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Investigation of carbon effect in negative active mass on lead-acid accumulator for HEV.
Tonar, Karel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The lead-acid bateries for hybrid-electric vehicle (HEV) working under high-rate partial-state-of-charge (HRPSoC) conditions. The negative plates of lead-acid batteries have low charge acceptance. The cycle life of the batteries is dependent on the rate accumulation of PbSO4 on the negative plates. Addition of some carbon or graphite forms to the negative paste mix improves the charge efficieny and slows down sulfation of the negative plates. The master’s thesis wants to explain the contribution of electrochemically active carbon (EAC) additives to the mechanis of the electrochemical reaction of charge of the negative plates.
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Investigation of temperature change in lead-acid accumulator for HEV
Tošer, Pavel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The oldest and also most used type of secondary cells is lead-acid accumulator. Basic functional principle stayed same as in foundation time, only operation parameters are still improving (for example one of the most important is lifetime). Significant technical problem is temperature of lead-acid battery and her influence on functionality and running reactions. Master thesis is focused on this section, when is necessary to evaluate new pieces of knowledge in development. The work deals with description existing types of accumulators, further deals with theory of temperature balance and in the end by measured datas and theirs analyzing.
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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.
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Computer analyse of LBIC pictures
Štencel, Jakub ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
This thesis is concerned with image picture analysis, especially with images obtained by diagnostic LBIC method. The individual defects occuring on solar cells are described in theoretical part, including methods which serve for making referential image. Furthermore, the creation of difference image is analysed, from whom the interferences will be evaluated. The aim of practical part is to focus on generation of algorithms which investigate the defects, and the description of application for program control is described in conclusion.
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Optimalization of tilt of photovoltaic module
Šindler, Roman ; Vaněk, Jiří (referee) ; Křivík, Petr (advisor)
This thesis deals with the solar radiation, which is one of the potential sources of the renewable energy. The purpose of this thesis is to apprise of the methods how to calculate the Sun’s position as well as to learn the basics of software VEE Pro 8.0. Also, create a program simulating the location of the Sun during the day according to the variable latitudes and days and consequently to calculate the Sun irradiation passing through the atmosphere onto the tilted solar module, considering the respective tilt. Theoretical part describes the transmition of the energy between Sun and Earth, global irradiation and its components, which are generated by beams passing through the atmosphere and incident on a solar module. Practical part is dedicated to a program creation according the theoretical basis and it is used for further simulation of the Sun’s position. Another program simulates the total daily and annual irradiation including its components onto the tilted solar module, considering the respective tilt.
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State of charge prediction of lead acid batteries
Chochola, Ondřej ; Bača, Petr (referee) ; Křivík, Petr (advisor)
The general aim of the thesis is a detailed examination of battery charging condition possibility of lead-acid accumulator with the help of pulse current method. The methodology consists of experimental cell testing by pulse battery charging and pulse battery discharging during a progressive change of charging and discharging current as well as charging and discharging time change. The testing procedure proceeds at a various battery charging condition. Principal aim of this work is to compare final voltage dependencies and to establish the usability of pulse current method to determine battery charging condition.
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Simulation of dielectric materials absorption characteristics
Bačkovský, Pavel ; Novák, Vítězslav (referee) ; Křivík, Petr (advisor)
This projects deal with dielectric materials. Characterize definition of dielectric and polarization of dielectric. Shows dielectric relaxation. Specified conception dielectric absorption and interpreted them with DC voltage charging condensator. However, this thesis be engaged in simulation of this process. Output is simulation program of dielectric absorption characteristics for two relaxation mechanism.
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Upgrade of testing workplace for solar cells
Řezníček, Martin ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
The master‘s thesis is focused on the modification of measurement workplace for solar cells. In the first part of the thesis are introduced general problems of the solar energy and possible use in the international power supply, the details about the photovoltaic effect, processing of solar cells and their subsequent parameters. More further in the text the autor is concerned with causes of solar cells defects formation and representation of the most important defects. For defects detection are known the detection methods of solar cells, which are generally described in the text. The second part of the thesis includes detailed description of the LBIC method and workplace both the VUT Brno, and in Solartec, Ltd. The most important point of this part is project and description of innovated workplace from hardware and software realization. There is out of print the function and the description of the user interface and subsequently there are mentioned results gained from original and innovated workplace. In the conclusion are summarized whole activities of the master’s thesis, described and evaluated achieved results and outlined the direction, where would the other development of the LBIC workplace on VUT Brno be proceeding.
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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.
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