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Wyszukujesz frazę "Current" wg kryterium: Temat


Tytuł:
Multiple output CMOS current amplifier
Autorzy:
Pankiewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/201141.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current amplifier
current follower
current mirror
CMOS technology
wzmacniacz prądowy
prąd
technologia CMOS
Opis:
In 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 examples, a current amplifier and bandpass biquad section designed in CMOS TSMC 90nm technology are presented. The current amplifier is powered from a 1.2V supply. MOS transistors scaling was chosen to obtain output gains equal to -2, 1 and 2. Simulated real gains are -1.941, 0.966 and 1.932 respectively. The 3dB passband obtained is above 20MHz, while current consumption is independent of input and output currents and is only 7.77μA. The bandpass biquad section utilises the previously presented amplifier, two capacitors and one resistor, and has a Q factor equal to 4 and pole frequency equal to 100 kHz.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 2; 301-306
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the inductive current transformer derating for operation with distorted currents
Autorzy:
Kaczmarek, M.
Powiązania:
https://bibliotekanauki.pl/articles/201060.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current transformer
distorted current
derating conditions
composite errors
transformer correction factor
accuracy class
Opis:
The aim of the paper is to present a new method for estimation of the CT (Current Transformer) rated primary current and / or load of the secondary winding derating levels for transformation of distorted current in relation to the rated values fixed for transformation of sinusoidal current. This ensures the values of the CT composite errors/transformer correction factors as resulting from its IEC 60044-1/IEEE C57.13 accuracy class in condition of distorted currents transformation.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 2; 363-366
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current mode sigma-delta modulator designed with the help of transistor’s size optimization tool
Autorzy:
Śniatała, P.
Naumowicz, M.
Handkiewicz, A.
Szczęsny, S.
Melo, J. L. A.
Paulino, N.
Goes, J.
Powiązania:
https://bibliotekanauki.pl/articles/201254.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sigma-delta
current comparator
CAE
komparator
Opis:
The paper presents a second order current mode sigma-delta modulator designed with the help of a new elaborated tool to optimize the transistor sizes. The circuit is composed of two continuous time loop filters, a current comparator and a one bit DAC with a current output. The resulting circuit, designed in a 65 nm 1.2 V CMOS technology, has a bandwidth of 2 MHz for a clock frequency of 250 MHz. The electrical simulation results show that it achieves a maximum signal-to-noise-plus-distortion ratio (SNDR) of 53.6 dB while dissipating 93 μW, which corresponds to an efficiency of 59.7 fJ/conv. The fully current mode structure makes the circuit suitable to be applied in a current mode signal processing like biosensors or image pixels arrays.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 4; 919-922
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified current differencing transconductance amplifier - new versatile active element
Autorzy:
Malcher, A.
Powiązania:
https://bibliotekanauki.pl/articles/201665.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current differencing transconductance amplifier
quadrature oscillator
amplitude regulation
current-mode operational amplifier
continuous time field programmable analog array
Opis:
This paper introduces a new current mode component called Modified Current Differencing Transconductance Amplifier (MCDTA). Important parameters of the circuit i.e. input resistance, z terminal resistance and transconductance of the output stage can be tuned electrically. The circuit can be implemented in linear and non-linear analog signal processing. The paper presents an example of the MCDTA application - a complete quadrature oscillator with the amplitude regulation. The functionality of the example circuit and its tuning capability were proved by the SPICE simulation results.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 4; 739-750
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical fibre current sensor for electrical power engineering
Autorzy:
Barczak, K.
