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Wyświetlanie 1-15 z 19
Tytuł:
Steady-state modelling method for matrix-reactance frequency converter with boost topology
Autorzy:
Korotyeyev, I.Ye.
Zięba, B.
Powiązania:
https://bibliotekanauki.pl/articles/140872.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
przekształtnik AC/AC
matrycowo-reaktancyjny przemiennik częstotliwości
metoda Galerkina
równanie różniczkowe
AC/AC converters
matrix-reactance frequency converter
Galerkin's method
extension of differential equations
Opis:
This paper presents a method intended for calculation of steady-state processes in AC/AC three-phase converters that are described by nonstationary periodical differential equations. The method is based on the extension of nonstationary differential equations and the use of Galerkin's method. The results of calculations are presented in the form of a double Fourier series. As an example, a three-phase matrix-reactance frequency converter (MRFC) with boost topology is considered and the results of computation are compared with a numerical method.
Źródło:
Archives of Electrical Engineering; 2011, 60, 2; 137-148
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power flow controller based on bipolar direct PWM AC/AC converter operation with active load
Autorzy:
Kaniewski, Jacek Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/141487.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power flow controller
direct AC/AC converter
matrix chopper
power quality
Opis:
The uncontrolled power flow in the AC power system caused by renewable energy sources (restless sources, distributed energy sources), dynamic loads, etc., is one of many causes of voltage perturbation, along with others, such as switching effects, faults, and adverse weather conditions. This paper presents a three-phase voltage and power flow controller, based on direct PWM AC/AC converters. The proposed solution is intended to protect sensitive loads against voltage fluctuation and problems with power flow control in an AC power system. In comparison to other solutions, such as DVR, UPFC, the presented solution is based on bipolar matrix choppers and operates without a DC energy storage unit or DC link. The proposed solution is able to compensate 50% voltage sags, in the case of three-phase symmetrical voltage perturbation, and single phase voltage interruptions. Additionally, by means of a voltage phase control with a range of 60◦ in each phase, it is possible to control the power flow in an AC power system. The paper presents an operational description, a theoretical analysis based on the averaged state space method and four terminal descriptions, and the experimental test results from a 1 kVA laboratory model operating under active load.
Źródło:
Archives of Electrical Engineering; 2019, 68, 2; 341-356
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the matrix converter to power flow control
Autorzy:
Szcześniak, P.
Fedyczak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/141546.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
matrix converter
AC systems
power flow
Opis:
Advanced power electronic converters can provide the means to control power flow and ensure proper and secure operation of the future power grid. The small electrical energy sources dispersed in electrical power systems referred to as distributed generation are one of the most significant parts of future grids - Smart Grids. The threephase, direct matrix converter is an alternative solution to the conventional AC-DC-AC converter for interfacing two AC systems in distributed power generation with different voltage and/or frequency parameters. This paper presents a control analysis of a threephase matrix converter employed as a power interface of future electrical grids. The proposed system has been successfully tested for bidirectional power flow operation with different grid operating conditions, such as, frequency and voltage variation.
Źródło:
Archives of Electrical Engineering; 2014, 63, 3; 409-422
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A coefficient diagram method based AGC mechanism for an interconnected power system in coordination with UPFC and AC/DC link
Autorzy:
Sahani, A.K.
Shankaro, Ravi
Sariki, Murali
Mandal, Rajib Kumar
Powiązania:
https://bibliotekanauki.pl/articles/140700.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AGC
AC/DC link
CDM
GDB
GRC
UPFC
Opis:
Frequency regulation is in a first line of preference for an interconnected power system. Presence of nonlinearities in the generation systems further raises the complexity level of the problem. In this scenario, this article presents a robust Automatic Generation Control (AGC) mechanism to maintain the frequency and tie-line power of the power system to their nominal values. A Coefficient Diagram Method (CDM) based AGC mechanism including an AC/DC tie-line and Unified Power Flow Controller (UPFC) has been developed and the performance in handling the frequency regulation has been analyzed. The nonlinearities such as Governor Dead-Band (GDB) and Generation Rate Constraint (GRC) are included in the system to analyze the proposed AGC scheme in a more realistic approach. The AC/DC tie-line and UPFC which are included in the proposed AGC scheme provides an immense strength to handle the active power variation as-well-as frequency regulation. To develop a more effective AGC scheme, the parameters of an AC/DC tie-line and UPFC are optimized by successful implementation of the Fruit Fly Optimization Algorithm (FOA). The justification of the proposed AGC scheme has been carried out through a step by step verification such as justifying the CDM based controller, effectiveness of the proposed scheme and robustness of the system against parameters variation. The CDM based controller has been compared with the conventional controllers to elevate the effectiveness and the supremacy of the proposed AGC scheme has been examined by comparing with previously published work. The design and simulation of the work has been carried out by the MATLAB/Simulink® tool box.
