National Repository of Grey Literature 89 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Modern motor vehicle batteries
Komárek, Radim ; Šebela, Kamil (referee) ; Štětina, Josef (advisor)
In response to pressure from the European Union to reduce emissions, requirements on car manufacturers are increasing, paving the way for a shift from traditional internal combustion engines to electric drives with energy stored in batteries. The battery itself is made up of modules in which battery cells are stored. To get the correct voltage output, the battery modules and the cells in them need to be wired. Where parallel wiring of the cells with serial wiring of the modules is most appropriate. The most commonly used cells are cylindrical and prismatic cells, which are further divided into prismatic cells and pouch cells. Cylindrical designs are suitable for applications where maximum power output is required, while prismatic designs are better in energy efficiency. Thermal management is very important to keep the batteries within a narrow temperature window. Liquid cooling is preferably used, which has an order of magnitude higher efficiency. This thesis focuses on the analysis of these technologies and their impact on the efficiency and lifetime of battery systems in the automotive industry.
High-current solid state relay
Daďa, Pavel ; Ctibor, Jiří (referee) ; Červinka, Dalibor (advisor)
The bachelor's thesis deals with the design of an electronic semiconductor contactor for power switching of battery systems. The work includes familiarization with the function and use of photovoltaic systems and familiarization with types of battery systems. Furthermore, the original solution using the GIGAVAC GX23 power contactor and introduction along with the design and dimensioning of the newly proposed solution using a power semiconductor contactor. The conclusion of the work summarises the findings of the design and possible extension of the final product. The text of the thesis is divided into six chapters. The first chapter contains a description of the issue of connecting battery modules in the FVE area. The second chapter deals with the issue of connecting battery blocks. The third chapter contains a general description of the SSR for alternating voltage switching. The following fourth chapter describes SSR relays for dc voltage switching. The fifth chapter describes the specific solution of the power switch including the dimensioning of the power elements and the design of the radiator. In the next chapter, the knowledge and possibility of further development of the SSR contactor.
Automation of the calibration process
Mařas, Michael ; Šedivá, Soňa (referee) ; Beneš, Petr (advisor)
This master thesis deals with the automation of the calibration process at the workplace for calibration of electronic power meters and the description of the method of evaluation of calibration results. The paper analyses the calibration workstation and the manual method of calibration performed by the calibration laboratory staff. Furthermore, proposals for automating the manual method of calibration and a description of the implementation of a program for automating this process are given. Subsequently, the uncertainty analysis is described in the paper. In this section, the uncertainty analysis according to the GUM method and the subsequent calculation of these uncertainties are presented. The correctness of the calculation of uncertainties according to the GUM method is verified by the Monte Carlo method. In the last part of the work, the method of evaluation of the calibration results according to ILAC-G8:09/2019 is described and the form of the calibration protocol is described.
Non-standard methods of current and voltage measurements
Talába, Michal ; Boušek, Jaroslav (referee) ; Hubálek, Jaromír (advisor)
This work brings a study about non-conventional methods of voltage and current measurement, followed by a creation of magneto-resistive material based current sensor prototype, suitable for medium voltage switchgear from ABB. Outcome of the study is description of physical principle and the measurement principle of non-conventional methods. Outcome of the experimental part is a current sensor based on magneto-resistive component, which can measure magnetic field generated around a wire with flowing primary current. Through the magnetic field, the sensor can measure primary current flowing in the wire. Sensor was measured in range 0 – 1000 A, and its accuracy and linearity was approximately 6%. The main contribution of this work is the confirmation that this non-conventional method works for measurement of high currents. Based on the outcome, ABB can decide whether is this technology suitable for its product portfolio.
Bus wiring systems for complex building management
Mokrý, Lukáš ; Macháček, Jan (referee) ; Bátora, Branislav (advisor)
The aim of my thesis is to examine current opportunities of bus wiring systems for complex building management, mainly its power and economic evaluation. It can be simply called intelligent electrical installation. I will examine two systems from INELS and ABB company. These systems contain functional components, mainly modules and controllers. By means of other materials, I’ll create a panel. Components will be placed there and electrically connected. After this, systems will be put into operation and programmed by means of their software. The next step is measuring of quatities during the various conditions of systems and consumption, which is one of the main aims of the thesis. Two apparatuses will be used for measuring. This thesis itself will contain theoretical analysis of systems, their description, using the way of operation and main advantages and disadvantages. Single components and complete process of measuring and working in laboratory will be described. An overall evaluation and comparison of the systems from various points of view, including the price, will be put together from results.
