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Influence of terminal groups of oligobutadiene on dielectric spectra
Vilhelm, Ondřej ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The bachelor works discourses about atributes of KRASOL LB oligobutadiens by Sartomer industries and KRASOL LB’s final groups. The research proceed by dielectric sweep spectroscopy using electrode technology Agilent 16452A that is used for gauge of transtition capacity and dissipation factor, by which we are able to enumerate both relative permittivity [‘] and figure of loss [“]. Every gauge depends on frequency and temperature.
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Diagnosis of high voltage capacitors for cascade voltage multiplier
Baev, Dmitriy ; Zatloukal, Miroslav (referee) ; Krbal, Michal (advisor)
The main subject of the final thesis is to find a suitable method for measuring the partial discharge (PD) in the dielectric of high-voltage capacitor. In the theoretical part of thesis contains from the mechanisms of origin and the harmful effects of partial discharge at high voltage insulation of capacitor. It describes the global galvanic method of partial discharge measurement, the principle of cascade voltage multiplier, its main components (high-voltage capacitor and diode). Nowadays are presented the possibilities of measuring the quality of capacitors for voltage multipliers. In the experimental part of the diploma thesis is familiar with the diagnostics of high – voltage capacitors by means of laboratory measurements on the electronic bridge and with the help of partial discharge measurement system. It describes the design of a suitable electrode arrangement that eliminates the influence of the corona, which makes it impossible to measure partial discharges and the dissipation factor tg . The thesis analyzes the obtained data from measurements and determines the quality level or the degradation of the measured capacitors. The result of the project should be designed the methodology for finding poor quality capacitors in order to increase the reliability of the voltage multiplier.
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Electrical Properties Analysis Of Epoxy Resins With Various Fillers
Horák, Luděk
Presented thesis is focused on studying electroinsulating epoxy resin-based sealings. It describes a preparation of composite epoxy resin samples with different kinds of micro-ground siliceous sand as a filling. The samples given are measured on the temperature dependency of relative permitivity and dissipation factor.
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Measurement of dielectric properties of liquid fuels for automotive power units
Redr, Martin ; Čech, Ondřej (referee) ; Chladil, Ladislav (advisor)
This bachelor thesis dealt with measuring of dielectric properties of propellants. The aim of the thesis was to find out differences between dielectric quantities of propellants from various manufacturers and in different proportions of refined to so-called bio-components. The theoretical physical principles of dielectric substances – permittivity and dissipation factor were described. In the thesis the most famous electrical insulation fluids whose dielectric characteristics are similar as propellants were mentioned. Furthermore, the study about dielectric properties of propellants and chosen fuels on the Czech market were mentioned. In the experimental part of the thesis, selected fuel samples at varying frequency and temperature were measured. These results were then evaluated and compared.
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Dielectric properties of epoxy resins
Matoušová, Klára ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
This diploma thesis deals with the fundamental properties of epoxide mixtures, as determining of these fundamental properties of epoxide mixtures could in the case of favorable results lead to diminishing the amount of defects in epoxide-embedded instrument transformers. As the influence of effects in the manufacturing process of transformers causing poor quality is very extensit, the biggest emphasis is laid capitally on the influence of the epoxide casting mixture composition. The thesis describes the manufacture technology including used methodics and materials. The compositions of epoxide resins and the mechanisms of their curing. Also, the definitions of fundamental properties of dielectric materials and the description of diagnostic methods used to relative permitivity, dissipation factor and inner resistivity are included. suitable casts of acquired samples were set and dried out within the experimental part, followed by measurement of fundamental electrical properties in temperature and frequency relations. Hereafter a comparison of individual samples and the evaluation of their electrical properties will be carried out.
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Moisture Effect On Electrical Properties Of
The Composite Epoxy Resins
Horák, Luděk
The thesis presented is focused on studying electroinsulating epoxy resin-based sealings. The aim of the thesis is to compare several sets of samples of composite epoxy resins with different kinds of micro-ground siliceous sand as a filling. The temperature and frequency dependence of relative permittivity and dissipation factor are measured for given samples.
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