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Design of high voltage source for electrical ageing of insulating mater
Příborský, Václav ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
Target of this thesis is analyse problems of dielectric materials ageing and environment characteristic applied by ageing process. Types of electric stress are comparing in this work, when and how they are working and how to eleminate them. Next aim is design the high voltage sinus transformer as source for measuring of electric stress and ageing dielectric materials. There is discuss about computer control and collecting of the output datas. In the end is source testing by practical measurement of some dielectric samples.
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Integration of Photovoltaic Power Plants in the Electricity System
Michl, Pavel ; Paar, Martin (referee) ; Mastný, Petr (advisor)
The thesis discuses an integration of photovoltaic power stations to electric network. The first part describes connecting conditions of small sources to distribution system, including administrative requirements, feasibility study, and requirements to the energy meters, measuring, control devices, switching devices and protection. The second part is aimed to describe problems of the photovoltaic system. Solar radiation generating and reducing of its intensity incident upon the earth surface are described in this part. The quantum of produced electric power depends on climatic conditions in the fixed area, seasons, etc. This work also discusses the types of photovoltaic cells and their actual efficiency. Inverters are further important components of the photovoltaic system. The parameters of the inverters have a great influence on the total actual efficiency of the photovoltaic system. Different methods of the photovoltaic panels’ connection with the inverters and their advantages and disadvantages are also mentioned. The supporting structure of the photovoltaic panels and eventually transformer are further important components of photovoltaic system. The work also analyze the methods of connection of the photovoltaic power station to distributive low voltage and medium voltage network, electric energy accumulation and possibilities of the sale of produced electric energy. The large number of the connected photovoltaic power stations has negative influences to electric network. The third part contains the design of a photovoltaic power plant with a capacity of 516,24 kWp on the scoped area in southern Bohemia. The project documentation for the location where the power plant is designed is also made. It contains the design of photovoltaic panels, the design of the inverters to get an optimal power load. This part also contains a calculation of the photovoltaic system losses and the design of transformer and the cable junction calculation of the distributive system. The feasibility study of the power plant connected to distributive system is also conducted. Its delivery rate will be connected to the distribution point Řípov (110/22 kV). The calculation results show us that this photovoltaic power plant can be linked to the distribution system. The final part of this paper contains an economic estimate of the photovoltaic power plant operating and the calculation of the return. An Economic return is influenced by the wide range of values that affect the total return rate. The calculation of an operating economy is made for several variants. The return rate in refer to contemporary redemption price for 2010 with no consideration for a bank loan is 7 years. If we consider the bank loan it would be 12 years. The penetrative reduction of the redemption price is expected for 2011. Calculation works with the decline of 30 %. It would extend the rate of return to 11 years without a bank loan or to 22 years with the bank loan. The bank loan is considered to cover 80 % of the investment.
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Utilization of ANSYS Workbench program at power electrical engineering
Partl, Tomáš ; Aubrecht, Vladimír (referee) ; Kuchyňková, Hana (advisor)
In its first part this Master´s thesis describes creation of electronic database design in Raster Design 2009 program as an effective form of storage only for paper documentation. The second part of my thesis provides calculation of primary and secondary winding of current instrument transformer of over-current conduit through the winding and influence on other parts of transformer i.e. error of transformer or increasing magnetic induction core and others. The last third part is focusing on usage of ANSYS Workbench in power electrical engineering. The thesis shows specific example of warming of current instrument transformer (thermal analysis) and comparing the results with theoretical (calculated) values.
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Project of Outgoing Transformer Unit for the Photovoltaic Power Station
Hanák, Miroslav ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This master’s thesis engages in project of outgoing transformer unit for the photovoltaic power station. It describes project and its design documentation what conducts to practising of construction. It has compared investing to more expansive transformer what has lower loss. It describes charges of operation’s transformer in twenty years. It leads project of cable low voltage. It compares whether is better to use aluminium or cupric cables. Project is led with respect for investment costs and minimum of operation loss.
