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Stability Issues in Modern Power Systems
Koudelka, Jan ; Schürhuber, Robert (referee) ; Braciník,, Peter (referee) ; Toman, Petr (advisor)
Disertační práce se zabývá problematikou stability v moderních elektrizačních soustavách, které jsou typické nárůstem podílu obnovitelných zdrojů a integrací nových technologií. Práce je koncipována jako soubor vysvětlivek, komentářů a poznámek k recenzovaným článkům publikovaným autorem v konferenčních sbornících a časopisech. Vybrané publikace, prezentované v práci, se týkají tří tematických kategorií: dynamická (úhlová) stabilita elektrizační soustavy, frekvenční stabilita elektrizační soustavy a frekvenční odlehčování. Stěžejní prezentovaná témata jsou výpočty kritického času jako ukazatele dynamické stability a možnosti využití nových technologií jako jsou nabíjecí stanice pro elektromobily pro podporu soustavy v nouzovém stavu. Základní používanou metodou analýzy jsou dynamické simulace na zjednodušených modelech soustav.
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Grid Node Operation after Large Nuclear Unit Connection to the Grid
Prokop, Ondřej ; Varmuža, Jan (referee) ; Katovský, Karel (advisor)
The thesis deals with the analysis of the grid node operation after the connection the nuclear unit. The aim of the master´s thesis is to describe the influence of network´s faults to a nuclear unit. Thesis is dealing with three fundamental problems. An influence of short circuits and power imbalance on the synchronous generator of nuclear power plant and its operation of the island network. The thesis is focused especially on the nuclear unit. However, in the case of any failure in the network, it´s necessary to check other units and their protections in the test system because unit failure could cause the disintegration of the power network. For the purposes of the simulation a test system of the power network has been developed. The test system was optimized in the LUG software, which is used to calculate the power network. Transient simulations are performed in the MODES software. Single faults are configured with scenarios. Results are generated into output files. Analysis of influence network´s faults on the synchronous generator of nuclear power plants. The ability of the synchronous generator to restore the primary steady state or hold the new steady state during changes in operating parameters of the network is one of the important parts of the safe and reliable operation of the power network. During the short circuit the damped transient actions occur. With the extension of the short circuit duration, the amplitude of the transient action increases. The risk of the stability loss of a synchronous generator increases. Therefore, the critical clearing time of a short circuit is being defined, which is the time when there is not any loss of stability. Critical clearing time of research generator is sufficient to turn off the short circuit with the help of its protection (the worst case is 0,8 s). For example, by comparison with the hydroelectric power plant, the critical clearing time is much longer. Models of other power plants have been designed with high reliability so in the case of these faults, it doesn’t cause the disintegration of the power network. Creation of island grid is characterized by strong current surges. Units must be resistant to these surges. In the island grid fast changes of the electrical parameters often occurs. Therefore, units must respond to these changes as quickly as possible and in the broadest limits. For this purpose an island operation regulator is being used. In the case of surplus island grid in steam power plants a dump condenser can be used. This is an important ability of steam power plants because the units are able to react quickly to changes of electrical parameters in island grid. The main result of this thesis is the behavior of the nuclear power plant during various faults in the power network. Researched generator of the nuclear power plant is highly stable against faults in the power network based on the findings. The results allow to continue in this topic with real network and real unit of nuclear power plant.
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Use of the dynamic damper in hydrodynamics
Vrána, Jiří ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The master thesis deals with the possibility of using dynamic damper in hydrodynamics. Specifically, the assessment of the impact of dynamic damper on the dynamic stability of the fluid system when the system exhibited unstable behaviour prior to damper installation due to self-excited vibration. In the thesis is presented the algorithm for the calculation of pressure and flow pulsations based on the transfer matrix method, the transition matrices for different damper designs variants are derived. Using the algorithm, the effect of a damper placed in a stable and unstable fluid system is solved. The output of this work is software for solution of pressure and flow pulsations in the system with serially arranged hydrodynamic elements created in the MATLAB program.
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Design of a two-axis multi-spindle lathe carriage
Sedlář, Jiří ; Štěpánek, Vojtěch (referee) ; Hadraba, Petr (advisor)
This diploma thesis deals with the design of a two-axis multi-spindle lathe carriage. In the first part, there is made a research, and its aim is to find possible variants of design solutions. After the best rated variant was selected, the thesis further continues with the necessary technical calculations of the main design nodes such as a synchronous servomotor, ball screw, linear guide and bearing. The design itself was carried out with regard to calculations and the resulting model was examined in terms of dynamic stability. The subject of examination was to find the natural frequencies of the assembly and to determine the amplitudes of the oscillations which arise from the harmonic excitation force. Finally, Lobe diagrams for grooving and longitudinal turning operations were drawn.
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The effect of proprioceptive neuromuscular facilitation on the dynamic stability of the lower limbs among the female softball players
Borůvková, Kristýna ; Srbová, Radmila (advisor) ; Froňková, Eliška (referee)
The bachelor thesis focuses on dynamic stability in junior softball players and examines the possibilities of influencing it with interventions based on proprioceptive neuromuscular facilitation. The theoretical part of the work defines basic concepts, the practical part consists of a professional study. The female players of the selected sample were divided into experimental and control groups and their dynamic stability was measured by the Y-Balance test. The results were subsequently compared with the standardized deviation, which shows the limit of the risk of injury to the lower extremities. The measurements performed neither confirmed nor disproved whether it is possible to influence the dynamic stability of the lower limbs using proprioceptive neuromuscular facilitation.
