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Wyszukujesz frazę "transient model" wg kryterium: Temat


Tytuł:
An improved model of a three phase induction motor incorporating the parameter variations
Autorzy:
Dey, A.
Tripathi, A.
Singh, B.
Dwivedi, B.
Chandra, D.
Powiązania:
https://bibliotekanauki.pl/articles/262793.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
mathematical modeling
transient model
parameter variations
Opis:
A great deal of work is being done on the betterment of control through simulation of the electric drives used for various high-power purposes. The authenticity of the simulated results is based on the accurate modeling of the various parts of the electric drive system. Three–phase Induction motors form an extremely important part of the modern day electric drive system and their usage is continuously on a rise owing to their inherent properties of ruggedness, minimum maintenance requirements and continually increasing efficiencies. Usually the three-phase Induction motor model used in various research works does not incorporate stator and rotor core losses, stator and rotor stray load losses and magnetizing saturation and rotor conductor skin effects. The present paper aims at developing a threephase Induction motor model taking the above losses and effects into account. The dynamic linking of the model to a thermal model considering the temperature dependent resistive elements is an added feature. The motor model described in this paper is the extension of the conventional 2-phase lumped-parameter induction motor model. The biggest advantage is that the model is user-programmable in MA TLAB environment and can be used for system level transient studies. The simulation results of the developed model, with various parameter variations taken into account and subjected to sudden changes in load, show better torque and speed performances of the motor both in steady state and dynamic conditions.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 1; 73-78
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal dynamics of a building
Autorzy:
Matysko, R.
Dyczkowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/175263.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
transient model
thermal loss
thermal inertia
building
Opis:
The work presents the thermal dynamics of the building. The mathematical model covers the issues of heat exchange and temperature control in the room due to changing environmental conditions. The presented work describes the operation of the control system due to thermal losses and thermal inertia of the building. Mathematical model introduces a new method of thermal loss analysis in the conditions of variable thermal dynamics of the building.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2018, 141; 31-40
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electromechanical transient modeling of energy storage based on virtual synchronous machine technology
Autorzy:
Cui, Juntao
Li, Zhao
He, Ping
Gong, Zhijie
Dong, Jie
Powiązania:
https://bibliotekanauki.pl/articles/2135738.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
battery energy storage system
electromechanical transient model
virtual synchronous machine
Opis:
This paper proposes an electromechanical transient method to build a battery energy storage system-based virtual synchronous generator model, suitable for a large-scale grid. This model consists of virtual synchronous generator control, system limitation and the model interface. The equations of a second-order synchronous machine, the characteristics of charging/discharging power, state of charge, operating efficiency, dead band and inverter limits are also considered. By equipping the energy storage converter into an approximate synchronous voltage source with an excitation system and speed regulation system, the necessary inertia and damping characteristics are provided for the renewable energy power system with low inertia and weak damping. Based on the node current injection method by the power system analysis software package (PSASP), the control model is built to study the influence of different energy storage systems. A study on the impact of renewable energy unit fluctuation on frequency and the active power of the IEEE 4-machine 2-area system is selected for simulation verification. Through reasonable control and flexible allocation of energy storage plants, a stable and friendly frequency environment can be created for power systems with high-penetration renewable energy.
Źródło:
Archives of Electrical Engineering; 2022, 71, 3; 581--599
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modifying the Transient Overvoltages in Mixed Power Networks by Inserting Cable Sections
Autorzy:
Saied, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/262837.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
cable
overvoltage
transformer
veutral treatment
transient model
lightning
mixed power networks
Opis:
The paper deals with the analysis of the electromagnetic transients in mixed power net-works. Special emphasis is made on assessing the effectiveness of using cable sections in reducing the transients in the power network components such as transformer substations. A distributed parameter modeling of the overhead lines, underground cables and transformer windings is applied in the Laplace domain. The simulation can handle the different time waveforms of the sources initiating the transients, the lengths of the cable sections as well as the transformers’ neutral treatment. The direct analytical s-domain solution is numerically inverted in order to get the corresponding time domain results. The affecting parameters such as the line and cable surge impedances, the length of the cable section (or its time delay) and the transformer data, are investigated. A case involving multiple-pulse lightning surges is also addressed. The results of four case studies of known solutions are presented in order to validate the developed mathematical model and computer program.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2015, 18, 1; 7-14
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transient model of heat pump cycle
Autorzy:
Matysko, R.