Źródło:
Archives of Electrical Engineering; 2020, 69, 2; 287-302
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A modelling of AC voltage stabilizer based on a hybrid transformer with matrix converter
Autorzy:
Szcześniak, P.
Powiązania:
https://bibliotekanauki.pl/articles/140776.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AC voltage stabilizer
averaged model
hybrid transformer
matrix converter
Opis:
This article presents a study of an AC voltage stabilizer based on a three-phase hybrid transformer combined with a matrix converter. The proposed solution is used to control AC voltage amplitude and phase shift. By adjustment of these voltage parameters we can reduce the effects of overvoltage, voltage dips or lamp flicker. Such negative phenomena are very significant, particularly from the perspective of the final consumer and sensitive loads connected to the power network. Often the voltage in the power system can be adjusted using a mechanical or thyristor controlled regulator, which in a stepwise manner switches the taps of the electromagnetic transformer. The method for obtaining continuous control of the voltage magnitude and phase shift with the use of a conventional transformer with two output windings and a matrix converter is presented in this paper. The operating principles, mathematical model and properties of the proposed voltage stabilizers are discussed in this paper. The main part of the article will be devoted to the mathematical model which is based on an averaged equation. Computer simulation results are presented and compared with the results of a mathematical study.
Źródło:
Archives of Electrical Engineering; 2017, 66, 2; 371-382
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and reliability analysis of three phase z-source AC-AC converter
Autorzy:
Prasad, H.
Maity, T.
Powiązania:
https://bibliotekanauki.pl/articles/140661.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
real-time digital simulation (RTDS)
field programming gate array (FPGA)
hardware-in-the-loop (HIL)
z-source ac-ac converter
PID controller
Opis:
This paper presents the small signal modeling using the state space averaging technique and reliability analysis of a three-phase z-source ac-ac converter. By controlling the shoot-through duty ratio, it can operate in buck-boost mode and maintain desired output voltage during voltage sag and surge condition. It has faster dynamic response and higher efficiency as compared to the traditional voltage regulator. Small signal analysis derives different control transfer functions and this leads to design a suitable controller for a closed loop system during supply voltage variation. The closed loop system of the converter with a PID controller eliminates the transients in output voltage and provides steady state regulated output. The proposed model designed in the RT-LAB and executed in a field programming gate array (FPGA)-based real-time digital simulator at a fixedtime step of 10 μs and a constant switching frequency of 10 kHz. The simulator was developed using very high speed integrated circuit hardware description language (VHDL), making it versatile and moveable. Hardware-in-the-loop (HIL) simulation results are presented to justify the MATLAB simulation results during supply voltage variation of the three phase z-source ac-ac converter. The reliability analysis has been applied to the converter to find out the failure rate of its different components.
Źródło:
Archives of Electrical Engineering; 2017, 66, 4; 731-743
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The model of double-cage induction motor for the analysis of thermal fields in transient operations
Autorzy:
Mróz, J.
Powiązania:
https://bibliotekanauki.pl/articles/141544.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AC motors
heating
induction motors
squirrel cage motors
temperature rise
Opis:
Emergency motor switch-on happens occasionally while operating a doublesquirrel- cage motor at full supply voltage with the rotor blocked (e.g., in coal mills). After releasing the blockage, the by now heated motor is started up again. However, the mechanical stress caused by the increased temperature poses considerable hazards to the squirrel-cage winding. This paper presents a double-cage induction motor model for analysis of thermal fields in transient operation. The thermal field for the rotor of a doublesquirrel- cage motor of soldered or cast structure, operating in the conditions described, has been calculated in the present paper using a thermal network method. Measurement results have been presented for the double-squirrel-cage winding temperature for a soldered cage construction in the blocked rotor state.
Źródło:
Archives of Electrical Engineering; 2017, 66, 2; 397-408
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical approach calculating eigenfrequencies and modes of stator cores in AC machines
Autorzy:
Witczak, P.
