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Wyszukujesz frazę "modulation" wg kryterium: Temat


Tytuł:
Resource allocation in MIMO systems specific to radio communication
Autorzy:
Ghaderi, Bahar
Parhizgar, Naser
Powiązania:
https://bibliotekanauki.pl/articles/140794.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spatial modulation
multi quadrature amplitude modulation
modulation
Huffman coding
MIMO systems
Opis:
The performance of the multi-input multi-output (MIMO) systems can be improved by spatial modulation. By using spatial modulation, the transmitter can select the best transmit antenna based on the channel variations using channel state information (CSI). Also, the modulation helps the transmitter to select the best modulation level such that the system has the best performance in all situations. Hence, in this paper, two issues are considered including spatial modulation and information modulation selection. For the spatial modulation, an optimal solution for obtaining the probability of selecting antenna is calculated and then Huffman coding is used such that the transmitter can select the best transmit antenna to maximize the channel capacity. For the information modulation, a multi quadrature amplitude modulation (MQAM) strategy is used. In this modulation, the modulation size is changed based on the channel state variations; therefore, the best modulation index is used for transmitting data in all channel situations. In simulation results, the optimal method is compared with Huffman mapping. In addition, the effect of modulation on channel capacity and a bit error rate (BER) is shown.
Źródło:
Archives of Electrical Engineering; 2019, 68, 1; 91-100
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved space vector modulation strategy for common-mode voltage reduction in matrix rectifier
Autorzy:
Liu, X.
Zhang, Q.
Hou, D.
Powiązania:
https://bibliotekanauki.pl/articles/950664.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
matrix converter
space vector modulation
common-mode voltage
Opis:
The matrix rectifier modulated by the classical space vector modulation (SVM) strategy generates common-mode voltage (CMV). The high magnitude and high du/dt of the CMV causes serious problems such as motor damage, electromagnetic noise and many others. In this paper, an improved SVM strategy is proposed by replacing the zero vectors with suitable couple of active ones that substantially eliminate the CMV. Theoretical analysis proves that the proposed strategy can reduce the amplitude of the CMV to half of the original value. In addition, the quality of the input and output waveforms is not affected by extra active vectors. Simulation and experimental results demonstrate the feasibility and effectiveness of the proposed strategy are shown.
Źródło:
Archives of Electrical Engineering; 2014, 63, 1; 93-106
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and simulation of novel stepped DC coupled quasi Z-Multilevel Inverter for single phase systems
Autorzy:
Meenakshi, T.
Suthanthira Vanitha, N.
Powiązania:
https://bibliotekanauki.pl/articles/140968.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multilevel inverter
shoot through
quasi Z-Source
modulation index
Opis:
This paper presents the modeling and simulation of a novel topology of quasi Z-Multilevel Inverter with stepped DC input. The proposed inverter incorporates a simple switching technique with reduced component count and is aimed at producing boosted multilevel output AC voltage. The inverter consists of two stages and the buck /boost operation is obtained by varying the shoot through period of the pulses obtained by maximum constant boost control with third harmonic injection. With all the advantages of the quasi Z-network, the proposed inverter eliminates the fly back diodes and capacitors present in a conventional Z-Multilevel Inverter. Further the stress on the devices is less which leads to reduction in component value and hence the cost. The novel stepped DC coupled Single Phase quasi Z-Multilevel Inverter is modeled and simulated in the MATLAB – SIMULINK environment and its performance is analyzed for varying input and switching conditions. The voltage and current waveforms across each stage of the inverter is analyzed and the results are presented for different levels of input.
Źródło:
Archives of Electrical Engineering; 2016, 65, 3; 437-448
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of variable speed multiphase induction motor with pole phase modulation
Autorzy:
Liu, H.
Wang, J.
