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Measuring the Parameters of Piezo Energy Harvesters
Kunz, Jan ; Novák,, Martin (referee) ; Hadaš, Zdeněk (referee) ; Beneš, Petr (advisor)
This dissertation deals with the measurement of piezoenergy harvester parameters, in particular the measurement of their efficiency. The first part of the thesis summarizes important metrics for their comparison and reviews existing measurement systems for measuring harvester performance parameters. The measurement of harvester efficiency is simplified due to the complexity of power measurement and harvester efficiency is calculated from its parameters. However, this method is not accurate because it neglects mechanical losses and has a large measurement uncertainty. For this reason, the main objective of this work is to find a way to directly measure the harvester power input and thus measure its efficiency by definition, i.e. including mechanical losses. By analyzing the power flow in the harvester power chain, a way to achieve this goal has been found. Then, I have created an automated measurement system that allows to measure the harvester power parameters and also its efficiency including the determination of measurement uncertainties. In the last section, the performance, parameters and especially the two types of efficiency for commercially available harvesters are compared. As expected, the efficiency evaluated according to the definition come out smaller than in the case of its simplified version. However, this ratio varies widely for different harvester types, with the new efficiency being approximately one-third for PZT harvesters but only one-hundredth for PVDF harvesters. This significant difference shows that the different types of harvesters have large differences in mechanical losses, this difference could not be measured until now and thus remained neglected.
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Testbed for wireless power transfer system
Holas, Jiří ; Musil, Filip (referee) ; Chalupa, Jan (advisor)
The purpose of this work is design and making experimental device. It will be instrumental towards measurement effectivity wireless power transfer electric energy using help of inductive link. This work contains information about main factors, which influencing this transfer. Further I describe an operation design and each parts. These parts are mechanic or electric. In conclusion this work is functionality testing experimental device.
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Efficiency map of synchronous machine
Gargulák, Jiří ; Marada, Tomáš (referee) ; Pruša, Radomír (advisor)
Subject of this bachelor thesis is application of interpolation on efficiency maps of synchronous servo-engines. Nearest neighbor interpolation, inverse distance weighting and bilinear interpolation is used. Another part of this thesis is measuring on drive of one axis on machine tool, which is made out of frequency convertor, synchronous engine and a ball screw. Also another subject of this thesis is research of power losses in synchronous engine, frequency convertor and ball screw.
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Comparison of integrated circuits for management of single cell Li-ion battery
Novák, Štěpán ; Burian, František (referee) ; Kunz, Jan (advisor)
Lithium-ion batteries are now widely used as power sources for mobile devices, electric vehicles, consumer electronics and other applications. For proper operation and extended service life of Li-ion batteries, it is important that the parameters specified by the manufacturer are met. This is ensured by means of appropriate circuits, the accuracy of which is the focus of this paper. This work provides an overview and comparison of different types of circuits for Li-ion battery management and charging and explains the basic principles of their operation.
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Measuring the Parameters of Piezo Energy Harvesters
Kunz, Jan ; Novák,, Martin (referee) ; Hadaš, Zdeněk (referee) ; Beneš, Petr (advisor)
This dissertation deals with the measurement of piezoenergy harvester parameters, in particular the measurement of their efficiency. The first part of the thesis summarizes important metrics for their comparison and reviews existing measurement systems for measuring harvester performance parameters. The measurement of harvester efficiency is simplified due to the complexity of power measurement and harvester efficiency is calculated from its parameters. However, this method is not accurate because it neglects mechanical losses and has a large measurement uncertainty. For this reason, the main objective of this work is to find a way to directly measure the harvester power input and thus measure its efficiency by definition, i.e. including mechanical losses. By analyzing the power flow in the harvester power chain, a way to achieve this goal has been found. Then, I have created an automated measurement system that allows to measure the harvester power parameters and also its efficiency including the determination of measurement uncertainties. In the last section, the performance, parameters and especially the two types of efficiency for commercially available harvesters are compared. As expected, the efficiency evaluated according to the definition come out smaller than in the case of its simplified version. However, this ratio varies widely for different harvester types, with the new efficiency being approximately one-third for PZT harvesters but only one-hundredth for PVDF harvesters. This significant difference shows that the different types of harvesters have large differences in mechanical losses, this difference could not be measured until now and thus remained neglected.
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Efficiency map of synchronous machine
Gargulák, Jiří ; Marada, Tomáš (referee) ; Pruša, Radomír (advisor)
Subject of this bachelor thesis is application of interpolation on efficiency maps of synchronous servo-engines. Nearest neighbor interpolation, inverse distance weighting and bilinear interpolation is used. Another part of this thesis is measuring on drive of one axis on machine tool, which is made out of frequency convertor, synchronous engine and a ball screw. Also another subject of this thesis is research of power losses in synchronous engine, frequency convertor and ball screw.
|
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Testbed for wireless power transfer system
Holas, Jiří ; Musil, Filip (referee) ; Chalupa, Jan (advisor)
The purpose of this work is design and making experimental device. It will be instrumental towards measurement effectivity wireless power transfer electric energy using help of inductive link. This work contains information about main factors, which influencing this transfer. Further I describe an operation design and each parts. These parts are mechanic or electric. In conclusion this work is functionality testing experimental device.
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