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Design of high speed induction motor
Čech, Jiří ; Knebl, Ladislav (referee) ; Ondrůšek, Čestmír (advisor)
The first part of this paper presents general information about electromagnetic designing of an induction motor. Focus is on explanation of individual designing aspects and their effects on final motor parametres. Design principles for magnetic cores, slot dimensioning, stator winding and rotor squirrel cage are presented. Second chapter presents complete analytical computation of a given induction motor. Firstly several parametres need to be selected. Then sizing of stator and rotor is conducted. Secondly steady state equivalent parametres and related operating characteristics are computed. Following chapter consinsts of three final designs. In the last chapter results of mechanical analysis are presented.
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Operation of induction motor with respect to maximum efficiency
Čech, Jiří ; Ctibor, Jiří (referee) ; Toman, Marek (advisor)
In the first part of this paper a mathematical model of induction motor is described. With usage of -network equivalent circuit equations for calculation of individual power losses and overall efficiency are derived. Research study of loss minimization control is introduced in the next part. Several often used methods of variable frequency drive control are described. Also a review of loss minimization techniques from the perspective of induction motor control are presented. The last part of this paper includes a detailed description of scalar induction motor drive focused on reaching optimal efficiency. The loss minimization technique used is a model based method with rotor frequency being the control variable. At the end the performance of this method is verified using a computational script in Matlab.
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Financial Analysis
Braun, Karel ; Čech, Jiří (referee) ; Konečný, Miloš (advisor)
The bachelor thesis deals with a topic of corporation finance which comes under a financial management field. The work analyses a development and a level of financial position of company IMOS Brno, a.s. from 2001 to 2005. The aim of the work is to carry out financial analysis of real company and to make suggestions for improvement of company financial position. Results of the work will give information for a company management and its decision-making process.
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Special measurements in the field of 3D printing
ČECH, Jiří
The bachelor thesis focuses on the use of 3D printing in the field of measurement with a specific focus on translucency. Samples have been created to investigate which 3D printing parameters affect the translucency of the samples. The samples are printed under different nozzle temperatures, printing speeds, layer heights and other parameters. The task of the bachelor thesis was the design and optimization of the measuring equipment, using additive technologies to reduce the cost of production. The measuring device is based on an integrating sphere, which is a specialized device used for measuring various optical properties of materials. The main contribution of this work is the successful design and manufacture of a device that meets the specific requirements given by the properties of the samples for which it was intended. The measuring device does not display values exceeding 100 % transparency, unlike its prototype where values of transparency often exceeded 120 %. This inaccuracy was due to the lack of light scattering in front of the sensor, so a new device was made based on the spherical integrator. The device was tested on three samples, on which the prototype measurements yielded a translucency of over 100 %. The new measuring device no longer exhibits such errors. These particular samples show translucencies of 85, 74 and 85 % compared to the prototype measurement where these samples normally exceeded 120 %.
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Design of high speed induction motor
Čech, Jiří ; Knebl, Ladislav (referee) ; Ondrůšek, Čestmír (advisor)
The first part of this paper presents general information about electromagnetic designing of an induction motor. Focus is on explanation of individual designing aspects and their effects on final motor parametres. Design principles for magnetic cores, slot dimensioning, stator winding and rotor squirrel cage are presented. Second chapter presents complete analytical computation of a given induction motor. Firstly several parametres need to be selected. Then sizing of stator and rotor is conducted. Secondly steady state equivalent parametres and related operating characteristics are computed. Following chapter consinsts of three final designs. In the last chapter results of mechanical analysis are presented.
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Operation of induction motor with respect to maximum efficiency
Čech, Jiří ; Ctibor, Jiří (referee) ; Toman, Marek (advisor)
In the first part of this paper a mathematical model of induction motor is described. With usage of -network equivalent circuit equations for calculation of individual power losses and overall efficiency are derived. Research study of loss minimization control is introduced in the next part. Several often used methods of variable frequency drive control are described. Also a review of loss minimization techniques from the perspective of induction motor control are presented. The last part of this paper includes a detailed description of scalar induction motor drive focused on reaching optimal efficiency. The loss minimization technique used is a model based method with rotor frequency being the control variable. At the end the performance of this method is verified using a computational script in Matlab.
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Social interactions in cyberspace
Čech, Jiří ; Duffková, Jana (advisor) ; Lupač, Petr (referee)
This thesis deals with a relatively new, dynamically developing and unique environment that came into existence due to the global interconnection of computers into an international network - the Internet. Its ambition is to acquaint the readers with the circumstances of emergence and development of this phenomenon, which is the product of informational society as well as one of its creators. The thesis focuses primarily on the issue of cyberspace, the point of relative freedom and meeting of people from aH over the world entering with aH sorts of objectives. Its aim is also a general overview of the potential offered by cyberspace to its visitors and the ways it affects them. Special attention is paid to the fields of interpersonal communication and self-presentation within the frame of virtual reality. Last but not least, it offers an insight into the mutual agency or real world and cyberspace, taking place through its creators, users and divers social movements.
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Financial Analysis
Braun, Karel ; Čech, Jiří (referee) ; Konečný, Miloš (advisor)
The bachelor thesis deals with a topic of corporation finance which comes under a financial management field. The work analyses a development and a level of financial position of company IMOS Brno, a.s. from 2001 to 2005. The aim of the work is to carry out financial analysis of real company and to make suggestions for improvement of company financial position. Results of the work will give information for a company management and its decision-making process.
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