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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.
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Influence of skin effect, proximity effect and air gap on winding losses of HF inductors and transformers
Pitner, Tomáš ; Cipín, Radoslav (referee) ; Martiš, Jan (advisor)
The bachelor's thesis deals with power losses in the windings of high-frequency inductors and transformers. A detailed mathematical and qualitative analysis of the skin effect, proximity effect and leakage flux of air gap is performed, supplemented with the results of computer simulations using the finite element method. The thesis introduces analytical and numerical methods for calculating power losses in the windings of inductors and transformers and describes suitable measurement methods, which are further used in the thesis. For selected geometries of inductors and transformers, AC resistances of their windings are calculated using FEM and the results are compared with measurements on constructed prototypes. The winding geometries are also compared between each other.
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Influence of skin effect, proximity effect and air gap on winding losses of HF inductors and transformers
Pitner, Tomáš ; Cipín, Radoslav (referee) ; Martiš, Jan (advisor)
The bachelor's thesis deals with power losses in the windings of high-frequency inductors and transformers. A detailed mathematical and qualitative analysis of the skin effect, proximity effect and leakage flux of air gap is performed, supplemented with the results of computer simulations using the finite element method. The thesis introduces analytical and numerical methods for calculating power losses in the windings of inductors and transformers and describes suitable measurement methods, which are further used in the thesis. For selected geometries of inductors and transformers, AC resistances of their windings are calculated using FEM and the results are compared with measurements on constructed prototypes. The winding geometries are also compared between each other.
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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.
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