Design of Experiment
Lachnit, Zdeněk ; Bednář, Josef (referee) ; Kotek, Luboš (advisor)
The main subject of this master thesis is to evaluate using of Design of Experiment in industrial company in the development of LED modules for cars. In background study Design of Experiment methodology is described. Next part of background study describes the general principles of termography measurements, next chapter includes the information’s about LED technology and temperature degradation. At the beginning of the practical part is a description of the team analysis due to selection of factors, next chapter validates importance of vias. In next chapter methodology of print circuit board preparations and measuring are described. A next chapter describes the implementation of design of experiment at voltages 8 V, 13,5 V, 16,5 V. Designs of Experiments were made for four or five factors. The reason for this decision was the manual adjustment of printed circuit boards. At the end of each Design of Experiment is the recommendation of factors and interactions settings with regard on response, which is the minimal temperature. At the end of master’s thesis is the final evaluation.
Proposal of topology of piezoceramic composite sensor
Dostal, Vojtěch ; Ševeček, Oldřich (referee) ; Majer, Zdeněk (advisor)
This master thesis deals with design and numerical modelling of piezoceramic sensor, which is placed on a rail, in order to generate electrical energy, which can be used for wireless monitoring of railway traffic and to monitor the condition of the railway. The thesis is divided into three parts. Theoretically background of piezoelectric energy harvesting is described in first part, where some previous application of piezoelectric generator in railway area are shown. In the second part, parametric analysis of numerical model is performed, which directly leads to finding best location on a rail, where piezoelectric generator should be placed. For this analysis the homogenized model of MFC sensor was used. Results of the numerical model were then compared with the results of the conducted experiment. The third part presented own design of piezoceramic sensor, which is placed onto most suitable location on a rail. Results from numerical analysis shown eligibility of using piezoceramic sensor to monitor the railway traffic.
Comparison of measured and simulated characteristics of temperature sensors
Vitek, Juraj ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The aim of this work is to study all kinds of electrical temperature sensors, their categories, use and accuracy. I also made a functional simulator for metal electrical sensors with measurement.
Stabilized operation of the 400 kV power line
Jurča, Ondřej ; Bok, Jaromír (referee) ; Blažek, Vladimír (advisor)
This thesis deals with methods of solving lines under voltage levels of a very high transmission voltage and extra high voltage. The first, theoretical part of this paper analyses different methods how such lines are solved. In particular, an accurate solution is provided simulated by means of a line with evenly distributed parameters, and an approximate solution simulated by means of a line with lumped parameters. Furthermore, special cases of steady running conditions of the line are reviewed, such as no-load running, short-circuit run and line operation with natural load. In conclusion of the theoretical part is given a general method of solving an extra-high-tension and extra high voltage network; also, some graphical methods of solving such networks are shown including their brief description. The second, practical part of the present paper involves application of the above mentioned methods of solution on a specific line with given parameters, solving conditions at the beginning of the line under steady running conditions and in special cases of the line operation. The conclusion of the thesis summarises the obtained results and provides final assessment of the individual methods of solution in terms of calculation accuracy.
Optimalization of Induction Furnace Operation in foundry Vsetín
Trachta, Jiří ; Nowak, Stanislav (referee) ; Lázničková, Ilona (advisor)
The aim of this work is optimalisation of induction furnace in foundry for company PROMET FOUNDRY a.s. The company has two induction furnances. There are installed as identical construction. They have 2 modes of operation. First mode is founding and second mode is mode, where is temperature in maintain mode. Only one induction furnance can work in the founding mode at a time though. Inducion furnances are in the single-phase connection and they cause unbalance in the distribution network. Near the foundry there is a small network area whitch it is operated by company Zásobování teplem Vsetín a.s. The consumption of electrical energy in foundry so big, that in the year 2009 was made elaborate for Zásobování teplem Vsetín a.s. It was write at Laboratoře diagnostiky výkonů (Laboratory of performance diagnostics), which is a part of Electrotechnic Department at Technical Univarsity of Ostrava. The ordered study was named “Verification of causes of increased reactive energy consumption during transition from electricity delivery to electricity consumption”. The conclusion of this assignment confirms that in distribution network in the Jiráskova area in Vsetín there is unbalance of electrical energy and there is high part of reactive power. The next conclusion is crucial to find the customer who made the unbalance and to set relevant remedy. The last step will be the identification whether such device can actually be effectively balanced. It was subsequently proved that the Promet Foundry was causing the unbalance and that balanced consumption would be reasonable. Promet Foundry thus addressed Autel a.s. company with an inquiry to make a study of removing the causes of the unbalance which is caused by current induction furnaces operation at a minimum possible cost, least possible influence on the performance and minimum construction changes concerning the building. In this thesis there will be some topics. The result of which will be introducing of used heating technology, introducing of company and of effective plant performance and subsequent suggestions of possible unbalance removal or reactive power decrease. Several ways which are being implemented in the industry in order to balance consumption will be described. A suitable balancing plant will be subsequently chosen and its parameters will be calculated.

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