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Project of Photovoltaic Power Plant Grid Connection
Blažek, Tomáš ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This bachelors thesis deals with photovoltaic technology and economic evaluation of used technology equipment. The first part describes the technology for extraction of power from photovoltaic sources - transformer 22/0,4kV and its basic parts. Then there is the calculation of the amount of openings for cooling the transformer according to ČSN 33 3240. The second part focuses on the description of the major part of the photovoltaic plant. Here are divided solar panels on the material from which they are produced and the type of installation in the field. Next is describe the types of inverters, their principles and functions. The last part compares the different types of transformers and operating costs over the lifetime of plants (20 years), are described factors for proper selection of inverters and solar panels.
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Independent Traction Drive with Low-Voltage Induction Machine
Matucha, Tomáš ; Skalický, Jiří (advisor)
This work deals with creation of an exact mathematical model of a traction drive with low-voltage induction machine (28 V) which is fed from accumulators. This model was developed in MATLAB – Simulink and consists of induction machine model, inverter model and load model. Vector Control was added to models connected together. This complex model allows considering many effects into simulations. These effects are commonly neglected, although they have significant influence on drive behaviour, especially by using low-voltage machine. It is impact of magnetic circuit saturation, impact of temperature and skin effect on winding resistance, impact of inverter nonlinearities such as on-state voltage drops on switching elements, dead times and transistors switching times. The attention was paid to determination of losses in drive parts. The correctness of the model was verified at laboratory workplace established for this purpose. The laboratory drive can be controlled by a microprocessor or by using MATLAB and dSPACE application. The influence of compensations of inverter nonlinearities and DC-link voltage ripple on higher harmonics of inverter output currents was analyzed. Furthermore, the control, which decreased resistive losses, was solved.
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Frequency inverter for small induction machine
Pavlík, Ondřej ; Procházka, Petr (referee) ; Červinka, Dalibor (advisor)
The aim of this diploma thesis is to continue in prototype realization and a final proposition of three-phase frequency transformer pilot projected in scope of my bachelor work. This transformer is outlined for a small unsynchronized engine to 100 watt output and is designed to supply the fan motor. This suggestion was optimalized from the standpoint of bargain low price and technical feasibility. Powerful part of transformer is solved with help of circuit FSB50450 which is fed from compact source MYRRA 47155. Steering system is guaranteed with circuit MC3PHAC. This device is possible to use in less demanding applications where it was resisted by high expensive price of common frequency transformers.
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Operation of a distribution system with resistance welders
Zelený, Miroslav ; Šlezingr, Jan (referee) ; Drápela, Jiří (advisor)
This Diploma thesis deals with assessment of the influence of two fundamental types of resistance welders operation on chosen power quality parameters at the point of common coupling (PCC) of the power network. The assessed parameters of power quality are the total harmonic distortion of the supply voltage, asymmetry of the supply voltage and the level of short term flicker at the point of common coupling. The assessment is based on the comparison of the results of computer simulations done in PSCad 4.2.0 with the requirements of technical standards. The outcome of this thesis is the determination of allowable limits for physical and operation parameters for the general arrangement of a power distribution network and a resistance welder that should guarantee the power quality compliance.
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Characteristic of photovoltaic system
Pokorný, Marek ; Dolenský, Jan (referee) ; Vaněk, Jiří (advisor)
The aim of this work is informed first about photovoltaics universally, works to inform the photovoltaic panels and complete plants. The work also includes instructions on how to implement PVP in accordance with law. Another part is the rough draft of the photovoltaic power 30 kWp, which can be placed on the house, computation and calculation of investment and them profitable investments to time. Design is made in two separate forms of the Fronius Solar and Sunny Design, their outputs are compared. The practical part of this work cooperates with the company SOLARTEC Ltd. for experimental measurements of the photovoltaic system and develop a methodology for setting the properties of real solar systems in operation from the measured data then stored in a database. These data further evaluate and compare the similar operating conditions. This data will show as the course of production of electricity during the typical day in percentage terms, depending on the incident irradiance, cell temperature, angle of incident radiation, etc. We can compare what it looks like an ideal day in terms of production of photovoltaic power, with the other days. Further are in work mentioned histograms achievement panel behind classical day and behind all - time investigation.
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Inverter 12V DC/230V AC
Stejskal, Jiří ; Huták, Petr (referee) ; Klíma, Bohumil (advisor)
This diploma thesis describes particular parts of power inverter such as gate driver, DSC, LC filter, low power supply, DC/DC converter and four-quadrant bridge and manner of its control by digital signal controller. Inverter is designated for generating of a mobile artificial electric grid (for example in a car).
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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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Auxiliary power sources in electric traction
Kuzdas, Jan ; Procházka, Petr (referee) ; Červinka, Dalibor (advisor)
The purpose of this thesis is proposal of auxiliary power sources in electric traction. Specifically we deal with two converters. Both of them were used in traction vehicle's applications, which are developed by the Department of Power Electrical and Electronic Engineering, Brno University of Technology. First converter was used as a power supply in secondary traction mechanism of electric locomotive. Second one to power supply of dash board in automobile with fuel cells.
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Safe Uninterruptable Power Supply of Power Station Internal Consuption
Tomášek, Petr ; Přidal, Petr (referee) ; Orságová, Jaroslava (advisor)
This thesis examines issues connected to safe uninterruptible power supplies. The term safe uninterruptible power supply is used for an aggregate of devices providing power for appliances that participate in safe rapid shutdown of a power plant in case power from a usual source fails. The thesis is divided into two parts – theoretical and practical. Theoretical part deals with possibilities and ways of realizing an aggregation of safe uninterruptible power supply. Various devices that can appear in the section of a safe uninterruptible power supply are listed and each device is characterized. Appliances that can be provided for by the sources of safe uninterruptible power supply are mentioned as well. These appliances are listed in accordance with ČSN standard nr. 381120. The theoretical part concludes with new trends in realization of safe uninterruptible power supplies. One of these sources is a clean source technology that can also be implemented in various ways. Practical part contains a suggestion of a safe uninterruptible power supply for particular steam power plant. This suggested safe uninterruptible power supply consists of rectifiers, batteries, inverters and a dieselgenerator. Calculated parameters of each device at the conclusion of the practical part are followed by a diagram of the suggested section of safe uninterruptible power supply.
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Conveyor Inverter - Design Lifting Mechanism
Zálešák, Martin ; Kašpárek, Jaroslav (referee) ; Škopán, Miroslav (advisor)
I am concern with a proposal of conceptual solution of Conveyor Inverter in my bachelor work. This Conveyor Inverter is used for the change of the direction europallet about 90° between roller and chain conveyor according to given technical parameters. My bachelor work contains complete 3D proposal, constructional and functional solutions which are based on checking calculations. Lifting of the Conveyor Inverter is done using a leverage mechanism of electric motor.
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