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Investigation pressure effect on lead-acid accumulator lifetime for hybrid electric vehicles.
Kulhány, Andrej ; Bilko, Radek (referee) ; Bača, Petr (advisor)
The thesis is focused on remitting lead-acid segments of partial charge mode which simulates the conditions in HEV. The experimental cells were submitted to different pressures on the electrode system. The main aim of the thesis was to minimize the irreversible sulphating of the negative electrodes, which are in the PSoC regime limiting in the overall life of lead-acid accumulators. All cells were submitted to measurement of the negative electrode potentials, resistance of active materials, contact resistance of the grid – the active material and measurements of pressure changes during three PSoC cycles.
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Investigation causes of the premature capacity loss in accumulator for hybrid electric vehicles
Vystrčil, Marek ; Bilko, Radek (referee) ; Bača, Petr (advisor)
This thesis describes the results of two successive experiments. The first was focused on the influence of impurities in the active mass of negative electrode in PSoC (Partial State of Charge) mode, which simulates the conditions occurring in HEV (hybrid electric vehicle). In the second experiment, cells with the same additives were exposed to optimum downforce 4N/cm2, by which we wanted to prove the influence of pressure on life of VRLA (Valve Regulated Lead Acid) cells working in operating HEV conditions.
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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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Investigation size effect of negative active mass additive on service life lead-acid accumulator.
Mikoláš, Jiří ; Novák, Vítězslav (referee) ; Bača, Petr (advisor)
The task of research work is to study new mechanisms and to minimize disturbance of lead batteries for hybrid electric vehicles. Those arising under the PSoC (Partial State of Charge) and is linked to irreversible sulphation mainly negative electrodes. As one solution to prevent sulphation of the negative electrode appears to be the active ingredients in a negative matter. In the investigated electrodes is verified the influence of carbon, titanium dioxide and silica on the grain size of the order of nanometers.
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The equipment for control very low temperatures during the detection defects of solar cells
Stojan, Radek ; Bača, Petr (referee) ; Vaněk, Jiří (advisor)
This work deals with measuring of very low temperatures during the detection defects of solar cells by photoluminescence method. Liquid nitrogen is used to cooling solar cells. Properties of liquid nitrogen and safety of handling are described in this work. Themperature in cryo area is measured by the thermocouple senzors. A main part of this work was to concept and creation of equipment for themperature controling in cryo technique. This equipment signalling danger scorch in low temperatures. The device was created to complement work place for the detection defects of solar cells by photoluminescence method.
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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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Modification of measurement workplace for solar cells
Roček, Radovan ; Bača, Petr (referee) ; Vaněk, Jiří (advisor)
The problems of solar cells are described in general in theoretic part of the master’s thesis. In particular there is described structure of solar cells, procedure of production of solar cells, kinds of defects that can occur in solar cells and diagnostic methods of detection of this defects. The solar simulator, electroluminescence method, detection of defects during microplasma shining, LBIV and LBIC method belongs to category of diagnostic methods. The main focusing is on diagnostic method of LBIC (Light Beam Inducted Current). The workplace which exploits this method is used in laboratory in Department of Electrotechnology on University of Technology Brno. This method is very exact and it reveals most of defects in solar cell but the problem is the slow speed of testing. In practical part of the master’s thesis the main solved problem is the proposition and realization of modified workplace of LBIC that would work on more modern level, it means using performer PC for service program and Agilent 34410A the modern measuring device. The speed up of the testing time is the goal of modernization in existing accuracy of finding. The modify workplace is realized and compared with the existing workplace subsequently.
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Development control programme for autonomous fotovoltaic system
Janáč, Stanislav ; Vaněk, Jiří (referee) ; Bača, Petr (advisor)
The project considers realization system, which allows us to test six different operation modes on lifetime of accumulators. The system will be connected to computer, that will perform measurement of current and voltage and switch betwen charge and discharge modes. The measured values will be recorded in certain time intervals to computer memory. After some time these measured data will be analised and the most optimal operational mode will be set.
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