretically analyzed and optimized for the highly sensitive acoustic sensor. The coupled-mode theory (CMT) and transfer matrix method (TMM) are used to establish the numerical modelling of π-FBG. For the optimized grating parameters of π-FBG, the proposed sensing system shows the high strain sensitivity of 1.2x108/ε, the highest dynamic strain resolution of 4.1fε/√Hz, and the highest wavelength shift resolution of 4.9x10-9 pm. Further, the proposed sensing system strongly supports both time and wavelength division multiplexing techniques. Therefore, the proposed sensing system shows extreme importance in single as well as quasi-distributed US acoustic wave sensing networks.
Źródło:
Metrology and Measurement Systems; 2020, 27, 2; 289-300
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of a doubly fed induction generator at grid voltage imbalance
Autorzy:
Łuszczyk, T.
Iwański, G.
Powiązania:
https://bibliotekanauki.pl/articles/1193415.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
doubly fed induction generator
power control
torque control
unbalanced grid
Opis:
Properties and control of a doubly fed induction machine operating under unbalanced grid voltage conditions have been presented. The proposed method does not include symmetrical sequences decomposition and is realized in a rotating frame not synchronized either with the grid voltage vector or with the stator flux vector. The method uses a reference torque and the reference q component of instantaneous power for calculation of the reference stator current. Next, calculation of magnetizing current for a given unbalanced grid voltage is used to assign the reference rotor current. Due to the fact that the reference current contains both a positive and a negative sequence, a proportional-integral-resonant controller is used. The main control target is the non-oscillatory waveform of torque, whereas other separate strategies like symmetrical stator current or sinusoidal rotor current can be easily obtained by adequate filtration of the reference control signals of the stator or rotor currents, respectively. The simulation results of the 2 MW model have been presented for a doubly fed induction generator as well as the results of laboratory tests with the use of a small scale 7.5 kW machine.
Źródło:
Power Electronics and Drives; 2017, 2, 37/2; 31-48
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
HVDC auxiliary emergency power control strategy for power disturbance in two different positions of AC/DC interconnection system
Autorzy:
Li, Congshan
He, Ping
Wang, Youyi
Ji, Yuyi
Yang, Cunxiang
Powiązania:
https://bibliotekanauki.pl/articles/141502.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
unbalanced power
emergency control
power angle stability
frequency stability
control logic
Opis:
High voltage direct current (HVDC) emergency control can significantly improve the transient stability of an AC/DC interconnected power grid, and is an important measure to reduce the amount of generator and load shedding when the system fails. For the AC/DC interconnected power grid, according to the location of failure, disturbances can be classified into two categories: 1) interconnected system tie-line faults, which will cause the power unbalance at both ends of the AC system, as a result of the generator rotor acceleration at the sending-end grid and the generator rotor deceleration at the receiving-end grid; 2) AC system internal faults, due to the isolation effect of the DC system, only the rotor of the generator in the disturbed area changes, which has little impact on the other end of the grid. In view of the above two different locations of disturbance, auxiliary power and frequency combination control as well as a switch strategy, are proposed in this paper. A four-machine two-area transmission system and a multi-machine AC/DC parallel transmission system were built on the PSCAD platform. The simulation results verify the effectiveness of the proposed control strategy.
Źródło:
Archives of Electrical Engineering; 2019, 68, 2; 245-263
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
UNBALANCED DISTRIBUTION OF FOOD
Autorzy:
Sarikaya, Buse
Powiązania:
https://bibliotekanauki.pl/articles/1036580.pdf
Data publikacji:
2017-11-14
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
food distribution
unbalanced nutrition
common nutritional problems in Society
malnutrition
obesity
Opis:
While people starve every day, food is being wasted. Simultaneously a food shortage does not exist on our planet. There is no lack of food. Production and distribution are the two primary causes of this problem. Unbalanced nutrition is the cause of obesity, overweight and hunger. Insufficient food intake causes nutritional problems such as vitamin and Iodine deficiency, Anaemia, Underweight and Stunting, Low birth weight, Protein-Energy Malnutrition, excess intake of food causes. However, nutritional health problems are not only caused by the absense of food but also from excessive food intake causing diabetes, hypertension, heart diseases etc. These all health problems effect societies worldwide. Bringing the global burden of diet-related noncomunicable diseases under control and enhancing public nutrition and health requires a muti-diciplinary approach.
Źródło:
Society Register; 2017, 1, 1; 199-208
2544-5502
Pojawia się w:
Society Register
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Currents Physical Components (CPC) in Circuits with Nonsinusoidal Voltages and Currents. Part 2: Three-Phase Three-Wire Linear Circuits
Autorzy:
Czarnecki, L. S.
