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Short Circuit Currents in DC Systems
Kolařík, Robin ; Geschwinder, Lukáš (referee) ; Paar, Martin (advisor)
The bachelor thesis deals with the analysis of short-circuit currents in DC systems. The thesis introduces the possibility of application of low voltage DC distribution in commercial and industrial buildings. The second part is focused to high voltage direct current transmission. The practical part deals with the calculation of short-circuit currents of individual elements and subsequently with short-circuit conditions in the DC network. At the end of the work are evaluated advantages and disadvantages between AC and DC voltage and suitability of use in given areas.
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Capacitance measurement of high-voltage PN junctions
Derishev, Anton ; Kosina, Petr (referee) ; Boušek, Jaroslav (advisor)
The work deals with the capacitance measurement of high-voltage PN junctions. The work is divided into theoretical and practical parts. The theoretical part presents insight into the fundamental properties of PN junctions and methods for measuring of the capacitance of PN junctions, primarily by C-V measurement. In the practical part, several kinds of measuring circuits are introduced and a suitable method of measurement is found. The calculations of basic parameters - the width of the base and resistivity are presented and discussed. The results were compared with the values obtained by calculation from the technological parameters of the junction.
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Operation of embedded cable lines into HV distribution grid
Černý, Tomáš ; Wasserbauer, Vojtěch (referee) ; Ptáček, Michal (advisor)
The thesis focuses on a section of cable line inserted into overhead high voltage power line. The essence is a description of the benefits, risks and impacts of the operation of such sections in terms of protection, transition processes. etc. The thesis also includes economical comparison of an acquisition and operating costs of both overhead and cable line. The topic of this thesis was given by ČEZ Distribuce a.s.
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Hihg voltage measurement at atmospheric potentials
VÁŇA, Jan
The diploma thesis deals with the experimental construction of a non-contact high-voltage voltmeter for measuring potentials on the basis of generally known and available data. The aim of this work is clear description of the production procedure, functional measuring device, comparison of the influence of material and shape of electrodes on the measurement itself. Another goal of the work is also a general direction to reusing unnecessary or non-functional parts and materials, usually intended for disposal, in various structures.
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Design of a 22 kV network in the Lipno area after the integration of the new 110/22 kV transformer station
Žižlavský, Jakub ; Koudelka, Jan (referee) ; Ptáček, Michal (advisor)
This diploma thesis deals with the design of a new 110/22 kV substation in Horní Planá. The substation design addresses, for example, the issue of reducing the load of surrounding power lines from 110/22 kV substations, reducing the size of short-circuit ratios in the surrounding system, reliability and continuity of supply, etc. Furthermore, loads of individual outgoing feeders from the surrounding substations are analyzed, in case they will be connected to a new substation. Following this, the work also addresses the related new decay points of the lines, which are determined by calculation and simulation in the Grizzly program. The simulation results could be used to compare the current load status of individual lines and contribute to the assessment of the possible benefits of both the new substation and the implementation of other modern technologies for faster and more efficient measurement and handling during operating and fault conditions.
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Design of placing high voltage electrodes of the projection set of electron microscope on insulating rods
Pavlas, Ondřej ; Musil, Vladislav (referee) ; Hejátková, Edita (advisor)
In it´s first part, this presented master´s thesis focuses on the problematics of actions taking place in dielectric materials and phenomenons on the surface of real insulators placed in electric field. This research is followed by selection and rating of appropriate ceramic materials for the actual design of the metal – ceramic assembly. The greatest emphasis is given to design of the optimal configuration of the insulator and electrode, which is supported by simulations from the software that implements finite element method. Eventually, the high voltage tests of the assembly used for measuring leakage currents are performed.
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High-Voltage Structures for Galvanic Isolation in Integrated Circuits
Ptáček, Karel ; Husák, Miroslav (referee) ; Zemánek, Miroslav (referee) ; Boušek, Jaroslav (advisor)
Tato dizertační práce představuje novou techniku laterární rezonanční vazby, která je využita v návrhu galvanicky izolovaného posouvače úrovně, který je následně implementován v 800 V půlmůstkovém kontroléru pro průmyslové aplikace. Ve srovnání s tradičními galvanickými izolátory jsou výrobní náklady tohoto řešení nižší. Pro aplikace vyžadující vyšší úroveň galvanické izolace je popsán následný vývoj galvanicky izolovaného posouvače úrovně, který využívá pouze jeden galvanicky oddělený posouvač úrovní pro komunikaci v obou směrech, což výrazně snižuje plochu struktury izolátoru. Jako součást následného návrhu je představen galvanický izolátor který je schopen přenášet analogovou hodnotu napětí. Analogový izolátor byl testován v reálné aplikaci síťového spínaného zdroje jako náhrada standardního optočlenu. Tato konstrukce umožňuje integraci primárních a sekundárních obvodů v jednom pouzdře, což umožní snížit složitost a cenu spínaného zdroje.
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Singing Arc
Kovaříková, Lucie
This work discusses about the determination and the constuction of plasma speaker. The aim is to describe the function and the manufacture process. Plasma speaker operates on the principle of the electric discharge between two electrodes of voltage transformer. Changing the current through the arc influences the temperature around the arc. Because of the changing temperature, the pressure around the arc changes too. This phenomenon creates sound waves.
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Development of voltage instrument transformer resistible against higher harmonics
Mihályi, Róbert ; Odehnal, Martin (referee) ; Bušov, Bohuslav (advisor)
This bachelor's thesis describes the basic principles of transformer operation in the first part. The following chapters focus on issue of higher harmonic frequencies. Then it describes the basic design and principles of instrument transformers, which are the main subject of this work. At present, higher harmonic frequencies are becoming more and more common in electrical networks. Therefore, this work tries to bring new knowledge in the issue of higher harmonic frequencies in instrument transformers. The last chapters describe the computational design of an instrument transformer that resists higher harmonic frequencies. This transformer must be able to transfer these frequencies to the secondary winding. It was necessary to study the standards and technical literature related to this topic in order to create the proposal.
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