Powiązania:
https://bibliotekanauki.pl/articles/200123.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetooptic effect
optical fiber current sensors
polarimetric sensors
Opis:
The paper presents the experimental results of the investigations of optical fibre current sensors with an external transformation. The head of the sensor is made of the glass which has a high value of the Verdet constant. The sensor was built on the glass bar (with high value of the Verdet coefficient), polarisers, plastic optical fibres, a light source and a detector module. The paper deals with magnetic field measurements of two types of electrical current conductors: a typical conductor with circular cross-section and a busduct. Output signals from the optical current sensor were displayed on the digital oscilloscope and memorized in ěComp for a further analysis. This type of sensor was investigated on a laboratory stand and on an electrical power line which included conductor where the high intensity electric current flow. The constructed optoelectronic current sensor was tested for detection of current with intensity of the order of 200 A, with an accuracy of a few percent. Practically, the upper border of the current detection by means of this sensor is much higher.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 4; 409-414
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A predictive estimation based control strategy for a quasi-resonant dc-link inverter
Autorzy:
Turzyński, M.
Banach, P.
Murawski, P.
Pepliński, R.
Chrzan, P. J.
Powiązania:
https://bibliotekanauki.pl/articles/200484.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
resonant converters
ZVS three-phase inverter
current estimation
Opis:
Control of parallel quasi resonant dc link inverters (PQRDCLI) is usually based on dc link input inverter current. Instead of a direct measurement of this noise sensitive and fast changing current signal - its estimation with one step prediction may be considered. Estimation of an input inverter current is based on inverter output current measurements, applied in most of power electronics controlled ac drives. In this paper, the PQRDCLI fed induction motor (IM) with a predictive current estimation stabilizes resonant inverter output voltage slopes du/dt independently of load. By control of output voltage derivatives, reduction of overvoltage spikes and common mode motor currents is achieved. An analysis of the PQRDCLI control with a predictive current estimation strategy is verified by the Saber system simulation and experimental tests in a laboratory setup.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 757-762
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of optimal current in the non-ideal one-phase system with unsteady parameters
Autorzy:
Dębowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/200279.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuzzy numbers
optimisation
minimisation of power losses
optimal current
Opis:
Some of parameters in electrical systems cannot be considered as constants. In particular, some electrical loads should be described as unsteady because of physical reasons, e.g. arc and arc-resistance furnaces. One of the method to describe parameters of such loads is description by fuzzy numbers. Moreover, this description enables to determine optimal current of the system with unsteady parameters by an application of the optimisation technique called as fuzzy mathematical programming. The optimisation problem has been presented for one-phase system with sinusoidal waveforms. The obtained solution (optimal current) can be determined as crisp one (real numbers) in frequency domain in the numerical way. The determined optimal current has minimal RMS value in this case when the power constraints do not have to be fulfilled strictly because of changes of system parameters. It means simultaneously the minimisation of power losses in the system. This solution generalizes the classical optimisation solution obtained for the systems with constant parameters. In order to illustrate the problem the appropriate example has been presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 2; 387-391
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vector analysis of the current commutation in PM BLDC drives
Autorzy:
Buja, G.
Menis, R.
Keshri, R.
Powiązania:
https://bibliotekanauki.pl/articles/201920.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PM BLDC drive
current commutation
stationary plane vector analysis
Opis:
The vector approach in either stationary or synchronous plane is commonly used for the analysis of the AC drives like induction and PM brushless AC drives whilst it has been hardly ever used for the PM brushless DC (BLDC) drives. A possible reason is that they require injection of square-wave currents into the motor phases, which are non-sinusoidal in nature. Recently, the PM BLDC drives have been analyzed by the help of the vector approach in the stationary plane. This paper applies such an approach to an in-depth analysis of the operation of the PM BLDC drives during the current commutations, illustrating the potentialities of the approach in giving a better insight into the current transients and the ensuing torque characteristics. At last, two voltage control strategies proposed to eliminate the torque ripple due to the current commutations are considered, showing that they can be readily understood by the vector approach.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 829-836
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical fault detection in rotating electrical machines using MCSA-FFT and MCSA-DWT techniques
Autorzy:
Bessous, N.
Sbaa, S.
Megherbi, A. C.