Powiązania:
https://bibliotekanauki.pl/articles/262598.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
power definition
power phenomena
apparent
reactive
scattered
unbalanced currents or powers
Opis:
This paper summarizes the present state of discussions on power phenomena, power definitions and compensation in three-phase three-wire linear circuits with nonsinusoidal voltages and currents. In particular, definitions of the arithmetic and geometric apparent powers are discussed. It is shown that these two powers result in an erroneous value of power factor of unbalanced loads even if voltages and currents are sinusoidal. A reasoning that leads to a right selection of the apparent power definition is presented as well. The paper also presents the con-cept of the three-phase current decomposition into Currents' Physical Components (CPC) and its application for power definitions and compensation in three-phase circuits.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 1; 3-13
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Praca układu wzbudzenia i regulacji napięcia generatora synchronicznego w stanach niesymetrycznych
The operation of the excitation and voltage control system of a synchronous generator in asymmetrical states
Autorzy:
Madajewski, K.
Rink, R.
Powiązania:
https://bibliotekanauki.pl/articles/397316.pdf
Data publikacji:
2011
Wydawca:
ENERGA
Tematy:
generator synchroniczny
stany niesymetryczne
regulacja napięcia
synchronous generator
unbalanced states
voltage regulation
Opis:
Artykuł dotyczy analizy pracy statycznego tyrystorowego układu wzbudzenia i regulacji napięcia generatora synchronicznego dużej mocy w niesymetrycznych stanach pracy. Analizowane niesymetrie są m.in. wynikiem zwarć niesymetrycznych w systemie elektroenergetycznym (SEE). Przedstawione wyniki badań uzyskano z modelu symulacyjnego, odwzorowującego chwilowe przebiegi czasowe w obwodach wzbudzenia i regulacji napięcia oraz w SEE. Model generatora synchronicznego uwzględnia składowe transformacji. Model prostownika wzbudzenia nie opisuje charakterystyki zewnętrznej prostownika z wykorzystaniem napięć średnich, jak to ma miejsce zazwyczaj, ale jest modelem opisującym napięcia chwilowe na wyjściu trójfazowego sześciopulsowego prostownika. Prąd wzbudzenia generatora steruje w modelu źródłem prądowym wymuszającym prąd w prostowniku i transformatorze wzbudzenia. Model SEE uwzględnia impedancje zastępczej linii dla składowych symetrycznych. Sygnały wejściowe do modelu regulatora napięcia nie są wyprowadzane z modelu generatora, ale są wyznaczane z wykorzystaniem pomiarów z przekładników napięciowych i prądowych, a następnie cyfrowo przetwarzane w celu obliczenia użytecznych sygnałów sterujących. Model umożliwia szczegółowe analizowanie niesymetrycznych i zakłóconych stanów pracy generatora z układem wzbudzenia i regulacji napięcia. Jest on również niezbędny do analizy nowych rozwiązań w cyfrowych układach regulacji napięcia.
This paper concerns the analysis of performance of static thyristor excitation and voltage regulation control systems of a high-power synchronous generator in asymmetrical operating states. Presented results were obtained from the model that reflects instantaneous processes both in the grid and in the excitation and voltage control system. The model of the synchronous generator includes the components of transformation. The rectifier model is based on a detailed thyristor model in the circuit of three-phase six-pulse thyristor converter, instead of simplified block model with defined external characteristics, as it is usual. It enables to monitor instantaneous values of rectifier voltages. The input signals for the voltage regulator model are not derived from the generator model the control system model includes digital measurement units of generator signals. The described model enables precise analysis of a synchronous generator with an excitation and voltage control system during disturbances and asymmetric operation in the grid. Such modelling is essential for analysis of novel solutions of excitation systems with digital controllers. This kind of analysis is not feasible using simplified models based on mean signals values and external characteristics of excitation systems.
Źródło:
Acta Energetica; 2011, 2; 23-30
2300-3022
Pojawia się w:
Acta Energetica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przetwornik z modulacją kwadraturową do pomiaru parametrów wiatru
Transducer with quadrature modulation for measurements of wind parameters
Autorzy:
Rylski, A.
Powiązania:
https://bibliotekanauki.pl/articles/157100.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sensory
tensometry
modulacja kwadraturowa
mostki niezrównoważone
sensors
strain gauge
quadrature modulation
unbalanced bridge
Opis:
W artykule opisano kształt belki przetwornika tensometrycznego charakteryzującego się stałym współczynnikiem ugięcia w funkcji zmian prędkości wiatru oraz zaproponowano mostkową modulację kwadraturową do jednoczesnego pomiaru dwóch parametrów wiatru: prędkości i kierunku. Ta konstrukcja nie posiada elementów ruchomych i jest niewrażliwa na zmiany temperatury i wilgotności powietrza.
The paper presents the shape of a strain gauge transducer beam which is characterized by a constant deflection coefficient at wind speed changes. The bridge quadrature modulation is proposed for simultaneous measurements of the wind intensity and direction. The presented construction has no movable elements and is insensitive to changes in air temperature and humidity.
