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Finding The Fault Inception Time Using Wavelet Transform
Bukvisova, Zuzana
This paper deals with the transient detection method utilizing the wavelet transform, which proved to be more suitable for this purpose than the Fourier transform. The aim of this work is to analyze data, obtained from the power network model created in PSCAD software, and to determine the time of the fault inception. This calculated time is then compared with the actual fault inception time set in the model. The results show that the wavelet analysis can successfully detect all tested faults.
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Electrodynamic forces in low voltage switchgear assembly
Moravec, Štěpán ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
This bachelor thesis is focusd on issues of forces which are consecquences of an electrical current in an electric low-voltage switchboards. These forces are an effect of the magnetic fields arised from the electric current flowing in a circuit. We have to design electric switchboards which are in the process of use with emhasis on their safety, because the arisen forces are very high especially in a short-circuit. Each of new construction of an electric switchboard has to pass the type test in a testing laboratory for garanting their safety in operation. This thesis also examines the simulation on 3D model of an electric switch board by OEZ.
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Methods of Numerical Inversion of Laplace Transforms for Electrical Engineering and Their Applications
Al-Zubaidi R-Smith, Nawfal ; Machado,, José Tenreiro (referee) ; Biolek, Dalibor (referee) ; Brančík, Lubomír (advisor)
Numerické metody inverzní Laplaceovy transformace (NILT) se staly důležitou částí numerické sady nástrojů praktikujících a výzkumných pracovníků v mnoha vědeckých a inženýrských oborech, zejména v aplikované elektrotechnice. Techniky NILT zejména pomáhají při získávání výsledků simulací v časové oblasti v různých aplikacích. Příkladem jsou řešení obyčejných diferenciálních rovnic, které se objevují např. při analýze obvodů se soustředěnými parametry, nebo řešení parciálních diferenciálních rovnic objevujících se v systémech s rozprostřenými parametry, např. při zkoumání problematiky integrity signálů. Obecně platí, že většina dostupných 1D NILT metod je velmi specifická, tj. funguje dobře na několika typech funkcí a tudíž na omezeném počtu aplikací; Cílem této práce je podrobně se věnovat těmto numerickým metodám, vývoji univerzálních metod NILT a jejich rozšíření na multidimenzionální NILT, které mohou pokrývat širokou oblast aplikací a mohly by poskytnout praktický mechanism pro efektivnější způsob analýzy a simulace v časové oblasti. Myšlenky výzkumu jsou prezentovány v rámci diskusí nad širokou škálou případových studií a aplikací; Například metody NILT se používají při řešení přenosových vedení, včetně vícevodičových, a dokonce i při řešení slabě nelinárních obvodů při použití NILT více proměnných. Pomocí metody NILT mohou být s výhodou uvažovány parametry prvků závislé na kmitočtu a prvky necelistvých řádů v jejich příslušných modelech mohou být zahrnuty velmi přesným a jednoduchým způsobem.
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Proposal for loading tests of bridges - simulation and laboratory experiments
Bayer, Jan ; Urushadze, Shota ; Černý, Miloš
A new dynamic load testing of bridges is proposed and theoretically investigated. A transient analysis of passing vehicle over a bridge in ANSYS and an analytical program in MATLAB for the transient solution of piecewise linear mechanical structures were developed to assess the effects of the proposed dynamic load on a bridge model. According to the first laboratory experiments, it seems that the proposed travelling impulse load could surpass some of the shortcomings and limitations of the currently applied methods of bridge testing. The investigation is a part of a project aimed at drive-by identification of dynamic properties of bridges and further experimental and analytical research will follow.