Powiązania:
https://bibliotekanauki.pl/articles/95327.pdf
Data publikacji:
2018
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
heat pump
transient model
refrigeration cycle
MIMO controller
pompa ciepła
model przejściowy
obieg chłodniczy
sterowanie MIMO
Opis:
This paper introduce a transient model of the propane heat pump cycle. The heat pump cycle model includes: a compressor model, a condenser model in lumped parameters, an evaporator model in lumped parameters, an expansion valve model, a heat source model (cooling chamber), a PID control system for heat recovery from superheated refrigerant vapour. The model allows estimate inertia of the heat pump cycle with the system of the heat recovery from superheated propane vapor. The presented theoretical model can determine unsteady and steady state conditions of the different subsystems in the heat pump cycle (condenser, evaporator, compressor). The article presents the results of calculations and determines the time of reaching steady states of the key systems of the heat pump system. The article also presents (in a graphical form) the behavior of the system where the setting was changed after reaching the steady state after 2000s from 50kW to 40kW at the thermal load of the additional heat recovery exchanger.
Źródło:
Journal of Mechanical and Energy Engineering; 2018, 2, 2; 139-146
2544-0780
2544-1671
Pojawia się w:
Journal of Mechanical and Energy Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transient approach for iron loss separation of non-grain-oriented electrical steels considering the impact of cut edge effect
Autorzy:
Mülder, Christoph
Elfgen, Silas
Hameyer, Kay
Powiązania:
https://bibliotekanauki.pl/articles/140851.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cut edge effect
hysteresis losses
iron losses
transient loss model
Opis:
The purpose of this paper is to focus on the loss separation of non-grain-oriented electrical steels used for speed-variable rotating electrical machines. The impact of laser-cutting, used in prototype manufacturing and of flux density harmonics, occurring locally in the lamination, on the loss distribution is studied in detail. Iron losses occurring under operation can physically be separated in different loss components. In this paper, a frequency-based loss model with parameters identified for single-sheet tester specimens, cut in strips of different widths, is therefore used. Moreover, a time-domain approach considers loss distributions occurring from higher harmonics. Hysteresis losses having high sensitivity to cut edge effects are calculated by the well-known Jiles-Atherton model adapting the frequency-based loss parameters. The model is validated by free-curve measurements at a single-sheet tester. It has been shown that the studied elliptical hysteresis model becomes inaccurate particularly for specimens with small strip widths with similar dimensions as teeth of electrical machine laminations. The incorrect mapping of losses occurring from minor hysteresis loops due to higher harmonics is concluded. The results showconsequently that both, the impact of a cut edge effect and local distributions of flux density harmonics need to be considered in terms of accurate iron loss prediction of electrical machine design.
Źródło:
Archives of Electrical Engineering; 2019, 68, 2; 237-244
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes of the thermodynamic parameters in failure conditions of the micro-CHP cycle
Autorzy:
Matysko, R.
Mikielewicz, J.
Ihnatowicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/239967.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro-CHP system
transient model
failure states
multifuel boiler system
heating system
układ mikro CHP
model przejściowy
stan awaryjny
kocioł
system ogrzewania
Opis:
The paper presents the calculations for the failure conditions of the ORC (organic Rankine cycle) cycle in the electrical power system. It analyses the possible reasons of breakdown, such as the electrical power loss or the automatic safety valve failure. The micro-CHP (combined heat and power) system should have maintenance-free configuration, which means that the user does not have to be acquainted with all the details of the ORC system operation. However, the system should always be equipped with the safety control systems allowing for the immediate turn off of the ORC cycle in case of any failure. In case of emergency, the control system should take over the safety tasks and protect the micro-CHP system from damaging. Although, the control systems are able to respond quickly to the CHP system equipped with the inertial systems, the negative effects of failure are unavoidable and always remain for some time. Moreover, the paper presents the results of calculations determining the inertia for the micro-CHP system of the circulating ORC pump, heat removal pump (cooling condenser) and the heat supply pump in failure conditions.
Źródło:
Archives of Thermodynamics; 2014, 35, 1; 43-59
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cause investigation of metro corrugation in vehicle braking section of track
Autorzy:
Wang, Zhiqiang
Lei, Zhenyu
Powiązania:
https://bibliotekanauki.pl/articles/2055056.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
metro
braking section
rail corrugation
transient rolling contact model
friction self-excited vibration
Opis:
In order to study the cause of rail corrugation in the tangential braking section near the metro entrance, a transient rolling contact model of three-dimensional solid wheelset-track was established by using the finite element software ABAQUS, and the corrugation phenomenon was analyzed in the time-domain and frequency-domain based on the field measurement. The results show that the unstable friction self-excited vibration of the wheelset-track system is the fundamental cause of rail corrugation in the measured section, and it is precisely because of the “saturated-unsaturated” periodic characteristic of the wheel-rail creep force that ultimately promotes the formation of rail corrugation.
Źródło:
Journal of Theoretical and Applied Mechanics; 2021, 59, 4; 637--647
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative calculation of heat exchange with the ground in residential building including periodes of heat waves
Weryfikacja niestacjonarnego modelu do obliczeń temperatury w jednorodzinnych budynkach mieszkalnych podczas fal upałów
Autorzy:
Staszczuk, A.
Kuczyński, T.
Wojciech, M.
Ziembicki, P.
Powiązania:
https://bibliotekanauki.pl/articles/395787.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
transient calculation model
ground heat storage
heat waves
time series
niestacjonarna wymiana
model do obliczeń
wymiana ciepła z gruntem
fale upałów
szeregi czasowe
Opis:
The paper provides verification of 3D transient ground-coupled model to calculation of heat exchange between ground and typical one-storey, passive residential building. The model was performed with computer software WUFI®plus and carried out to estimate the indoor air temperatures during extending hot weather periods. For verifying the results of calculations performed by the WUFI®plus software, the most recent version of EnergyPlus software version was used. Comparison analysis of calculation results obtained with the two above mentioned calculation method was made for two scenarios of slab on ground constructions: without thermal insulation and with thermal insulation under the whole slab area. Comprehensive statistical analysis was done including time series analysis and descriptive statistics parameters.
W artykule przedstawiono weryfikację modelu 3D, będącego elementem programu komputerowego WUFI®plus do obliczeń niestacjonarnej wymiany ciepła budynku z termicznym sprzężeniem z gruntem. Za pomocą tego modelu oszacowano kształtowanie się temperatury wewnątrz jednorodzinnego, pasywnego budynku mieszkalnego podczas fali upałów. W celu weryfikacji przyjętego modelu zastosowano inny, bardziej rozpowszechniony model używany w programie komputerowym EnergyPlus. W artykule przedstawiono analizę porównawczą wyników obliczeń otrzymanych z zastosowaniem obu programów komputerowych dla dwóch wariantów konstrukcji podłogi na gruncie: bez izolacji termicznej oraz z izolacją termiczną pod płytą na całej jej powierzchni. Ponadto sporządzono analizą statystyczną otrzymanych wyników, uwzględniającą analizę szeregów czasowych oraz parametrów statystyki opisowej.