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Aircraft simulation model and analysis tool
Búliková, Tereza ; Daněk, Vladimír (referee) ; Zikmund, Pavel (advisor)
Základem popisu pohybu letounu jsou pohybové rovnice. V letectví se vyskytují v několika formách, pro které se nabízí různá řešení. Práce uvádí nejběžnější používané typy rovnic, nastiňuje jejich odvození a uvádí příklady jejich řešení. Z rovnic pohybu lze také odvodit další charakteristiky, jako je například dynamická stabilita letounu, která je důležitá pro hodnocení bezpečnosti letu a jeho kvality. V práci jsou popsané kritéria hodnocení, přičemž praktická část práce spočívá ve vytvoření vyhodnocovacího softwaru v prostředí Matlab s možností hodnotit různé typy letadel. Splnění kritérií je jednou z podmínek úspěšné certifikace letounu. Dále byl na základě pohybových rovnic vytvořen letecký simulátor v prostředí Simulink, který využívá dvě zobrazovací prostředí - Unreal Engine a FlightGear a taktéž umožňuje simulovat let různých letadel na základě znalosti jejich stabilitních derivací.
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Design of a two-axis multi-spindle lathe carriage
Sedlář, Jiří ; Štěpánek, Vojtěch (referee) ; Hadraba, Petr (advisor)
This diploma thesis deals with the design of a two-axis multi-spindle lathe carriage. In the first part, there is made a research, and its aim is to find possible variants of design solutions. After the best rated variant was selected, the thesis further continues with the necessary technical calculations of the main design nodes such as a synchronous servomotor, ball screw, linear guide and bearing. The design itself was carried out with regard to calculations and the resulting model was examined in terms of dynamic stability. The subject of examination was to find the natural frequencies of the assembly and to determine the amplitudes of the oscillations which arise from the harmonic excitation force. Finally, Lobe diagrams for grooving and longitudinal turning operations were drawn.
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Use of the dynamic damper in hydrodynamics
Vrána, Jiří ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The master thesis deals with the possibility of using dynamic damper in hydrodynamics. Specifically, the assessment of the impact of dynamic damper on the dynamic stability of the fluid system when the system exhibited unstable behaviour prior to damper installation due to self-excited vibration. In the thesis is presented the algorithm for the calculation of pressure and flow pulsations based on the transfer matrix method, the transition matrices for different damper designs variants are derived. Using the algorithm, the effect of a damper placed in a stable and unstable fluid system is solved. The output of this work is software for solution of pressure and flow pulsations in the system with serially arranged hydrodynamic elements created in the MATLAB program.
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The issue a knee injury in the athletics (case study)
Petrušová, Kateřina ; Kaplan, Aleš (advisor) ; Komínková, Linda (referee)
Title: The overview of knee injury issue in athletics (case study) Student: Kateřina Petrušová Supervisor: PhDr. Aleš Kaplan, PhD. MBA Aims: The aim of this thesis was to analyze and go through different recondition program processes, set together for and apply recondition program on particular athlete, all this based on the study of literature directly related to knee injury in sports and athletics. Next to realize case study and thanks to different tests evaluate based on various indicators the efficiency of recondition program on selected indicators by athlete and student of UK FVS after injury and arthroscopy of a knee. Methodology: After initial literal research the recondition program was settled and was applied to the probant. During the recondition program were monitored parameters of body structure on Tanita BC 545, parameters of bottom limbs circumference and further the stability level, sensomotorics and symmetry using the MFT S3 Check device and finally the dynamic stability on Y Balance Test device. Results: I studied a lot of literature, which was directly related to knee injury. I read through 12 foreign and Czech titles. Especially abroad the knee injury problematics are often mentioned. Regarding the influence of athletic training on different parameters of the probant I indicated...
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Grid Node Operation after Large Nuclear Unit Connection to the Grid
Prokop, Ondřej ; Varmuža, Jan (referee) ; Katovský, Karel (advisor)
The thesis deals with the analysis of the grid node operation after the connection the nuclear unit. The aim of the master´s thesis is to describe the influence of network´s faults to a nuclear unit. Thesis is dealing with three fundamental problems. An influence of short circuits and power imbalance on the synchronous generator of nuclear power plant and its operation of the island network. The thesis is focused especially on the nuclear unit. However, in the case of any failure in the network, it´s necessary to check other units and their protections in the test system because unit failure could cause the disintegration of the power network. For the purposes of the simulation a test system of the power network has been developed. The test system was optimized in the LUG software, which is used to calculate the power network. Transient simulations are performed in the MODES software. Single faults are configured with scenarios. Results are generated into output files. Analysis of influence network´s faults on the synchronous generator of nuclear power plants. The ability of the synchronous generator to restore the primary steady state or hold the new steady state during changes in operating parameters of the network is one of the important parts of the safe and reliable operation of the power network. During the short circuit the damped transient actions occur. With the extension of the short circuit duration, the amplitude of the transient action increases. The risk of the stability loss of a synchronous generator increases. Therefore, the critical clearing time of a short circuit is being defined, which is the time when there is not any loss of stability. Critical clearing time of research generator is sufficient to turn off the short circuit with the help of its protection (the worst case is 0,8 s). For example, by comparison with the hydroelectric power plant, the critical clearing time is much longer. Models of other power plants have been designed with high reliability so in the case of these faults, it doesn’t cause the disintegration of the power network. Creation of island grid is characterized by strong current surges. Units must be resistant to these surges. In the island grid fast changes of the electrical parameters often occurs. Therefore, units must respond to these changes as quickly as possible and in the broadest limits. For this purpose an island operation regulator is being used. In the case of surplus island grid in steam power plants a dump condenser can be used. This is an important ability of steam power plants because the units are able to react quickly to changes of electrical parameters in island grid. The main result of this thesis is the behavior of the nuclear power plant during various faults in the power network. Researched generator of the nuclear power plant is highly stable against faults in the power network based on the findings. The results allow to continue in this topic with real network and real unit of nuclear power plant.
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