Zhang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/140991.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
induction motor (IM)
pole phase modulation (PPM)
efficiency
FEM
Opis:
The pole phase modulation (PPM) technique is an effective method to extend speed range and torque capabilities for an integrated starter and hybrid electric vehicles applications. In this paper, the five pole-phase combination types of a multiphase induction motor (IM) with 36 stator slots and 36 stator conductors are presented and compared quantitatively by using the time-stepping finite element method (TS-FEM). The 36 stator conductors of the proposed multiphase IM are fed by a 36 leg inverter and the current phase angle and amplitude of each stator conductor can be controlled independently. This paper focuses on the winding connection, the PPM technique and the performance comparative analysis of each pole-phase combination types of the proposed multiphase IM. The flux distribution, air-gap flux density, output torque, core losses and efficiency of five pole-phase combination types have been investigated.
Źródło:
Archives of Electrical Engineering; 2016, 65, 3; 425-436
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Torque ripple reduction in BLDC motor based ona PWM technique for open-end winding
Autorzy:
Baszyński, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/1841368.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
BLDC motor
open-end winding
PWM technique
unipolar modulation
Opis:
The article presents a modulation method for BLDC motors with unconnected windings. This method uses two full bridges (or three 12-switch H-bridges). The useof the described modulation enables reducing the motor current variable and increasing (fourfold in relation to the switching frequency) the motor current ripple frequency. Themost important benefit of using a 12-switch inverter is the twofold reduction of the dc-linkvoltage while maintaining the rated rpm (voltage reduction in comparison to a typical supplymethod). A voltage reduction causes a reduction in losses on semi-conductor elements. Thearticle also demonstrates that the proposed modulation technique significantly shortens thetime of current commutation between windings.
Źródło:
Archives of Electrical Engineering; 2021, 70, 1; 5-23
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Averaged models of pulse-modulated DC-DC power converters. Part II. Models based on the separation of variables
Autorzy:
Janke, W.
Powiązania:
https://bibliotekanauki.pl/articles/140855.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power converters
pulse width modulation (PWM)
BUCK
buck-boost
BOOST
averaged models
Opis:
The separation of variables approach to formulate the averaged models of DC-DC switch-mode power converters is presented in the paper. The proposed method is applied to basic converters such as BUCK, BOOST and BUCK-BOOST. The ideal converters or converters with parasitic resistances, working in CCM and in DCM mode are considered. The models are presented in the form of equation systems for large signal, steady-state and small-signal case. It is shown, that the models obtained by separation of variables approach differ in some situations from standard models based on switch averaging method.
Źródło:
Archives of Electrical Engineering; 2012, 61, 4; 633-654
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Averaged models of pulse-modulated DC-DC power converters. Part I. Discussion of standard methods
Autorzy:
Janke, W.
Powiązania:
https://bibliotekanauki.pl/articles/140859.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power converters
pulse width modulation (PWM)
BUCK
BOOST
buck-boost
averaged models
Opis:
The averaged models of switch-mode DC-DC power converters are discussed. Two methods of averaged model derivation are considered - the first, based on statespace averaging and the second, on the switch averaging approach. The simplest converters: BUCK, BOOST and BUCK-BOOST working in CCM (continuous conduction mode) or DCM are taken as examples in detailed considerations. Apart from the ideal converters, the more realistic case of converters with parasitic resistances is analyzed. The switch averaging approach is used more frequently than the other and is believed to be more convenient in practical applications. It is shown however, that in the deriving the averaged models based on the switch-averaging approach, some informalities have been made, which may be the source of errors in the case of converters with parasitic resistances, or working in DCM mode.
Źródło:
Archives of Electrical Engineering; 2012, 61, 4; 609-631
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DC-link voltage balancing in cascaded H-Bridge converters
Autorzy:
Lewicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/141491.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cascaded H-Bridge converter
DC-link voltage balancing
space-vector pulse width modulation
Opis:
In this paper a DC-link voltage balancing strategy for multilevel Cascaded H-Bridge (CHB) converter is proposed. Presented solution bases on optimal choice of active vector durations in Space-Vector Pulse Width Modulation (SV-PWM). It makes it possible to DC-link voltages control and to properly generate the output voltage vector in the case of DC-link voltage unbalance. Results of simulation and experimental researches on proposed control strategy are presented in the paper.