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110/22 kV Transforming Substation Reconstruction
Kubiš, Petr ; Bátora, Branislav (referee) ; Macháček, Jan (advisor)
This thesis deals with the issue of reconstruction 110/22kV distribution substation in economic point of view, where we will assess the benefits of a combination of their involvement using the discounted cost. It’s necessary to reconstruct distribution substation due to the increasing demand for electricity, upgrading equipment in the distribution systems, improve the reliability of electricity supply to customers, etc.. Distribution substation layout must meet conditions resulting from a law on energetics and operation of primary distribution networks.
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Short Circuit Currents in the Sokolnice 400 kV Switching Station with Direct 400/110 kV Transformation Applied
Vojtěch, Pavel ; Špaček, Jaroslav (referee) ; Blažek, Vladimír (advisor)
The destination of this Bachelor´s Thesis is to explore short circuit currents for voltage level 400 kV in the switching station Sokolnice before year 1995 and after this year, when came to installation of the convertor T402 and to voltage direct 400/110 kV transformation applied. The Thesis is detecting at relation as for three-phase short circuit do for single-phase short circuits, for 400/220/110 kV primary transformation variation in voltage and for variation 400/110 kV, the change which came after connection of the convertor T402. In base of this calculation will be explored the short circuit resistance rating switching station in agreement with parameters ordered by the comp. Inc. ČEZ Prague.
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Electrotherapy
Slavíček, Milan ; Rampl, Ivan (referee) ; Chmelař, Milan (advisor)
Aim those work is suggest simple generator for electropathy. In exordium deal with features weaving and fission current used in the electrotherapy. Draft part then includes proposal single part generator and calculations needed to achievement purposes. Result is then diagram simple generator for production Träbert flows and list parts.
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Description Methods for Electrical Systems and Their Solving
Křižka, Jakub ; Němec, Zdeněk (referee) ; Šeda, Miloš (advisor)
The objective of bachelor thesis is a searching description of methods, which are usually used for calculation of circuit variable values in electric circuits. At the beginning is thesis concerning with description of individual components (power supplies, electronic components) used in electric circuits, then also with analysis of rules, which are the fundamental for a calculation of values in electronic circuit – Ohm’s rule and Kirchhoff’s rules. Indivisible part of thesis is also summary of special methods, such as method of loop currents (mesh analysis), method of nodal voltage (nodal analysis) etc. and their demonstration on examples of electric circuits. The structure of thesis is coursebook and gives successive summary of information in area calculations of electric circuits.
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The electrostimulation the spermiation in the crayfish
KUBEC, Jan
The crayfish are important and indispensable animals in aquaculture. In the aquatic environment, they have a role as predators, food for other fish, detrivors and they are an important element in the circulation of the energy and the nutrient in the aquatic ecosystem. Today, number of the european crayfish species populations is decreasing. It is caused by unfavourable regulation of streams, water pollution and the occurence of crayfish plague. The main purpose of present study was examining the impact of electrostimulation on the males of the crayfish and obtaining sex products (the sperm). The principle of this research was determining whether the male of crayfish are able to extrude spermatophore with sperm by an electric stimulus. The transformer was used as resource alternating current in experiments. All experiments conducted in a laboratory of experimental device for fish farming in Vodňany. Experiments were conducted in 2011 on a male of the spiny-cheek crayfish (Orconectes limosus), the signal crayfish (Pacifastacus leniusculus) and the red swamp crayfish (Procambarus clarkii). The results of this work and success of the experiments suggest, that electrostimulation could be used for obtaining sex products (the sperm) from crayfish males. Results from a laboratory of electron microscopy confirm the harmlessness of electrostimulation on the shape and structure of sperm. The sperm can be used to artifical insemination of the crayfish eggs in future. However, sperm capacitation is problematic.
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Problems and measurements of the basic electrotechnical quantities
BOHÁČ, Radek
The purpose of this thesis is selection and specification of basic teaching methods used in heavy current laboratory during vocational training education at secondary school. Basic methods for electrical values measurements in heavy-current laboratory, measuring instruments basic division and measured electrical values evaluation. Further, basic measurement of electrical values, current, voltage, power, resistance and capacity are specified here.
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