|
|
Optimization of use properties Lead-Acid batteries
Lábus, Radek ; Dostál, Zdeněk (referee) ; Jareš, Petr (referee) ; Křivík, Petr (advisor)
This thesis focuses on the limitations of degradation mechanisms of Lead-Acid batteries, which significantly contributes unequal distribution of current (and therefore internal resistance, charge passed and power loss) on the surface of the electrodes of Lead-Acid battery. The unevenness of distribution of these parameters significantly influences the distribution of current tabs on the electrodes. In this work it was developed realistic model of Lead-Acid battery cell with plate electrodes with different variants of the distribution of current tabs. Measured results obtained in this model were compared with the results found out from the mathematical simulations. Through these simulations, it was possible to take a look deeply into the processes and changes in the electrodes of Lead-Acid batteries during discharge. Goal of this work was for predefined variants of positioning of the current tabs to simulate distribution of current, internal resistance, charge passed and power loss during discharge. Another goal was to compare the different variants and to find the optimal variant of current tabs positioning based on minimizing of unevenness of examined variables distribution.
|
|
|
Computer as an Intelligent Partner in the Word-Association Game Codenames
Jareš, Petr ; Fajčík, Martin (referee) ; Smrž, Pavel (advisor)
This thesis solves a determination of semantic similarity between words. For this task is used a combination of predictive model fastText and count based method Pointwise Mutual Information. Thesis describes a system which utilizes semantic models for ability to substitue a player in a word association game Codenames. The system has implemented game strategy enabling use of context information from the game progression to benefit his own team. The system is able to substitue a player in both team roles.
|
|
|
Causes of Premature Capacity Loss of Lead-Acid Accumulators Operating in PSoC Mode in Hybrid Electric Vehicles
Bilko, Radek ; Jareš, Petr (referee) ; Dostál, Zdeněk (referee) ; Bača, Petr (advisor)
This thesis is completion of whole stage of researches and it is a result of existing need of increase efficiency, utilization rate and service life of lead acid batteries VRLA planned for utilization in hybrid electric vehicles in mode of partial state-of-charge PSoC. During the application of mode PSoC at lead acid battery occurs irreversible sulfation of negative electrodes and thus to loss their charging capability. This phenomenon, according to the latest trend called PCL3, isn´t connected with subsequently referred effects PCL1, PCL2, show up on positive electrodes. Result of this thesis is finding a new types of additives, determine their optimum amount and size in such a way that innovated composition of negative active materials be able to resist sulfation of negative electrode during operation in mode PSoC. Part of the effort to clarify actions ongoing on negative active material and causes non-returnable sulfation electrodes is also monitoring of structural changes electrode active material by using environmental scanning electron microscope, which helped to clarify processes related with loss of capacity in mode PSoC. Special attention during reserches was focused on study of the properties contact layers between collector and electrodes active material and itself active materials lead-acid battery druring exploitation. There were gain new information about influence repeated cycling of (charging, discharging) the critical area of the electrodes. Measurements was carried out on specially prepared experimental electrodes DC Difference Method, this enabled obtain data in situ.
|
|
|
Impedance Measurement of Lead-acid Accumulator
Abraham, Pavel ; Dostál, Zdeněk (referee) ; Jareš, Petr (referee) ; Bača, Petr (advisor)
This dissertation deals with impedance measurements of lead-acid accumulator. Main aim was to study recent problems of impedance measurements of lead-acid accumulator and most importantly to extend difference method and also to interpret its results. The original DC difference method was developed earlier at our Power Sources Laboratory of Department of Electrical and Electronic Technology. The DC difference method and also the new AC difference method are both non-destructive, which means that experimental data can be obtained in situ. New method provides more accurate set of information because of its wide frequency range nature. Electrodes of lead-acid accumulator were analysed with special attention to collector / active mass double layer and to active mass itself. Various states and operation regimes were investigated. Obtained data contributed to better understanding of involved degradation mechanisms. Main aim of other experiment was to observe and interpret corrosion rates of electrode collector composed of various lead alloys. Last but not least charge and discharge regimes e.g. 100% deep of discharge regime, partial state of charge (PSoC) regime and pulse charge regime were analysed. BioLogic VSP was the device used for almost all experimental measurements. It takes a lot of effort to optimise VSP operation regime. Best operation regime of VSP for the difference method was suggested too.
|
|
|
Fast Adaptation of Codenames Computer Assistant for New Languages
Jareš, Petr ; Otrusina, Lubomír (referee) ; Smrž, Pavel (advisor)
This thesis extends a system of an artificial player of a word-association game Codenames to easy addition of support for new languages. The system is able to play Codenames in roles as a guessing player, a clue giver or, by their combination a Duet version player. For analysis of different languages a neural toolkit Stanza was used, which is language independent and enables automated processing of many languages. It was mainly about lemmatization and part of speech tagging for selection of clues in the game. For evaluation of word associations were several models tested, where the best results had a method Pointwise Mutual Information and predictive model fastText. The system supports playing Codenames in 36 languages comprising 8 different alphabets.