Powiązania:
https://bibliotekanauki.pl/articles/200283.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
motor current signature analysis
MCSA
discrete wavelet transform
DWT
rolling element bearing faults
rotor eccentricity
stator current spectrum
dyskretna transformata falkowa
uszkodzenia łożysk tocznych
widmo prądu stojana
Opis:
This paper presents mechanical fault detection in squirrel cage induction motors (SCIMs) by means of two recent techniques. More precisely, we have analyzed the rolling element bearing (REB) faults in SCIM. Rolling element bearing faults constitute a major problem among different faults which cause catastrophic damage to rotating machinery. Thus early detection of REB faults in SCIMs is of crucial importance. Vibration analysis is among the key concepts for mechanical vibrations of rotating electrical machines. Today, there is massive competition between researchers in the diagnosis field. They all have as their aim to replace the vibration analysis technique. Among them, stator current analysis has become one of the most important subjects in the fault detection field. Motor current signature analysis (MCSA) has become popular for detection and localization of numerous faults. It is generally based on fast Fourier transform (FFT) of the stator current signal. We have detailed the analysis by means of MCSA-FFT, which is based on the stator current spectrum. Another goal in this work is the use of the discrete wavelet transform (DWT) technique in order to detect REB faults. In addition, a new indicator based on the MCSA-DWT technique has been developed in this study. This new indicator has the advantage of expressing itself in the quantity and quality form. The acquisition data are presented and a comparative study is carried out between these recent techniques in order to ensure a final decision. The proposed subject is examined experimentally using a 3 kW squirrel cage induction motor test bed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 3; 571-582
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A switched reluctance motor control method limiting the maximum dc source current in the low-speed range
Autorzy:
Bogusz, P.
Powiązania:
https://bibliotekanauki.pl/articles/202443.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
switched reluctance motor
current control
electric vehicle
silnik
regulacja prądu
pojazd elektryczny
Opis:
This paper presents a proposal of a new control method of the switched reluctance motor (SRM) in the low-speed range. The proposed method limits the maximum value of SRM drive supply current. The application of this method results also in improvement of the drive efficiency compared to the classical current control method, so it can be applied to control switched reluctance motors designed to the electric vehicles drive. The method may be effective especially in congested traffic. Nowadays, the urban traffic is characterized by frequent occurrence of traffic jams in which cars move at low speeds. The sources of supply for electric vehicles are mainly electrochemical batteries. Reduction of the maximum value of supply current allows to extend the service life of batteries and improvement of the drive efficiency extends the vehicle range.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 1; 197-206
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low power 9-bit pipelined A/D and 8-bit self-calibrated D/A converters for a DSP system
Autorzy:
Wawryn, K.
Suszynski, R.
Powiązania:
https://bibliotekanauki.pl/articles/199995.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current mode circuits
pipelined a/d converter
self-calibrating d/a converter
Opis:
A low power, low voltage current mode 9 bit pipelined a/d converter and 8 bit self-calibrated d/a converter to interface a DSP system are presented in the paper. The a/d converter is built of 1.5 bit stages with digital error correction logic. The d/a converter is composed of 3 LSBs fine and 5 MSBs coarse current mode converters. The a/d and d/a converters were designed in 0.35 μm technology, then fabricated to verify the proposed concept. The performances of both converters are compared to the performances of known converter structures. The main advantages of the proposed converters are low power consumption and small chip area.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 979-988
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty of the characteristics of electrical devices based on the measurements of time-current characteristics of MV fuses
Autorzy:
Daszczyński, T.
Pochanke, Z.