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Seismic Analysis of The Pump 200-QHD
Čapičík, Martin ; Chlud, Michal (referee) ; Lošák, Petr (advisor)
The main goal of this thesis is dynamic analysis of shaft of booster pump QHD-200. In the beginning we offer basic equations generally used in dynamics and common/possible methods for their solution. Then we focus on specific problems connected with rotor dynamics and using simple Laval rotor we show their mathematical interpretation. Based on given load as accelerogram we create response spectrum in different ways (using different methods) and compare their CPU time demand. In the next part we make three finite element models of different physical level. We perform modal analysis and comparison of eigen frequencies, mode shapes. In following chapter transient analysis was performed on all models. As load we use accelerogram. We evaluate translations in particular positions of model. After that, we decide whether or not gap between impeller and stator case will be erased. Finally we make assessment of force acting upon bearings.
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Computational analysis of pressurized water reactor core behaviour using PARCS code
Novotný, Filip ; Ing. Jan Frýbort, Ph.D., KJR FJFI ČVUT v Praze (referee) ; Katovský, Karel (advisor)
The Master Thesis performs search concerning advanced small and medium power light-water reactors’ designs, including different possibilities to gain a license for their development and operation. The work covers the principal theory about the area of neutronics calculations, principal equations and simplifications. There are several different methods for solution of neutronics calculations. The thesis gives an overview of two principal groups of codes – deterministic methods and Monte Carlo method. The survey shows computational codes examples based on mentioned methods. The computational code PARCS is chosen for further study, which contained description of the input and output file, process of the model creation and conditions for neutronics calculation the of selected reactor design. Based on these facts, the transient calculation has been prepared within the thesis. Thee analyses are described – reactor emergency shutdown, reactor shutdown with stuck group of control and emergency shutdown rods and reactor shutdown with faulty reaction of emergency shutdown rods.
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Didactic program for transient analysis
Kříž, Petr ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to create didactic program for transient analysis in the environment of C++ Builder. For the disposal we have pre-defined bank of inertial circuits, that we can change at will and enlarge with the help of implemented editor of circuits. If we want to make an analysis, we will choose random circuit from offered palette and put in our values of components RLC. Subsequently, we specify if we want to know ´image´ of function F(p) of impulse or transient characteristic, finally we push the button ´Execute´. The program will display demanded ´image´ of function F(p) and simultaneously figure out ´original´ of function f(t) with the help of implemented Heavisides figures. This function is acceptable for display in time, which make this program enable. It is easy to find out by the change of time axis, when comes to stabilization of transient analysis and with the help of moving cross exactly establish in which time it has happened and what is the value of transmission, voltage or current in the curciut at the moment. Achievement results shall be print out.
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Synchronous generator reactance prediction using FE analysis
Chmelíček, Petr ; Lapčík, Josef (referee) ; Ondrůšek, Čestmír (advisor)
Parametry nahradniho obvodu synchronniho stroje znance ovlivnuji jeho chovani jak pri statickem provozu, tak predevsim pri nahlych dynamickych jevech a poruchovych stavech. Prace je zamerena na zhodnoceni dostupnych metod pro vypocet techto parametru pomoci Metody konecnych prvku. Prvni cast je venovana teoretickemu popisu zakladnich principu Metody Konecnych Prvku a jejich aplikaci na reseni problemu elektromagnetickeho pole v elektrickych strojich. Zaroven take shrnuje zakladni usporadani nahradniho obvodu synchroniho stroje, principi jeho konstrukce a zakladni funkci. Druha cast je venovana praktickemu vypoctu reaktanci nahradniho obvodu synchronniho stroje. S pomoci MKP jsou vypocteny synchronni reactance s uvazovanim vzajmeneho magnetickeho pusobeni proudu v d a q ose. Pro vypocet transientnich a subtransientnich reaktanci jsou navrzeny ctyri odlisne metody a jsou zhodnoceny z hlediska pozadovane presnosti vypoctu a narocnosti na vypocetni cas. Zaverecna cast popisuje zakladni merici metody pro urceni parametru nahrandniho obvodu na skutecnem stroji. Kapitola take obsahuje srovnani simulace trifazoveho zkratu synchronniho stroje s realnou zkouskou provedenou laboratorne. Zaver obsahuje srovnani jednotlivych metod a navrh optimalniho postupu pro vypocet zkoumanych parametru.
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