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Induction motor modification for synchronous operation
Pochyla, Martin ; Ondrůšek, Čestmír (referee) ; Vítek, Ondřej (advisor)
This paper is focused on customization of induction machine type STM71-4L. The need of optimal mechanical design is presented, to achieve sufficient synchronizing reluctant torque, which will result in rotor synchronization with stator magnetic field. Final mechanical design is suggested after research, which considers influence of the essential rotor dimensions on resulting electromechanical torque. This is provided with usage of finite element method calculation. As a result of the thesis the combination of two basic machines – induction machine and synchronous motor is presented. The measurement on induction motor, and it´s modified versions is presented in following chapters. In the last chapter the results of optimization and measurement are discussed and compared.
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Measurement of automotive alternators using LabVIEW
Kufa, Daniel ; Aboelhassan, Mustafa Osman Elrayah (referee) ; Vítek, Ondřej (advisor)
This work presents development system LabVIEW and the possibility to create virtual measuring devices. Particular realization of virtual measuring device within the frame of this work is applied on measurement of basic characteristics of claw-pole alternator. The structure and the principle of function of this alternator is described in brief. Created virtual measurement device is described in detail. The entire block scheme, that is the source code for LaBVIEW development system, is attached only in electronic form. The printed version contains front panel of the device and almost all the structures of block scheme.
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Program for calculation of BLDC motor
Chloupek, Karel ; Janda, Marcel (referee) ; Vítek, Ondřej (advisor)
This thesis focuses on problematics of BLDC motors. Thesis consist of theoretical and practical part. In introduction is the reader acquaint with problematics, principals of development, advantages and disadvantades of BLDC motors. Then folows a description of different types, their realization and construction. Main part of this thesis deals with segment stator. For this type of magnetic circuit was developed computing software. This software will design and provide calculation of motor due to given parameters. In second step, the program generates source code for FEMM software, which provides a simulation. This is the most effective way, how can designer simply verify his calculations
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Increase the Rated Voltage of the Vehicle's Circuit - Study
Horák, Richard ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
The point of this work is evaluate the parameters of automotive electric system and according to these properties choose suitable norm of higher voltage, propose conception of system and with analyst calculation suggest basic granary parameters of higher voltage. This calculation is enclosed. In the work is mentioned a historical development of required escalation in system and therewith connected changes of specified levels of system tension. As an exemplification of escalation calculus hereof electrical equipment, installed onto motor powered vehicle, are mentioned in attachment schema's of four vehicles Škoda Auto a.s.
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Single-Phase Induction Motor Calculation
Schlesinger, Petr ; Vítek, Ondřej (referee) ; Hájek, Vítězslav (advisor)
This master’s thesis’s target is to introduce the basic findings about single-phase asynchronous motors, their derivation from three-phase motors and the basics of a computation process and a concept of a single-phase asynchronous squirrel cage motor. The inbeing of this concept and the computation is created by classical processes for three-phase motors with a low voltage, 50 Hz.
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DC machine measurement and analysis using LabView
Loun, Lukáš ; Hájek, Vítězslav (referee) ; Vítek, Ondřej (advisor)
The virtual laboratory is divided into two groups. The first group is comprised of a virtual laboratory for simulation. It is mostly used for presentation and demonstration purposes. It is not necessary to install complicated and expensive software for their use. The second group of the virtual laboratory is a long distance measure. Real systems are measured with the help of this laboratory. The advantage of long distance measuring is that data from the measurements are saved directly onto the personal computer and they can be immediately evaluated. In this project the procedure for creating a virtual instrument for long distance measuring is described in the LabVIEW program. LabVIEW is a graphic developmental environment, for the measuring and analysis of data.
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Electronically commutated motor
Vykopal, Petr ; Melichar, Petr (referee) ; Vítek, Ondřej (advisor)
The main idea that lead to the development of EC (electronic commutation) motors is to remove from commutation motors, called DC (direct current) motors, the mechanical commutation system i.e. the cylinder brushes and the commutator that limits in most of the applications the longevity of direct current motors. The commutator is the source of electromagnetic interference and it limits the motor speed. At the same time it is required to keep the outstanding features of DC motors, mainly the multiple overload capacity, high starting torque, low time constant and small dimensions. Thesis introduces the problematic of electrically switched machines and their possible construction versions. Based on obtained findings there is performed an analytical calculation of EC-machine with classical stator (made with two grooves on pole and phase) and with segmental stator for given parameters. With the known parameters of the machines from personal design there were created models of both machine types, and the results obtained from the program FEMM were compared to those of analytical calculations.
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Physical Fields Modelling of EC Motor's
Kružík, Pavel ; Vítek, Ondřej (referee) ; Janda, Marcel (advisor)
This thesis concludes a description of construction and functions of Electronically commutated motors. The main target is modelling of thermal field of Electronically commutated motors. For modelling was chosen Ansys Workbench setting with CAD geometry. There was a measurement for verifying result of simulation, and its proof is described in my thesis. This project also concludes comparison of results from simulation itself and results obtained from measuring thermal profile of EC motor.
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Agricultural insurance
Vítek, Ondřej ; Ducháčková, Eva (advisor) ; Daňhel, Jaroslav (referee)
This thesis deals with risks threatening agricultural activity, with agricultural insurance and with state aid to agricultural insurance in the Czech Republic. Furthermore, it describes history and development of agricultural insurance in the Czech Republic. Under this chapter is explored dependence of the premium on selected factors. The attention is also paid to agricultural insurance schemes in 16 selected countries of the world. Consequently, there are proposed possible suggestions of improvement of current agricultural insurance system in the Czech Republic with regard to foreign practice. The supply of crop insurance including a practical example of farmer using crop insurance in his risk management is concisely described in the end of the thesis.
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Analysis of agricultural insurance in the Czech Republic
Vítek, Ondřej ; Daňhel, Jaroslav (advisor)
This bachelor thesis deals with the agricultural insurance in the Czech Republic. The first part of this thesis is devoted to the description of agricultural insurance, the risks to agricultural activity including possibilities for their reduction or elimination. Furthermore, it describes the state support for agricultural insurance. The second part of this thesis analyzes the development of agricultural insurace in the Czech Republic. The agricultural insurance products of individual insurers are described in the final part of this thesis.
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