Powiązania:
https://bibliotekanauki.pl/articles/140608.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dergania własne
równanie równiczkowe
natural vibration
AC machines
differential equations
Opis:
The paper describes analytical approach solving the problem of dynamic analysis of two-dimensional fields of vibrational displacements and rotations caused by magnetic forces acting on stator of AC machine. Final set of three differential equations converted into algebraic ones is given and it is confronted with numerical solutions obtained by finite element method.
Źródło:
Archives of Electrical Engineering; 2012, 61, 1; 47-56
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and simulation aspects of AC machines
Autorzy:
Popp, M.
Laza, P.
Mathis, W.
Powiązania:
https://bibliotekanauki.pl/articles/141659.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
State Space Modeling
AC Machines
ODE and DAE Solvers
MATLAB
Opis:
In the field of power and drive systems, electrical AC machines are mostly modeled using a set of explicit ordinary differential equations in a state space representation. It is shown, that by using other equation types for simulation, algebraic constraints arising from aggregating several machines to a more complex system can directly be considered. The effects of different model variants on numerical ODE/DAE solvers are investigated in the focus of this work in order perform efficient simulations of larger systems possessing electrical AC machines.
Źródło:
Archives of Electrical Engineering; 2016, 65, 2; 315-326
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the proximity and skin effects on copper loss in a stator core
Autorzy:
Młot, A.
Korkosz, M.
Grodzki, P.
Łukaniszyn, M.
Powiązania:
https://bibliotekanauki.pl/articles/141349.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
end winding
copper loss
iron loss
ac loss
skin effect
proximity effect
Opis:
Accurate prediction of power loss distribution within an electrical device is highly desirable as it allows thermal behavior to be evaluated at the early design stage. Three-dimensional (3-D) and two-dimensional (2-D) finite element analysis (FEA) is applied to calculate dc and ac copper losses in the armature winding at high-frequency sinusoidal currents. The main goal of this paper is showing the end-winding effect on copper losses. Copper losses at high frequency are dominated by the skin and proximity effects. A time-varying current has a tendency to concentrate near the surfaces of conductors, and if the frequency is very high, the current is restricted to a very thin layer near the conductor surface. This phenomenon of nonuniform distribution of time-varying currents in conductors is known as the skin effect. The term proximity effect refers to the influence of alternating current in one conductor on the current distribution in another, nearby conductor. To evaluate the ac copper loss within the analyzed machine a simplified approach is adopted using one segment of stator core. To demonstrate an enhanced copper loss due to ac operation, the dc and ac resistances are calculated. The resistances ratio ac to dc is strongly dependent on frequency, temperature, shape of slot and size of slot opening.
Źródło:
Archives of Electrical Engineering; 2014, 63, 2; 211-225
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design, development and verification of a new multilevel inverter for reduced power switches
Autorzy:
Mahato, Bidyut
Ranjan, Mrinal
Pal, Pradipta Kumar
Gupta, Santosh Kumar
Mahto, Kailash Mahto
Powiązania:
https://bibliotekanauki.pl/articles/2172807.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
7-level/13-level inverter
DC-AC converters
power-electronic switches
sinusoidal PWM
Opis:
Due to recent developments in the field of high-power and medium-voltage, the multilevel inverter has raised to such an extent owing to some of its amazing facts regarding harmonic spectrum, ease in control, reduced electromagnetic interference (EMI), filterless circuit, stress on power switches, common-mode voltage. This paper well describes a novel architecture of a single-phase multilevel inverter using a lesser number of overall components, especially the power switches. The proposed topology is generalized in the structure that can generate any number of voltage steps. A 7-level structure of the proposed topology is explained and is elaborately discussed. Simulation is carried out in MATLAB and corresponding experimental results verify the existence of the proposed multilevel inverter. The real-time experimental results were presented and are well verified by the simulation results for 7-level as well for 13-level across RL-Load. The nature of load current is also indicated as per the nature of load voltage. Nevertheless, the topology is further compared with some of the recent literature and found superior in each respect.
Źródło:
Archives of Electrical Engineering; 2022, 71, 4; 1051--1063
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Discharge channel displacement simulation in AC arc
Autorzy:
Daszkiewicz, T.
Tarczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/141374.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
łuk łączeniowy
łuk prądu przemiennego
switching arcs
arc motion velocity
computer AC arc simulation
Opis:
Results of 3-D of discharge channel displacement simulation, acquired by means of the Fluent program during one current half-period of AC arc, indicate that the obtained images of the phenomenon are qualitatively similar to those, recorded with a high-speed digital camera, while the computer simulation enables much a more comprehensive analysis of the acquired data. In addition to selected arc simulation frames and corresponding distributions of mass velocity vectors and current density vectors on a plane, the distributions of temperature, current density and mass velocity values are presented on the axis of the electrode arrangement model. The composite motion (continuous and jumping) of discharge channels was analyzed, taking into account mass displacement and matter state changes.