Źródło:
Archives of Electrical Engineering; 2014, 63, 3; 439-455
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficiency comparison between the LLCL and LCL-filters based single-phase grid-tied inverters
Autorzy:
Wu, W.
Huang, M.
Blaabjerg, F.
Powiązania:
https://bibliotekanauki.pl/articles/140537.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
LCL filter
LLCL-filter
efficiency power loss
modulation
single-phase grid-tied inverter
Opis:
An LLCL-filter is becoming more attractive than an LCL-filter as the interface between the grid-tied inverter and the grid due to possibility of reducing the copper and the magnetic materials. The efficiency of the LLCL-filter based single-phase grid-tied inverter also excites interests for many applications. The operation of the switches of the VSI is various with different modulation methods, which lead to different efficiencies for such a single-phase grid-tied inverter system, and therefore important research has been carried out on the effect of the choice of PWM schemes. Then power losses and efficiencies of the LLCL-filter and the LCL-filter based single-phase grid-tied inverters are analyzed and compared under the discontinuous unipolar, the dual-buck and the bipolar modulations. Results show that the efficiency of LLCL-filter based inverter system is higher than the LCL- filter based independent on the modulation method adopted. Experiments on a 2 kW prototype are in good agreement with results of the theoretical analysis.
Źródło:
Archives of Electrical Engineering; 2014, 63, 1; 63-79
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of control parameters on synchronization stability of virtual synchronous generator
Autorzy:
Zhang, Yanxia
Cheng, Yachao
Liu, Kaixiang
Han, Yue
Powiązania:
https://bibliotekanauki.pl/articles/2172794.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
control parameter
frequency modulation coefficient
phase plane method
synchronization stability
virtual synchronous generator
Opis:
Different from the synchronization mechanism of synchronous generators, the non-synchronous generators must be synchronized with the grid through a controller. Generally, the virtual synchronous generator (VSG) control strategy is adopted for this purpose. In view of the current situation, where the control loops are not comprehensively considered in the research of the synchronization stability of the VSG, this paper considers multiple control loops, such as active frequency loops, virtual governors, power filters and current constraint control, to establish the mathematical model of the VSG and infinite system. On this basis, the correlation formula between power angle difference and control parameters is deduced. Adopting the phase plane method, the influence of different control loops and their parameters on the transient synchronization stability is analyzed. Finally, a setting principle of the frequency modulation coefficient of virtual governors is proposed, which not only meets the response speed of control systems, but also has good control performance.
Źródło:
Archives of Electrical Engineering; 2022, 71, 4; 811--828
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Six-phase motor drive supplied by four voltage source inverters with synchronized space-vector PWM
Autorzy:
Oleschuk, V.
Grandi, G.
Powiązania:
https://bibliotekanauki.pl/articles/140418.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
podwójny układ trójfazowy
modulacja
synchronizacja napięcia
dual three-phase system
modulation strategy
voltage synchronization
Opis:
Novel method of space-vector-based pulsewidth modulation (PWM) has been disseminated for synchronous control of four inverters feeding six-phase drive based on asymmetrical induction motor which has two sets of windings spatially shifted by 30 electrical degrees. Basic schemes of synchronized PWM, applied for control of four separate voltage source inverters, allow both continuous phase voltages synchronization in the system and required power sharing between DC-sources. Simulations show a behavior of six-phase system with continuous and discontinuous versions of synchronized PWM.