Źródło:
Pomiary Automatyka Kontrola; 2008, R. 54, nr 12, 12; 857-859
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational investigation of vibration characteristics analysis for industrial rotor
Autorzy:
Aimeur, Noureddine
Menasri, Noureddine
Powiązania:
https://bibliotekanauki.pl/articles/2204679.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
rotor dynamic
finite element method
reverse design
CMM
unbalanced
blade wear
simulation
ANSYS
Opis:
During the operation of a rotor, various types of vibrations appear in this mechanical system and often limit the performance and endanger the safety of the operation. Therefore, dynamic analysis is essential because precise knowledge of the vibration behaviour is essential to ensure proper operation. This article presents a set of scientific techniques for the modelling and simulation of rotor vibrations. To work out the equations of the vibratory movement of the rotor, we used the energy approach of Lagrange. To achieve this, a model with one blading wheel carried by a shaft supported by two hydrodynamic bearings is chosen basedon the characteristics of the rotor studied (Fan 280 cement draft fan). It is an arduous task to manually ascertain the analytical resolution of the differential equations that characterise the vibratory behaviour of the rotor. The numerical approach employing the finite element method, programmed on the ANSYS software, made it possible to perform the vibration analysis of the rotor. First, the FAN 280 cement draft fan rotor is modelled using SolidWorks 3D software and reverse design using the coordinate measuring machine (CMM) for the design of the fins. Then, the modal characteristics of the fan rotor model were analysed using the finite element analysis (FEA) software ANSYS Workbench. Also, to study the effect of blade wear on critical speeds, the Campbell diagram was obtained. Finally, harmonic analysis was performed to determine the amplitude of the rotor vortex at critical speeds obtained with and without blade wear.
Źródło:
Acta Mechanica et Automatica; 2022, 16, 4; 373--381
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kompensacja wpływu zmiany temperatury na pracę sensorów w mostkowym modulatorze kwadraturowym
Compensation of temperature effect on sensor operation used in
Autorzy:
Rylski, A.
Powiązania:
https://bibliotekanauki.pl/articles/155056.pdf
Data publikacji:
2006
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
mostek niezrównoważony
kompensacja temperaturowa
modulacja kwadraturowa
unbalanced bridge
compensation of temperature effect
Quadrature Modulator
Opis:
W artykule opisano kompensację wpływu zmiany temperatury sensorów na ich sygnał w układach modulacji kwadraturowej z mostkiem Wiena do jednoczesnego pomiaru sygnałów z dwóch czujników rezystancyjnych.
The possibility compensation of temperature effect on sensor signals in Wiena bridge Quadrature Modulator used for simultaneous measurement of signal from two resistance sensors is presented.
Źródło:
Pomiary Automatyka Kontrola; 2006, R. 52, nr 12, 12; 30-33
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis on electromechanical coupling vibration characteristics of in-wheel motor in electric vehicles considering air gap eccentricity
Autorzy:
Li, Y.
Wu, H.
Xu, X.
Cai, Y.
Sun, X.
Powiązania:
https://bibliotekanauki.pl/articles/200165.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
BLDC in-wheel motor
rotor eccentricity
unbalanced magnetic force
electric vehicle
electromechanical coupling vibrat
Opis:
The distortion of air gap magnetic field caused by the rotor eccentricity contributes to the electromechanical coupling vibration of the brushless DC (BLDC) permanent magnet in-wheel motor (PMIWM) in electric vehicles (EV). The comfort of the BLDC in-wheel motor drive (IWMD) EV is seriously affected. To deeply investigate the electromechanical coupling vibration of the PMIWM under air gap eccentricity, the PMIWM, tyre and road excitation are analyzed first. The influence of air gap eccentricity on air gap magnetic density is investigated. The coupling law of the air gap and the unbalanced magnetic force (UMF) is studied. The coupling characteristics of eccentricity rate, air gap magnetic density, UMF, phase current and vibration acceleration are verified on the test bench in the laboratory. The mechanism of the electro-mechanical coupling vibration of the BLDC PMIWM under air gap static eccentricity (SE), dynamic eccentricity (DE) and hybrid eccentricity (HE) is revealed. DE and HE deteriorate the vibration acceleration amplitude, which contributes the electromechanical coupling vibration of the PMIWM. The research results provide a solid foundation for the vibration and noise suppression of the PMIWM in distributed drive EV.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 5; 851-862
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of confidence intervals for variance components in an unbalanced one-way random effects model
Autorzy:
Jiratampradab, Arisa
Supapakorn, Thidaporn
Suntornchost, Jiraphan
Powiązania:
https://bibliotekanauki.pl/articles/2156992.pdf
Data publikacji:
2022-12-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
variance components
unbalanced one-way random effects model
pivotal quantity
fiducial inference
coverage probability
Opis:
The purpose of this paper is to study and compare the methods for constructing confidence intervals for variance components in an unbalanced one-way random effects model. The methods are based on a classical exact, generalised pivotal quantity, a fiducial inference and a fiducial generalised pivotal quantity. The comparison of criteria involves the empirical coverage probability that maintains at the nominal confidence level of 0.95 and the shortest average length of the confidence interval. The simulation results show that the method based on the generalised pivotal quantity and the fiducial inference perform very well in terms of both the empirical coverage probability and the average length of the confidence interval. The classical exact method performs well in some situations, while the fiducial generalised pivotal quantity performs well in a very unbalanced design. Therefore, the method based on the generalised pivotal quantity is recommended for all situations.
Źródło:
Statistics in Transition new series; 2022, 23, 4; 149-160
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 35

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