Źródło:
Civil and Environmental Engineering Reports; 2016, No. 21(2); 109-119
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Static And Dynamic Tariffing Electric Power Autonomous Microgrid
Autorzy:
Zhuikov, V.
Yamnenko, J.
Tereschenko, T.
Klepach, L.
Boiko, I.
Powiązania:
https://bibliotekanauki.pl/articles/410523.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
static model
dynamic model
price
isolated system
Fisher equation
transient processes
Opis:
The paper presents a static model of the price calculation for the various alternative electricity sources, and includes technical and economic performance of different energy sources for the guaranteed power. The table with calculated technical and economic indicators for various alternative energy sources is provided. The presented dynamic model which unites energy indicators of power generating systems and economic indicators of the closed macroeconomic system because price regulation on the power market of Ukraine happens in a statics. That’s why not allowed to perform an assessment of dynamic change of the tariff price of the electric power in the local isolated systems. When abrupt change isolated power generating capacity of the system is changing the tariff price of electricity cannot be taken into account when using static models. An example of the isolated system consisting of the diesel generator and the consumer is reviewed. The model allows to research influence of transition processes of the generator on change of cost indicators of an economic system, and also to estimate the adequate tariff price both for the producer, and for consumers of the electric power. This model is modelled in Matlab.
Źródło:
Present Problems of Power System Control; 2016, 7; 29-41
2084-2201
Pojawia się w:
Present Problems of Power System Control
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the accuracy of detailed model inductance matrix estimation for air core winding
Autorzy:
Ahour, J. N.
Seyedtabaii, S.
Gharehpetian, G. B.
Powiązania:
https://bibliotekanauki.pl/articles/140614.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
detailed transformer model
transient
inductance matrix and homogeneous
structure
Opis:
Researchers have used various methods to determine the parameters of transformer- equivalent circuits in transient studies. But most of these previous algorithms had difficulty finding the equivalent circuit parameters in a bigger model. This paper presents a new method to extract the inductance matrix of a detailed model for an air core winding for transient studies using frequency-response measurement data. This matrix can be determined with acceptable accuracy by using the proposed method. The biggest advantage of the proposed method is a reduction in the search space, and thus, speedier problemsolving. Simulations showed that the use of the proposed method leads to better behavioural quality of a transformer winding. The simulation results of the previous and proposed methods were compared with the help of a 20/0.4 kV, 1600 kVA transformer. This comparison showed the accuracy and superiority of the proposed method.
Źródło:
Archives of Electrical Engineering; 2017, 66, 4; 787-799
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of the reciprocating engine using iterative procedures of the transient torque calculation
Autorzy:
Kropiwnicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/246954.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
reciprocating engines
transient conditions
torque calculation
iterative procedures
black box model
Opis:
Process of development of vehicles is nowadays preceded by extensive modelling tests, which allow evaluating influence of applicable design solutions on future utilitarian parameters of the vehicle. Here, estimation of vehicle's dynamics by measuring of acceleration time from 0 to 100 km/h can be an example. Similar, maximal speed, pollutants emission or fuel consumption under speciflc conditions of vehicle's operation can be the example. Modelling research allow to shorten time of introduction of new vehicle for production significantly. Most eager group of model used in simulation tests of vehicles, according to short time of calculation, is black box models. They do not take into consideration they cyclic type of operation, however, it is possible to identify fast and simple their coefficients. This work involves description of reciprocating engine tests, which have been done under transient and steady-state conditions. Transient conditions were forced by rapid change of engine control signal. During the tests differences of torque generated by engine under transient and steady-state conditions have been registered for the same control signal. Basing on the received results a new algorithm of transient torque calculation has been proposed. In the presented model value of the transient torque has been combined with the engine control signal and others engine parameters, which deser ibe transient history of the engine. Hence, iterative procedures of the transient torque calculation with declared time step have been implemented.
Źródło:
Journal of KONES; 2010, 17, 2; 257-264
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of resisdence time measurements on heat exchangers for the determination of dispersive Peclet numbers
Autorzy:
Roetzel, W.
