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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
461

Teplotní pole v tuhém palivu / Temperature field in solid fuel

Ptáček, Pavel January 2020 (has links)
The diploma thesis deals with a temperature field in a solid fuel during the combustion process. At the beginning of this thesis, research of available literature was conducted to obtain information about the composition of wood, properties affecting the combustion process, and the basics of heat transfer. Afterward, the temperature profiles of the samples were recorded during the measurement in the observation furnace. The temperature profiles of samples of six different sizes which were made of spruce and beech wood were subsequently evaluated and compared. Based on experimentally obtained data, a mathematical model was created in the OpenModellica software. Finally, the results of the mathematical model were compared with experimentally obtained data and appropriate conclusions were deduced.
462

Mechanický návrh simulátoru dopadu za snížené gravitace / Mechanical design of impact simulator under reduced gravity

Melichar, Marek January 2020 (has links)
The diploma thesis is focused on the development of the concept of a mechanical device that would meet the necessary requirements to achieve a successful simulation of reduced gravity or microgravity on the tested body at its impact. The choice of a suitable mechanism is based on a literary research of all available variants and highlight of their specifics. Target values are created for the selected method of testing, upon reaching which the concept will be considered successful. In order to verify the functionality of the concept, a mechanism is assembled on a smaller scale. The individual components of the mechanism are tested and carefully selected. All essential physical processes taking place in the system are mathematically described and combined into a MATLAB script. A separate application is created to calculate the behavior of the system based on the specified input parameters.
463

Parametry kabelových vedení / Power Cables Parameters

Váša, Lukáš January 2021 (has links)
In recent years, the development trend of power grids character shows increased demand for using cables of both current overhead and newly constructed lines. In order to preserve reliable operation and to predict the maintenance requirements, it is crucial to regard not only the parameters certified by manufacturers, but also externalities induced by real environment and incorporate these externalities into cable models in simulation software. The diploma thesis deals with determining of characteristic parameters of single core cables in real environment, which are affected by real grounding methods of metal shielding. The emphasis is put on analysis of current cable models in simulation software PSCAD and its evaluation using two-step experiment 1) measurement of shunt parameters in laboratory using electronic bridge model and 2) on field measurement of cable series parameters in real environment.
464

Matematický model synchronního motoru s permanentními magnety / Mathematical model of synchronous motor width permanent magnet

Fajkus, Petr January 2011 (has links)
The work is focused on the design of synchronous motor control with field weakening possibility. At present synchronous motors used in many applications. Often is used synchronous motor with permanent magnets. This type of motor may have different transverse and axial inductance. In most cases it is desirable to design the engine using a computer model. Therefore the synchronous motor described mathematically in order to create the model of motor. At work is also crated model of synchronous motor control. The control is designed for the highest possible speed range. Therefore, the motor control is consist of two parts. Speed is controlled by voltage in the first part. In the second part speed is controlled by field weakening. Everything is created and simulated in a computer program MATLAB-SIMULINK.
465

Fantomový přípravek pro perfusní zobrazování / Phantom model for perfusion imaging

Borovičková, Michaela January 2012 (has links)
This work focuses on issues relating to the perfusion analysis. The aim of this work is to perform experimental measurements of the phantom and then evaluate the perfusion curves. This curves are used to himation of perfusion hemodynamic parameters, which indicates important informatik about monitoring area. All processes associated with the designation and evaluation are performed in a program named Matlab. The output of work is a system that provides the reader into the problem of perfusion analysis and allows him to understand and know what is the meaning od analysis, what demands are placed on the evaluation and what is the result of this perfusion analysis.
466

Dynamický model a odbuzení bezkartáčového synchronního generátoru / Dynamic model and deexcitation of brushless synchronous generator

Chrobák, Petr January 2013 (has links)
This master thesis is focused on the synchronous generator mathematical model analysis. Based on the analysis are compiled mathematical models of main generator and exciter cooperating in brushless synchronous generator excitation system. Mathematical models of both machines are based on system of differential equations and their validity is verified in Matlab-Simulink. The master thesis is devided into three main parts. First part is focused on the derivation of differential equations to describe the behavior of electrical quantities of machines. In the second part are compiled and simulated mathematical models of both synchronous machines in Matlab-Simulink. The correctness of models are verified by approximate analytical calculations of selected steady and dynamic states. The last part is focused on design and simulation of concept for main generator rapid field winding deexcitation in brushless synchronous genereator excitation system.
467

Spolupráce mikro zdrojů v rámci malé smart grid / Cooperation of micro sources within small smart grid

Cabala, Ľuboš January 2013 (has links)
This thesis concerns with design of micro sources and their implementation in Micro grid system. In the first part the work is aimed at definition of smart - grid, where describes their advantages, disadvantages and necessary changes, which has to be made in current distribution network for implementation this system. Further on the thesis concerns with detailed description of Micro grid, configuration of this kind of network, the issues in implementation and possibilities to provide ancillary services. The work also describes marginally virtual power plants, presents definition, components and types of virtual power plants. The final chapter describes the creation of micro sources in System modeler and subsequent testing of consumption cover to operate in island mode.
468

Teorie vnitřního prostředí / The theory of internal environment

Blažková, Klára January 2013 (has links)
The aim of master's thesis is to find an optimal solution in terms of window shielding factors in shaping the internal environment in the interior. In therms of this work there was used a computer program Teruna to created mathematical model entered the room in the experimental section. The theoretical part inquires into the theory of the internal environment. The project inquires into the design and application of a mathematical model of two variants room office in the premises of the factory building.
469

Matematický model univerzální stanice v laboratoři VUT FSI OFI. / Mathematical model of circuit in laboratory VUT FSI OFI.

Klapal, Tomáš January 2008 (has links)
This diploma thesis deals with project and experimental verification of mathematical model of experimental circuit for measuring turbine in laboratory of Kaplan Department of Fluids Engineering FME BUT in Brno. Pressure and flow characteristics were modeled based on data measured on general-purpose experimental circuit. Possibilities of the circuit control, mainly by by-pass, were also taken into account. Characteristic curves should serve for preliminery design of the test circuit set up for the turbine model measurements.
470

Bezsensorové řízení BLDC motoru / Sensorless control of BLDC motor

Križan, Jakub January 2012 (has links)
This thesis is focused on problematics of control of brushless DC motor in the sensor and also in the sensorless mode. Also it interprets possibilities of BLDC motor control with one faulty sensor and derivation and simulation of mathematical model. First part mentions options of rotor position sensing as well as existing methods of sensorless BLDC motor control. Second part describes control algorithms of sensor and sensorless motor control realised on device dSPACE and also realisation of faulty sensor control algorithm. Third part deals with derivation of mathematical model, its realisation using Matlab Simulink software and identification of its parameters. Last part concludes results and compares control methods used on the real system.

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