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Stabilized operation and short - circuit conditions within E.ON 110 kV power network supplied from Slavětice 110 kV switching station, during the period of 2011
Nábělek, Ondřej ; Rampl, Martin (referee) ; Blažek, Vladimír (advisor)
In the Master Thesis discusses the impact of the bridge connecting the transformer to power system connection to a separate transformers. They were first analyzed the method of calculating the steady operation of the network using the Newton iterative method and the method of calculating short-circuit ratios. It describes the area Slavětice 110kV substation, which is the subject of subsequent calculations. It is also elucidating the function of the bridge connection, advantages and disadvantages. The reason for implementing the bridge operation is to increase the reliability of electricity supply to customers but the major disadvantage is the greater technical and economic performance because increased short circuit current and the need for transmission transformer 400/110kV same type with the same parameters. Point is the practical part, which contains already concrete results taken with the dispatcher software Sinaut. There is a short-circuit resistance compared to short-circuit power substation, then the burden of the elements (transformers, lines) for two specified connection alternatives and four interruptions important elements. Finally, it stated that it can be done with the bridge connection which technical measures. It was discovered that in terms of short-circuit ratios in the present time it is not possible to operate the bridge connection transformers substation Slavětice 110kV and in terms of very different parameters of transformers 400/110kV the operation is not recommended.
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The inverter for arc-welding
Vaculík, Josef ; Klíma, Bohumil (referee) ; Červinka, Dalibor (advisor)
This diplom thesis theoretically deals about principle of pulse welding current source. Work explains operation principle of the single acting transmit converter used in realized construction and mention the others examples of converters types. Goal of the work is design individual parts of source : input filter, pulse transformer, output inductor and power semiconductors components. Thesis also contains description of the regulation circuitry of the converter, auxiliary power supply and pre-driver for power transistors. If everything will be all right prototype of the source will be assembled and measured. Results will be compared with theoretical assumptions.
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Magnetic fields for biomedical experiments
Otýpka, Jan ; Cipín, Radoslav (referee) ; Patočka, Miroslav (advisor)
In this work deals with magnetic fields for use in biomedicine. This solution involves the choice of the correct geometric arrangement of coils for generating magnetic field with a homogeneous distribution of magnetic induction of the widest possible area. The paper compares thre traditional types of coils, solenoid, toroid and Helmholtz coil. For Helmholtz and solenoid coil and is then carried out an analysis of the magnetic flux density in the inner space. Next part is devoted to electrical resonance in the LC circuit. This is then utilized for the development of pulsed magnetic field in the Helmholtz coil. It summarizes the theoretical and practical knowledge to design and construction of resonant converters. The end is devoted to the measurement of circuit parameters and verification of theoretical knowledge.
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Measurement and analysis of single-phase transformer
Princ, Pavel ; Huzlík, Rostislav (referee) ; Vítek, Ondřej (advisor)
The aim of that diploma thesis is low power transformer simulation via its substitutitional circuitry.As Instrument for matematical description of model and simulation of various operating situations with different amplitude and types of load was used Labview software. The software was simultaneously used for real transformer measurement and to compare these results with calculated values. The created program is also applied for measuring excercise for students. In The thesis is described measured transformer in terms of final elements method in FEMM software and there is showed the procedure of its design.
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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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