Na Ranong, C.
Powiązania:
https://bibliotekanauki.pl/articles/240480.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat exchanger
dispersion model
transient tracer experiment
evaluation method
wymiennik ciepła
model dyspersji
metoda oceny
Opis:
The recently developed special unity Mach number dispersion model prescribes the corrections to heat transfer coefficients which are simple functions of the dispersive Peclet numbers. They can be determined through the residence time measurements. An evaluation method is described in which the measured input and response concentration profiles are numerically Laplace transformed and evaluated in the frequency domain. A characteristic mean Peclet number is defined. The method is also applied to the parabolic dispersion model and the cascade model. A calculated example of a tube bundle with maldistribution and backflow demonstrates the suitability of the evaluation method.
Źródło:
Archives of Thermodynamics; 2014, 35, 2; 103-115
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical modelling of heat transfer in liquid flat-plate solar collector tubes
Autorzy:
Zima, W.
Dziewa, P.
Powiązania:
https://bibliotekanauki.pl/articles/240431.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kolektor słoneczny
model matematyczny
rozwiązanie dokładne
stan przejściowy
exact solution
mathematical model
solar collector
transient state
Opis:
The paper presents a one-dimensional mathematical model for simulating the transient processes which occur in the liquid flat-plate solar collector tubes. The proposed method considers the model of collector tube as one with distributed parameters. In the suggested method one tube of the collector is taken into consideration. In this model the boundary conditions can be time-dependent. The proposed model is based on solving the equation describing the energy conservation on the fluid side. The temperature of the collector tube wall is determined from the equation of transient heat conduction. The derived differential equations are solved using the implicit finite difference method of iterative character. All thermo-physical properties of the operating fluid and the material of the tube wall can be computed in real time. The time-spatial heat transfer coefficient at the working fluid side can be also computed on-line. The proposed model is suitable for collectors working in a parallel or serpentine tube arrangement. As an illustration of accuracy and effectiveness of the suggested method the computational verification was carried out. It consists in comparing the results found using the presented method with results of available analytic solutions for transient operating conditions. Two numerical analyses were performed: for the tube with temperature step function of the fluid at the inlet and for the tube with heat flux step function on the outer surface. In both cases the conformity of results was very good. It should be noted, that in real conditions such rapid changes of the fluid temperature and the heat flux of solar radiation, as it was assumed in the presented computational verification, do not occur. The paper presents the first part of the study, which aim is to develop a mathematical model for simulating the transient processes which occur in liquid flat-plate solar collectors. The experimental verification of the method is a second part of the study is not presented in this paper. In order to perform this verification, the mathematical model would be completed with additional energy conservation equations. The experimental verification will be carry out in the close future.
Źródło:
Archives of Thermodynamics; 2010, 31, 2; 45-62
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical approach to the standard model of water hammer with fluid-structure interaction
Autorzy:
Henclik, S.
Powiązania:
https://bibliotekanauki.pl/articles/281051.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
water hammer
transient pipe flow
fluid-structure interaction
standard model
method of characteristics
Opis:
In the classic water hammer (WH) theory, 1D liquid flow in a quasi-rigid pipe is assumed. When the pipe is flexible or is fixed to the foundation with elastic supports, the dynamic fluid structure interaction (FSI) should be taken into account for more accurate modelling of the system behaviour. The standard model of WH-FSI for a straight pipe reach is governed by fourteen hyperbolic partial differential equations of the first order, two for 1D liquid flow and twelve for 3D motion of the pipe. This model is presented in the paper and an algorithm for its numerical solution based of the method of characteristics is proposed. Basic boundary conditions (BC) are shortly discussed. The important condition at the junction of two subpipes fixed to the foundation with a viscoelastic support is presented in details and a general method of its solution is proposed.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 543-555
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł

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