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Thermal analysis of induction machine using thermal network method.
Jiroušek, Petr ; Klíma, Petr (referee) ; Světlík, Martin (advisor)
This paper deals with the thermal analysis of an induction motor. In the first part the principle of its function and possible design are discussed. The second part discusses the mechanisms of heat transfer methods, which are conduction, convection and radiation. Next chapter is devoted to the description of the thermal network method and contains the designed network for a specific induction motor. The fourth chapter includes the thermal resistance equations and their description together with a simplification of the machine geometry. The fifth key chapter defines the input parameters of the calculation and mainly the calculated temperatures of the nodes of the thermal network.
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Analysis of Current Higher Harmonics Impact on Losses in Transformer Foil Winding
Žďárský, Jan ; Klíma, Petr (referee) ; Mrajca, Miroslav (advisor)
This paper deals with the analysis of the effects of non-sinusoidal current on the foil windings of power transformers. This issue is important in transformer design since losses are measured only when sinusoidal current is passed through. In some applications, these losses need to be recalculated to account for the effect of higher harmonics of the current in actual operation, as these losses are related to transformer heating. A literature search of available sources that have already described this issue is performed in this work. In this paper, a model for simulation in Ansys Maxwell environment is presented, using which the losses due to higher harmonics will be calculated.
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CO2 capture in a spray column using different atomization techniques
Klíma, Petr ; Bělka, Miloslav (referee) ; Malý, Milan (advisor)
Carbon dioxide capture (CO2) can be a key step in the fight against global climate change. One of the promising tehcnologies for CO2 capture is the spray column. This diploma thesis investigated its potential through a review of available literature and laboratory experiments. Specifically, the work included an overview of absorbents and nozzles. Furthermore, research was conducted on the geometric and operational parameters of spray columns and other similar devices used for CO2 absorption and desorption. These findings led to the construction of a spray column and the execution of experiments. The effect of the type of nozzle used, as well as the effect of CO2 concentration in the supplied gas, the effect of atomization pressure and the effect of temperature on the absorption efficiency in the spray column were investigated. Regeneration experiments were also carried out in a spray column and then on a smaller scale in a steel cylindrical vessel.
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Efficiency improvement possibilities of single-phase line-start synchronous machines
Mareček, Šimon ; Klíma, Petr (referee) ; Lolová, Iveta (advisor)
With increase in consumption of electric energy there is also increase of cost related to operation of single-phase induction motors (SPIM), which are mostly used in household applications. This is the reason of focusing thesis to single-phase line-start permanent magnet synchronous machines (SPLSPMSM), which has higher initial costs but also higher efficiency so they have potential to replace single-phase induction motors. That is the reason why the first chapter presents a literary research focusing on the topic of induction machines. The next chapter is dedicated to literary research of used SPLSPMSM and deals not only with their construction but also with transient phenomenon and steady state. Readers will learn about most common used laying of permanent magnets in SPLSPMSM in the next section. Then there continues chapter with possibilities of synchronization increasing because it is an important phenomenon connected with this type of rotating machines. Mathematical model is present in the next section of thesis. There are written equations, which lead to creating an analytical model. An equally important part presents an electromagnetic model and his description, which follows right after mathematical model. There are summarized the most important parameters and their influence on the efficiency of SPLSPMSM in the last but one chapter. In the last chapter there is a comparison between the mathematical and electromagnetic model.
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Optimization of high-speed induction machine
Cajzl, Jakub ; Světlík, Martin (referee) ; Klíma, Petr (advisor)
This thesis deals with the multi-objective optimization of a high-speed asynchronous machine. The introduction is devoted to materials and losses in high speed asynchronous machines and comparison of basic rotor topologies. The next part of this thesis summarizes the basic information related to the optimization principles and the basic classification of optimization algorithms. Then the specific algorithms used in optimization problems are described in more detail. The main part of this thesis deals with proposals for increasing the efficiency of the original 2,5 kW high-speed asynchronous machine, which are verified by electromagnetic calculations. Furthermore, the optimization itself is already performed using the NSGA-II genetic algorithm created in Python. The optimization results are evaluated and the selected optimized models are compared with the initial and modified machine models. The efficiency of the 2,5 kW machine has been successfully increased mainly due to the radially slitted rotor with copper end-rings and the use of stator plates with lower core losses. By optimizing the machine geometry, the power factor was increased and winding and friction losses were reduced.
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Closing mechanism paper bag
Klíma, Pavel ; Anderle, Martin (referee) ; Dvořáček, Jiří (advisor)
This thesis deals with a design of new dot-wheels gearing. These wheels serve for closing of paper covers of tea bags. First of all the suggested spare options of the gearing shape are compared with the original. On the basis of the comparison results the gearing is solved as a substandard kind of involute gearing. The involute gearing is designed by the method of generalized parameters. For the gearing design the program GEARING – symetrical profile version 1.5. was used. Consequently this program was adapted for the case of the change of the instrument shape by the user. The kind of wheels material was designed. Further the way of wheels production for single-piece and batch production was also designed. At the end the economic evaluation of the wheels production with newly designed profile was done.
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Creation of GUI for optimization of electrical machines
Bártková, Tereza ; Klíma, Petr (referee) ; Knebl, Ladislav (advisor)
This work follows the development process of graphical user interface (GUI) spanning from choosing the right tools for implementation to the implementation itself. The purpose of the work was making the optimization program user-friendly by creating a communication layer between the optimization algorithm and the user and demonstrating its functions. First of all, the study of various programming languages and their toolkits regarding GUI programming was undertaken. Python was chosen because the original program is written in it, also software development in Python is probably the quickest one. Furthermore there are analyzed characteristics of this language and PyQt, which is a tool meant for GUI creation. The third chapter introduces very thoroughly the issues of electrical machines and their optimization. Introduction of these issues is followed by brief description of two optimization methods being used in electrical machines optimization. Following chapter introduces the actual machine under the optimization study, on which the final program was tested. Afterwards follows detailed description of application layout created in Qt Designer. New program structure enriched with graphical user interface is described and its functions are shown. Finally there is a guideline on how to use this program and the optimization is executed accordingly. Also, the results of the optimization are analyzed.
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Thermal analysis of servomotor
Přibyl, Daniel ; Duroň, Jiří (referee) ; Klíma, Petr (advisor)
This thesis deals with the design of the thermal model of servomotor in program Motor-CAD and using it for analyze of servomotor. In the beginning is a short familiarization about its parts, especially important for the thermal model. Further are described principles of heat exchange. There is a chapter, which is dedicated to the program support of the Motor-CAD. Thermal model and electromagnetic model inputs are tuned according to the measured data. Then a way of active cooling is designed and based of it the model in program is edited. Using the model is found the points of load of the motor for maximum allowable temperature with water cooling. In the conclusion is a valorization of benefit of water cooling for the servomotor.
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High-speed Condesing Steam Turbine
Klíma, Petr ; Trojan, Aleš (referee) ; Fiedler, Jan (advisor)
ith one controlled extraction and one uncontrolled extraction, calculation of the flow channel at all stage, design and calculation of the regulation valve and create connection diagram of steam turbine and air cooled condenser. At the beginning of this work is an overview of manufacturers of steam turbines and their unified products. Master thesis was developer with G-Team, a.s. as using calculations and the instructions given in the recommended literature with supporting CFD simulations to determine the loss coefficients and FEA simulations to determine the eigenfrequencies blades.
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