Kolimas, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/200192.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
time-current characteristic
MV fuse
approximation of measurement results
fuse element
statistics
Opis:
Functional properties of some electrical devices are expressed in the form of a dependence between parameters defining a given aspect of device duty or work circumstance (e.g. breakdown voltage): contacts distance for a circuit breaker, current (voltage for voltage limiters or reaction time), and load current for over current protection. Such characteristics are obtained experimentally, usually in a set of test series, each performed with a fixed independent parameter. Results of each series generate sets of data for estimation of statistical properties of a dependent parameter: distribution, expected value, variance and confidence interval. These statistics concern one point of the tested characteristic, so to get data of it as a whole, that would satisfy the needs for designing an electrical system, a large number of tests can be necessary. The way to reduce the number of tests may consists in: defining the characteristic not as a series of points, but as an analytical function with some specific parameters. This can be combined with aggregation of results of all tests in one set of data for estimation of statistical properties of the mantioned parameter. This paper presents an application of the above approach to tests of time-current characteristics of fuses.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 751-757
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the stator current reconstruction method on direct torque control of induction motor drive in current sensor postfault operation
Autorzy:
Adamczyk, Michal
Orlowska-Kowalska, Teresa
Powiązania:
https://bibliotekanauki.pl/articles/2173546.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current sensor fault
induction motor drive
direct torque control
DTC
current estimator
fault-tolerant control
usterka czujnika
napęd silnika indukcyjnego
bezpośrednia kontrola momentu obrotowego
estymator
kontrola odporna na awarie
Opis:
Modern induction motor (IM) drives with a higher degree of safety should be equipped with fault-tolerant control (FTC) solutions. Current sensor (CS) failures constitute a serious problem in systems using vector control strategies for IMs because these methods require state variable reconstruction, which is usually based on the IM mathematical model and stator current measurement. This article presents an analysis of the operation of the direct torque control (DTC) for IM drive with stator current reconstruction after CSs damage. These reconstructed currents are used for the stator flux and electromagnetic torque estimation in the DTC with space-vector-modulation (SVM) drive. In this research complete damage to both stator CSs is assumed, and the stator current vector components in the postfault mode are reconstructed based on the DC link voltage of the voltage source inverter (VSI) and angular rotor speed measurements using the so-called virtual current sensor (VCS), based on the IM mathematical model. Numerous simulation and experimental tests results illustrate the behavior of the drive system in different operating conditions. The correctness of the stator current reconstruction is also analyzed taking into account motor parameter uncertainties, especially stator and rotor resistances, which usually are the main parameters that determine the proper operation of the stator flux and torque estimation in the DTC control structure.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 1; e140099, 1--11
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance evaluation of ZVS/ZCS high efficiency AC/DC converter for high power applications
Autorzy:
Ali, A.
Chuanwen, J.
Khan, M. M.
Habib, S.
Ali, Y.
Powiązania:
https://bibliotekanauki.pl/articles/200472.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
switching losses
zero current switching
zero voltage switching
power quality
reverse recovery loss
Opis:
The increased power density, reduced switching losses with minimum electromagnetic interference (EMI), and high efficiency are essential requirements of power converters. To achieve these characteristics, soft power converters employing soft switching techniques are indispensable. In this paper, a ZCS/ZVS PWM AC/DC converter topology has been emphasized, which finds applications in high power systems such as automobile battery charging and renewable energy systems. This converter scheme maintains zero current and zero voltage switching conditions at turn on and turn off moments of semiconductor switches, respectively and soft operation of rectifier diodes that lead to negligible switching and diode reverse recovery losses. Moreover, it improves power quality and presents high input power factor, low total harmonic distortion of the input current (THDI ) and improved efficiency. The validity of theoretical analysis of the proposed converter has been carried out experimentally on a 10 kW laboratory prototype. Experimental results prove that the soft switching operation of the semiconductor switches and diodes is maintained at 98.6% rated load efficiency. In addition, the performance evaluation has been performed by comparative analysis of the proposed converter with some prior art high power AC/DC converters. Efficiencies of the proposed and prior art high power topologies have been determined for different load conditions. The highest efficiency, power factor and lower THDI of the proposed converter topology complies with international standards.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 793-807
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reactive compensator synthesis in time-domain
Autorzy:
Siwczyński, M.
Jaraczewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/201083.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power and energy theory
reactive power filters
reactive current
optimization
harmonic filter design
Opis:
The source reactive-current compensation is crucial in the energy transmission efficiency. The compensator design in a frequencydomain has already been widely discussed and examined. This paper presents results of a study on how to design reactive compensators in a time-domain. It is the first time the reactive compensator has been designed in a time domain. The example of a compensator is presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 1; 119-124
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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