|
|
Influence of the pulse charge on properties of the lead acid batteries
Zbožínek, Štěpán ; Vaculík, Sebastian (referee) ; Křivík, Petr (advisor)
The presented master´s thesis deals with lead-acid batteries and methods of their charging. First part shortly describes the problems of lead-acid batteries. There are introduced common principles, type of construction and requirements, that should be complied with lead-acid batteries. Following part discusses the basic characteristics of charging. There is given a detailed description of current pulse charging method, on which is also mainly focused this master´s thesis. For this charging method, several basic experiments were done in order to verify functionality of the measuring device, software, the tested cells and primarily to verify charging modes. The goal of this thesis is to find out suitable mode of pulse charging, which would be fast as well as tested cells-friendly. The conclusion of this master´s thesis contains a resume of acquired theoretical knowledge and an evaluation of measured results, on which was the appropriate charging mode proposed.
|
|
|
Functional blocks for the development of autonomous photovoltaic system
Ovesný, Karel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The project considers realization system, which will allow us to test six different operation modes on lifetime accumulators. The system will link to computer, which will execute measurement current and tension and switch betwencharging and discharging modes. The measured values will record in someone time intervals in to computer memory. After someone time will analise these measured valuer and will provide optional operation mode.
|
|
|
Different way how to use solar radiation for the electric energy production
Obadal, Petr ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
The thesis deals with the problem of potential use of solar energy through the conversion into electric energy. The thesis analyses in great detail several types of conversion. My special concern included photovoltaic conversion and thermal conversion of solar energy using steam turbines for energy production. In the subsequent parts, I focus on the problem of photovoltaic, photovoltaic systems, and solar thermal power plants, their installation and use.
|
|
|
Charging of lead-acid accumulator by pulse current
Jurčák, Tomáš ; Vaněk, Jiří (referee) ; Křivík, Petr (advisor)
Most used and oldest secondary current source is lead-acid battery. This bachelor´s thesis provides short introduction to lead-acid batteries, to their distribution, structure, chemical reaction inside lead-acid battery and negative effects on battery. Next part is focused on charging of lead-acid battery, here is shortly described few types of charging with emphasis on pulse charging. Last part is focused on construction of experimental electrode and experiments with pulse charging.
|
|
| |
|
| |
|
|
V-I characteristic of solar cells
Kaderka, Tomasz ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
The theoretical part is to outline the possibilities of solar energy conversion, learn about the issues solar cells and describe the history of photovoltaics and photovoltaic energy conversion. Then describe principle of the measurement VA characteristics of photovoltaic cells. This issue is not as easy as it seems at first sight, because the solar cell isn’t a linear component, which is very easy to measure. Analysis of VA characteristic of photovoltaic cells affects parameters such as: light intensity, temperature, serial and parallel resistance, the slope of the light source, and more. The practical part deals with creating a workplace for automatic measurement of VA characteristics of photovoltaic cells in the LabVIEW. Challenge is to create a functional program, which automatically measures the VA characteristics not only in the lighted cells, but also in the shaded cell (diode mode). The program calculates the power and important parameters, such as short-circuit current, open circuit voltage, maximum power, current and voltage at maximum power article. The program allows you to export the measured values to a text file. In the last chapter of this work is made control measurements of three samples of monocrystal photovoltaic cell by the measuring workplace. The measurement is compared with the reference device Solar Cell Tester.
|
|
|
Influence of shading on I-V characteristics of photovoltaic modules
Hájek, Tomáš ; Vaněk, Jiří (referee) ; Křivík, Petr (advisor)
The presented thesis is concerned with the principles of Photovoltaics. It describes the basic principles of photovoltaic panels functioning and the unique periods of their developement. The thesis is also focused on the theoretical knowledge of equivalent circuits of photovoltaic panels. The primary objective of the thesis is a project of simulation environment in the programme Agilent VEE Pro 8.0. The programme enables a simulation of I-U characteristics of real photovoltaic panels.
|
|
|
Analysis of thermal processes inside of lead acid battery cell
Starý, Viktor ; Vaněk, Jiří (referee) ; Křivík, Petr (advisor)
Lead-acid battery is one of the most widely used electrochemical cells. These batteries have been associated with supplying energy to start the car. Currently used for propulsion and the overall operation of hybrid electric vehicles. When operating lead-acid batteries are made inside cell the thermal happens. The thermal going generate heat caused by chemical reactions during charging and discharging of the electrochemical system, the heat generated by ohmic and polarization losses and heat mediated contact with the environment. In this diploma thesis shows the principle of lead-acid battery and thermal processes that take places in the accumulator during its operation.
|
|
|
Degradation test of polymer material in the high electric fields
Martynek, Aleš ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
This document includes methods of testing and measuring of the protective layers used in solar panels with crystallic solar cells. The main emphasis here is placed on the degradation of these materials due to exposure to strong electric field. Main point of diploma thesis is evovle an experimental workplace for electric aging of dielectric materials and monitor changes of material properties. Final knowledges are then analysed with the climate degradation tests. Tested samples were prepared in cooperation with Solartec s.r.o.
|
guest ::
