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Switching loss reduction in the switch-mode supplies
Vašíček, Adam ; Vorel, Pavel (referee) ; Patočka, Miroslav (advisor)
The master's thesis covers in its first parts origins and consequnces of the switching losses, basic principles of the various resonant tanks and resonant DC/DC converters. Afterwards the innovative approach of the multiperiod modulation is presented. The main advantages of this kind of modulation include very wide zero current switching region and lowering the switching frequency as the output voltage decreases. In the remaining part of the thesis a prototype converter design is described.
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Calculation of optimum slip frequency of induction motor for minimisation of its losses
Bednařík, Václav ; Patočka, Miroslav (referee) ; Vorel, Pavel (advisor)
This master’s thesis focuses on the minimisation of losses by calculation of optimum slip frequency of induction motor. The next point of this master‘s thesis is supersaturation. Supersaturation must be solved for the size of losses, because of the effect that is cause of the losses, when current increases with saturation. However current is not increase proportionally with increasing saturation, but increases several times more. This problem is included in the calculation of the slip frequency. Optimum of slip frequency is solve for modified gamma model of induction machine. In the main point of this thesis is outlined the process, how the optimum can be found. With same process were already were found the equations, but they were too extensit. In the end is solved the optimum of slip frequency be minimum of the flux density.
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Family house in passive standard
Svoboda, David ; Jelínek, Petr (referee) ; Sedlák, Jiří (advisor)
The bachelor's thesis on a topic “The family house of standard passive” deals with the design of the house for family housing in accordance with applicable legislation. The house is designed in the Highlands on the edge of developing area Račerovice. The cellarless two-storey building is made of brick. The roof is according to local regulative plan made up of saddle-shaped truss system. The passive character of the house requires large glass areas on the south facade of the house and high-quality thermal insulation of the building envelope with minimal losses. The house is associated with a brick garage with a shed-roof.
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Efficiency Improvement of Small Induction Motors
Vilím, Martin ; Veselka, František (referee) ; Hájek, Vítězslav (advisor)
In this bachelor´s thesis I discuss about asynchronous engines in general, describe their construction and principle of operation, using. It also includes measurements of a specific motor and design engine. The first part deals with theprinciple of the engine options including the fundamental control over speed and torque. The second part deals with the measurement of the size of the searchengine and losses. The last part provides a proposal for a new induction motor.
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Automotive Alternator Innovation
Volek, Martin ; Hýsek, Roman (referee) ; Hájek, Vítězslav (advisor)
The work deals with the analytical electromagnetic design of automotive claw-pole alternator 14V/120A. This design is verified in program Maxwell with a RMxprt tool. The results of both calculations are compared. Designed alternator is also compared with the results measured in the laboratory on the alternators of similar type. Furthermore, there are analyzed individual power losses of machine and listed options of reducing these losses, which results in an increase in overall efficiency.
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Design of synchronous linear motor thermal network
Čech, Jan ; Toman, Marek (referee) ; Knebl, Ladislav (advisor)
The first part of this thesis deals with the study of linear motors. The introduction of the thesis deals with the brief description of the linear motor, including its accessories. This part explains principle of linear motors, their general advantages and disadvantages. The next section contains an overview and division of the currently used linear motors. The second part deals with the theoretical description of forms of heat transfer. The third part of the thesis deals with the design of an equivalent thermal circuit model of a linear iron-core linear motor with permanent magnet. Hereafter, the proposed design will be used to calculate the temperatures of the individual motor units. The temperatures are later compared with the results obtained with finite element method.
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The Material Flow Production System Analysis and Improvement Proposals
Marešová, Petra ; Kuruc, Miroslav (referee) ; Bartošek, Vladimír (advisor)
This thesis focuses on the analysis material flow of the production system at ABB Ltd. and suggestions for improvements. The work consists of theoretical, analytical and design parts. The theoretical part contains the basic concepts of production. In the analytical part, there is described a current situation in production areas of the company on the basis of theoretical knowledge. In the final part, the solutions are designed to help improve the business.
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Automobile Charging System
Kovačík, Lukáš ; Janda, Marcel (referee) ; Hájek, Vítězslav (advisor)
This Bachelor thesis analyzes recharging systems in automobile. It explains main components of electric circuit used in automobile alternators, functions of each part of the alternator, comparison of the most common types of alternators. Main focus is to analyze and inovate the area of power losses, which determines the efficiency of each type. Final part of this thesis describes the analytical calculation of a three-phase generator.
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