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Temporally and spatially resolved diagnostics of an electric arc
Holcner, Oldřich ; Šimek, David (referee) ; Kloc, Petr (advisor)
This batchelor thesis "Temporally and spatially resolved diagnostics of an electric arc" deals with the investigation of plasma temperature in an arc formed by evaporation of copper wire. It is an optical method based on determination of temperature from intensity of spectral lines. In this batchelor thesis we explain how spectral lines are formed and how to determine the temperature. In the practical part we process discharge and show the time evolution of temperature at the measured points.
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Enhancement of optical diagnostics of the switching arc
Samohejl, Matěj ; Kloc, Petr (referee) ; Valenta, Jiří (advisor)
This master´s thesis si focused on determinig methodology of optical diagnostics of the switching arc using the high-speed camera Photron SA-X2. The thesis contains basic rules for proper setup of the measurement system and the rules to adjust the camera exposure. The experiments were performed on the prototype of a parametric switching chambre, while the majority of source materials was derived from the requirements of another study which was aimed on the movement of the electode spots. The process of the first adjustment of the camera, a record edit options for the presentation purposes and the process of the 3D model design of the switching arc in SketchUp software was stated. Paper contains a comparsion of the spectral filter effect and neutral density filter effect on the final record as well. The part of the work outputs are the 3D model of the switching arc and the supporting record editing software. The paper results show a degree of the inaccuracies in a optical diagnostics made from only one direction caused by the lack of the information about third dimension.
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Technologies of the electrical apparatuses protyping
Svoboda, Filip ; Kloc, Petr (referee) ; Šimek, David (advisor)
The work focuses on the production of prototypes of electrical devices. The theoretical part contains a structured overview of the historical development of prototype production technologies and description of individual prototyping technologies. The main part of the work is the design of a prototype extinguishing chamber, printing of the chamber and verification of the ability to extinguish the electric arc.
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Investigation of correlation between arc voltage and arc movement
Szotkowski, Šimon ; Valenta, Jiří (referee) ; Kloc, Petr (advisor)
The electric arc burns in an ionized gas and is divided into AC and DC arc according to the power supply. The electric arc is conductive, so to turn off the electric circuit, the arc must be extinguished as soon as possible. Arc breakers are used to extinguish the arc. Arc breaker must be designed to withstand the increased pressures and temperatures caused by the arc. The purpose of the bachelor's thesis was to design and construct a arc breaker with the possibility of monitoring the movement of the arc with a high-speed camera. From the measured data, the dependence between the arc voltage and the movement of the arc root was determined by correlation analysis. Correlation analysis is used to calculate the possible existence of a dependence between two quantities with the correlation coefficient and testing.
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Simulation of charged particles motion in electrical and magnetic fields
Zavřel, Marek ; Kloc, Petr (referee) ; Aubrecht, Vladimír (advisor)
In the first part of this bachelor thesis has been explained a basic idea of plasma state. In the second part have been described charged particle motions in various configurations of electric and magnetic fields. These motions are: accelerating and deflection of charged particle by electric field, gyration in magnetic field and drift motion in crossed electric and magnetic fields. Principles of magnetic mirror and magnetic trap were described as well. In the third part have been described operating principles and manipulation with simulation program, which is the main outcome of this thesis. Simulation program draws trajectories of mentioned charged particle motions in homogenous electric and magnetic fields.
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Investigation on the Interaction between Construction Materials and Switching Arc in Low Voltage Switching Devices
Šimek, David ; Slavíček, Pavel (referee) ; Mindl,, Pavel (referee) ; Kloc, Petr (advisor)
The doctoral thesis is focused on the interaction of construction materials and the switching arc in low voltage switchgear. An issue of selected low-voltage electrical devices, electric arc in electrical devices, and its diagnostics using optical emission spectroscopy and high-speed video are discussed at the theoretical level. The main part of the work is an experimental examination of samples of selected high-performance industrial plastics. A series of tests of resistance to an electric arc were performed on these plastics. The electrical parameters of the switching process, the weight losses of the material of the quenching chambers when applying various power parameters were evaluated from the experiments. The empirical equations were determined for the calculation of the loss of individual materials in a specific configuration. Furthermore, the influence of the used material on the behavior of the electric arc in the extinguishing chamber made of these plastics was investigated. A high-speed video was recorded, the time evolution of the pressure inside the chamber, the electrical parameters of the arc, and the time-resolved evolution of the radiation spectra were measured using atomic emission spectroscopy in these measurements. The relative composition of the plasma was identified from the radiation spectra, and the time evolution of the relative contamination of the discharge area by the main contact material and the selected vapors of the used plastics was created. The last important parameter of the electric arc is its temperature, which was also calculated from the radiation spectra. A comparison of individual plastics and their applicability for applications in contact with electric arc was performed based on the obtained data.
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Switching arc diagnostics in DC contactor
Píška, Jakub ; Kloc, Petr (referee) ; Valenta, Jiří (advisor)
Cílem této diplomové práce bylo provést diagnostiku vysokonapěťového stejnosměrného stykače se zaměřením na zpětnou komutaci a lepení oblouku, navrhnout a ověřit úpravy, které odstraní tyto negativní jevy. Měření obloukového napětí, tlaku a pomocí rychlokamery byly použity při diagnostice těchto jevů. Změny na arcrunnerech a jhu magnetického obvodu byly využity při jejich odstraňování. Úpravy na arcrunneru zmenšily skokové nárusty délky oblouku a úpravy na jhu navýšily sílu na oblouk mezi rozevírajícími se kontakty. Navrhnuté změny na stykači snížily časovou ztrátu v důsledku zpětné komutace, a tak zkrátily čas přenosu oblouku.
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Global optimization of multiple variables functions
Vláčil, Stanislav ; Janda, Marcel (referee) ; Kloc, Petr (advisor)
Master’s thesis deals with numerical finding the global minimum. A theoretical part of project presents a problem of global optimization, her basic division and shows basic examples the specific problems of global optimization. Further, the reader is familiar with the basics of some numerical methods and with description of their strengths and weaknesses. A practical part shows concrete algorithm of global optimization, its use on data of specified function. Data refer to the issue of radiative heat transfer.
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Determination of the Temperature Field in a Real Circuit Breaker
Pěček, Dominik ; Aubrecht, Vladimír (referee) ; Kloc, Petr (advisor)
This master thesis deals with determination of temperature field in a real circuit breaker. This issue is solved by analysis of measured emission spectra at selected points of the circuit breaker. Spectral line ratios and Boltzmann plot are used for calculation of temperature. These methods are based on elemental analysis of plasma. The main result is finding significant changing of chemical composition of plasma beyond determination of temperature field.
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