|
|
|
Fast Adaptation of Codenames Computer Assistant for New Languages
Jareš, Petr ; Otrusina, Lubomír (referee) ; Smrž, Pavel (advisor)
This thesis extends a system of an artificial player of a word-association game Codenames to easy addition of support for new languages. The system is able to play Codenames in roles as a guessing player, a clue giver or, by their combination a Duet version player. For analysis of different languages a neural toolkit Stanza was used, which is language independent and enables automated processing of many languages. It was mainly about lemmatization and part of speech tagging for selection of clues in the game. For evaluation of word associations were several models tested, where the best results had a method Pointwise Mutual Information and predictive model fastText. The system supports playing Codenames in 36 languages comprising 8 different alphabets.
|
|
|
Computer as an Intelligent Partner in the Word-Association Game Codenames
Jareš, Petr ; Fajčík, Martin (referee) ; Smrž, Pavel (advisor)
This thesis solves a determination of semantic similarity between words. For this task is used a combination of predictive model fastText and count based method Pointwise Mutual Information. Thesis describes a system which utilizes semantic models for ability to substitue a player in a word association game Codenames. The system has implemented game strategy enabling use of context information from the game progression to benefit his own team. The system is able to substitue a player in both team roles.
|
|
|
Optimization of use properties Lead-Acid batteries
Lábus, Radek ; Dostál, Zdeněk (referee) ; Jareš, Petr (referee) ; Křivík, Petr (advisor)
This thesis focuses on the limitations of degradation mechanisms of Lead-Acid batteries, which significantly contributes unequal distribution of current (and therefore internal resistance, charge passed and power loss) on the surface of the electrodes of Lead-Acid battery. The unevenness of distribution of these parameters significantly influences the distribution of current tabs on the electrodes. In this work it was developed realistic model of Lead-Acid battery cell with plate electrodes with different variants of the distribution of current tabs. Measured results obtained in this model were compared with the results found out from the mathematical simulations. Through these simulations, it was possible to take a look deeply into the processes and changes in the electrodes of Lead-Acid batteries during discharge. Goal of this work was for predefined variants of positioning of the current tabs to simulate distribution of current, internal resistance, charge passed and power loss during discharge. Another goal was to compare the different variants and to find the optimal variant of current tabs positioning based on minimizing of unevenness of examined variables distribution.
|
|
|
Causes of Premature Capacity Loss of Lead-Acid Accumulators Operating in PSoC Mode in Hybrid Electric Vehicles
Bilko, Radek ; Jareš, Petr (referee) ; Dostál, Zdeněk (referee) ; Bača, Petr (advisor)
This thesis is completion of whole stage of researches and it is a result of existing need of increase efficiency, utilization rate and service life of lead acid batteries VRLA planned for utilization in hybrid electric vehicles in mode of partial state-of-charge PSoC. During the application of mode PSoC at lead acid battery occurs irreversible sulfation of negative electrodes and thus to loss their charging capability. This phenomenon, according to the latest trend called PCL3, isn´t connected with subsequently referred effects PCL1, PCL2, show up on positive electrodes. Result of this thesis is finding a new types of additives, determine their optimum amount and size in such a way that innovated composition of negative active materials be able to resist sulfation of negative electrode during operation in mode PSoC. Part of the effort to clarify actions ongoing on negative active material and causes non-returnable sulfation electrodes is also monitoring of structural changes electrode active material by using environmental scanning electron microscope, which helped to clarify processes related with loss of capacity in mode PSoC. Special attention during reserches was focused on study of the properties contact layers between collector and electrodes active material and itself active materials lead-acid battery druring exploitation. There were gain new information about influence repeated cycling of (charging, discharging) the critical area of the electrodes. Measurements was carried out on specially prepared experimental electrodes DC Difference Method, this enabled obtain data in situ.
|
|
|
Impedance Measurement of Lead-acid Accumulator
Abraham, Pavel ; Dostál, Zdeněk (referee) ; Jareš, Petr (referee) ; Bača, Petr (advisor)
This dissertation deals with impedance measurements of lead-acid accumulator. Main aim was to study recent problems of impedance measurements of lead-acid accumulator and most importantly to extend difference method and also to interpret its results. The original DC difference method was developed earlier at our Power Sources Laboratory of Department of Electrical and Electronic Technology. The DC difference method and also the new AC difference method are both non-destructive, which means that experimental data can be obtained in situ. New method provides more accurate set of information because of its wide frequency range nature. Electrodes of lead-acid accumulator were analysed with special attention to collector / active mass double layer and to active mass itself. Various states and operation regimes were investigated. Obtained data contributed to better understanding of involved degradation mechanisms. Main aim of other experiment was to observe and interpret corrosion rates of electrode collector composed of various lead alloys. Last but not least charge and discharge regimes e.g. 100% deep of discharge regime, partial state of charge (PSoC) regime and pulse charge regime were analysed. BioLogic VSP was the device used for almost all experimental measurements. It takes a lot of effort to optimise VSP operation regime. Best operation regime of VSP for the difference method was suggested too.
|
guest ::