Źródło:
Archives of Electrical Engineering; 2011, 60, 4; 445-458
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on torque ripple suppression of brushless DC motor based on PWM modulation
Autorzy:
Daode, Zhang
Wei, Lingkang
Hu, Xinyu
Zhang, Chupeng
Li, Xuesheng
Powiązania:
https://bibliotekanauki.pl/articles/141390.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DC brushless motor
electric propulsion
fuzzy PID control
torque ripple
PWM_ON_PWM modulation
Opis:
Brushless DC motors are often used as the power sources for modern ship electric propulsion systems. Due to the electromagnetic torque ripple of the motor, the traditional control method reduces the drive performance of the motor under load changes. Aiming at the problem of the torque ripple of the DC brushless motor during a noncommutation period, this paper analysis the reasons for the torque ripple caused by pulsewidth modulation (PWM), and proposes a PWM_ON_PWM method to suppress the torque ripple of the DC brushless motor. Based on the mathematical model of a DC brushless motor, this method adopts a double closed-loop control method based on fuzzy control to suppress the torque ripple of the DC brushless motor. The fuzzy control technology is integrated into the parameter tuning process of the proportional–integral–derivative (PID) controller to effectively improve the stability of the motor control system. Under the Matlab/Simulink platform, the response performance of different PID control methods and the torque characteristics of different PWM modulation methods are simulated and compared. The results show that the fuzzy adaptive PID control method has good dynamic response performance. It is verified that the PWM_ON_PWM modulation method can effectively suppress the torque ripple of the motor during non-commutation period, improve the stability of the double closed-loop control system and meet the driving performance of the motor under different load conditions.
Źródło:
Archives of Electrical Engineering; 2019, 68, 4; 843-858
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Field-oriented control of five-phase induction motor with open-end stator winding
Autorzy:
Listwan, J.
Pieńkowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/141002.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analysis
field-oriented control
five-phase induction motor
open-end winding
simulation studies
space-vector modulation
Opis:
The mathematical model of the five-phase squirrel-cage induction motor and the system of the dual five-phase voltage source inverter have been presented. The control methods and control systems of the field-oriented control of the five-phase induction motor with an open-end stator winding are described. The structures of the direct fieldoriented control system (DFOC) and the Indirect Field-oriented control system (IFOC) with PI controllers in outer and inner control loops are analyzed. A method of space vector modulation used to control the system of the dual five-phase voltage source inverter has been discussed. The results of simulation studies of the field-oriented control methods are presented. Comparative analysis of the simulation results was carried out.
Źródło:
Archives of Electrical Engineering; 2016, 65, 3; 395-410
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved virtual space vector modulation for neutral point voltage oscillation and common-mode voltage reduction in neutral point clamped three-level inverter
Autorzy:
Fang, Junlong
Wang, Guangya
Li, Ran
Liu, Siyuan
Wang, Shuyu
Powiązania:
https://bibliotekanauki.pl/articles/1841339.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
three-level inverter
vector conversion
virtual space vector modulation
falownik trójpoziomowy
konwersja wektorowa
modulacja wektora przestrzeni wirtualnej
Opis:
The neutral point clamped (NPC) three-level inverter is widely used in high-voltage and high-power applications. However, neutral point voltage oscillation (NPVO) and common-mode voltage (CMV) problems exist in the NPC three-level inverter. In this paper, an improved virtual space vector modulation (VSVM) is proposed based on the reconstruction of a virtual small vector and a virtual medium vector. Compared with the traditional VSVM, an improved VSVM can effectively reduce the CMV. On this basis, a vector conversion method is proposed to further reduce the NPVO in the whole range. Simulation results verify the effectiveness and superiority of the improved VSVM.
Źródło:
Archives of Electrical Engineering; 2021, 70, 1; 203-218
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Induction machine with pole-changing winding for turbomechanisms
Autorzy:
Bobojanov, Makhsud
Powiązania:
https://bibliotekanauki.pl/articles/24202741.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
basic scheme of winding
differential leakage factor
Görges polygone
magnetizing forces
pole-changing winding
pole amplitude modulation
winding factor
Opis:
This paper investigates the possibilities for developing a pole-changing winding with a pole ratio of 3:4 with improved electromagnetic properties. Such a winding can be used in two-speed induction motors for turbo mechanisms. The scheme of the new winding was obtained by using a discretely-specified spatial function method developed at the Tashkent State Technical University. A comparison of the parameters obtained for a similar winding received by the pole amplitude modulation method has been presented. Design of a new motor with a new winding is developed based on the standard induction motor. The paper presents results of laboratory tests, too.
Źródło:
Archives of Electrical Engineering; 2023, 72, 2; 415--426
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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