Źródło:
Archives of Electrical Engineering; 2010, 59, 1-2; 35-49
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic algorithm tuned IP controller for Load Frequency Control of interconnected power systems with HVDC links
Autorzy:
Selvakumaran, S.
Rajasekaran, V.
Karthigaivel, R.
Powiązania:
https://bibliotekanauki.pl/articles/140655.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
genetic algorithm
Load Frequency Control
IP controller
AC-DC tie-lines
interconnected thermal non-reheat power systems
Opis:
A new design of decentralized Load Frequency Controller for interconnected thermal non-reheat power systems with AC-DC parallel tie-lines based on Genetic Algorithm (GA) tuned Integral and Proportional (IP) controller is proposed in this paper. A HVDC link is connected in parallel with an existing AC tie-line to stabilize the frequency oscillations of the AC tie-line system. Any optimum controller selected for load frequency control of interconnected power systems should not only stabilize the power system but also reduce the system frequency and tie line power oscillations and settling time of the output responses. In practice Load Frequency Control (LFC) systems use simple Proportional Integral (PI) or Integral (I) controller. The controller parameters are usually tuned based on classical or trial-and-error approaches. But they are incapable of obtaining good dynamic performance for various load change scenarios in multi-area power system. For this reason, in this paper GA tuned IP controller is used. A two area interconnected thermal non-reheat power system is considered to demonstrate the validity of the proposed controller. The simulation results show that the proposed controller provides better dynamic responses with minimal frequency and tie-line power deviations, quick settling time and guarantees closed-loop stability margin.
Źródło:
Archives of Electrical Engineering; 2014, 63, 2; 161-175
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorithm for determining two-periodic steady-states in AC machines directly in time domain
Autorzy:
Sobczyk, T.J.
Powiązania:
https://bibliotekanauki.pl/articles/141171.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AC machines
steady state analysis
two-periodic solutions
analysis in time domain
discrete differential operator
iterative algorithms
Opis:
This paper describes an algorithm for finding steady states in AC machines for the cases of their two-periodic nature. The algorithm enables to specify the steady-state solution identified directly in time domain despite of the fact that two-periodic waveforms are not repeated in any finite time interval. The basis for such an algorithm is a discrete differential operator that specifies the temporary values of the derivative of the twoperiodic function in the selected set of points on the basis of the values of that function in the same set of points. It allows to develop algebraic equations defining the steady state solution reached in a chosen point set for the nonlinear differential equations describing the AC machines when electrical and mechanical equations should be solved together. That set of those values allows determining the steady state solution at any time instant up to infinity. The algorithm described in this paper is competitive with respect to the one known in literature an approach based on the harmonic balance method operated in frequency domain.
Źródło:
Archives of Electrical Engineering; 2016, 65, 3; 575-583
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The DC-side active filter with dual-buck full-bridge inverter for wind generators
Autorzy:
Chen, X-Q.
Zhao, S-W.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/141358.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multi-pulse ac-dc converter
auto-transformer
harmonic suppression
DC-side active filter
dual-buck full-bridge inverter
Opis:
This paper proposes a new dc-side active filter for wind generators that combines 12-pulse polygon auto-transformer rectifier with dc-side current injection method and dual-buck full-bridge inverter having not the “shoot-through” problem in conventional bridge-type inverters, and therefore this system with the character low harmonic distortion and high reliability. The proposed dc-side active filter is realized by using dual-buck full bridge converter, which directly injects compensation current at dc-side of two six-pulse diode bridges rectifiers. Compared with the conventional three-phase active power filter at ac-side, the system with the dc-side active filter draws nearly sinusoidal current by shaping the diode bridges output current to be triangular without using the instantaneous reactive power compensation technology, only using simple hysteretic current control, even though under load variation and unbalanced voltage disturbances, and while an acceptable linear approximation to the accurate waveform of injection current is recommended. The performance of the system was simulated using MATLAB/Simulink, and the possibility of the dc-side active filter eliminating current harmonics was confirmed in steady and transient states. The simulation results indicate, the system has a total harmonic distortion of current reduced closely to 1%, and a high power factor on the wind generator side.
Źródło:
Archives of Electrical Engineering; 2018, 67, 2; 263--277
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 19

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