National Repository of Grey Literature 30 records found  beginprevious21 - 30  jump to record: Search took 0.01 seconds. 
An Analysis and recommendation for innovation concernig an oil tap changer
Zoufalý, Marek ; Veselka, František (referee) ; Bušov, Bohuslav (advisor)
In this bachelor thesis is described the theory of regulation voltage transformers, power transformers, types of regulation in general. Then there is described the state of tap changers. There are mentioned some of the leading manufacturers of tap changers. Also analysed is the revision of tap changer MR MI501 and replacement of oil tap changer Škoda OPZ for new SMS Huaming CV, made by REVOS company.
Reducing transformer inrush
Zoufalý, Marek ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
In this thesis is described the function and design of the transformer designed on ferromagnetic core, composed of transformer sheets. It is explained a transient inrush current of the transformer. In this work is inserted voltage and current waveforms, designed printed circuit board, serving to reduce the inrush current.
Design of Vibration Energy Harvester with Using of Non-linear Characteristics
Rubeš, Ondřej ; Ondrůšek, Čestmír (referee) ; Hadaš, Zdeněk (advisor)
This thesis is focused on design of piezoelectric energy harvester with additional nonlinear stiffness. Linear generator has very narrow resonance frequency bandwidth. It makes the resonance mechanism very sensitive to tuning up of the resonance frequency and it can be tuned only for one narrow vibration peak. The main idea for using of the vibration energy harvester with nonlinear stiffness is to make resonance frequency bandwidth wider, so the generator will be useable for more excitation frequencies. In this thesis is used generator Midé V21BL and additional nonlinear stiffness is realized with permanent magnets.
Design and analysis of electromagnet
Macek, Pavel ; Skalka, Miroslav (referee) ; Vítek, Ondřej (advisor)
This work deals with a proposal and an analysis of electromagnets. The first chapter is an introduction into solve of the problem. In the second chapter there is a general discussion about basic relations of the electromagnetic field. The third chapter is dedicated to the operation principle and construction of electromagnets and is supplemented with their common classification. The fourth chapter introduces the Finite Element Method and the FEMM programm. The fifth chapter is dedicated to the analysis of the DC electromagnet, the sixth chapter analysis single-phase AC electromagnet. In the seventh chapter there is a review of results of general analysis of both electromagnets.
Diagnosis of electromagnetic origin vibrations in asynchronous motor
Koníček, Pavel ; Dostál, Lukáš (referee) ; Janda, Marcel (advisor)
The aim of this master´s thesis is to introduce methods of diagnostics of vibrations in electrical machines. Describe the various vibration sources located inside and outside of the electric machine. Description of the sources of vibration is then preferably dedicated to vibration of electromagnetic origin. There is a description of the construction of an asynchronous motor and the magnetic circuit, the theory of vibrations and their origin. Described are also vibration sensor enables measurement and mathematical tools for their evaluation. In this work also practical vibration measurements on an asynchronous motor, data processing, their subsequent analysis and computer simulation of electromagnetic vibration origin. The conclusion of this work is devoted to the evaluation of the data obtained.
Reducing transformer inrush
Zoufalý, Marek ; Bušov, Bohuslav (referee) ; Dohnal, Petr (advisor)
In this thesis is described the function and design of the transformer designed on ferromagnetic core, composed of transformer sheets. It is explained a transient inrush current of the transformer. In this work is inserted voltage and current waveforms, designed printed circuit board, serving to reduce the inrush current.
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
Bushing-type current transformer 25 kV, 400/5/5 A
Bálint, Zoltán ; Vávra, Zdeněk (referee) ; Vaněk, Jaromír (advisor)
The aim of this master’s thesis is the design of a double-core bushing-type current transformer. This appliance is intended for measuring and protection of high-voltage distribution systems of the internal type for the highest system voltage of 25 kV. The master’s thesis is divided into four parts. The first part describes the function of the current transformer. The next part deals with the analysis of the phasor diagram and errors of the current transformer. The major part of the thesis deals with the design of the protective and measuring core. The last part describes the 3D model of the bushing-type current transformer.
Test of remanency in a sport damper in dependence on a material of magnetic circuit
Polášek, Jan ; Kubík, Michal (referee) ; Roupec, Jakub (advisor)
This bachelor’s thesis deals with testing of maximal magnetic induction, remanence and B-H curve of different kinds of steels and application of this knowledge when choosing materials for magnetic circuit of magnetorheological (MR) dampers. The introduction of the thesis is intended to analyse knowledge of magnetorheological fluids and magnetic characteristics of different kinds of materials. Another part of bachelor’s thesis deals with the choice of steels of different chemical composition, heat treatment of steel, testing and comparing with FEM results. The aim of the thesis is also to design a clamping device for testing of magnetic circuit and to describe used measuring instruments and measurement methodology too.
Vibration Harvester for Aircraft Applications
Rubeš, Ondřej ; Vetiška, Vojtěch (referee) ; Hadaš, Zdeněk (advisor)
This thesis is focused on modification of a design proposal of a vibration energy harvester for autonomous aircraft applications. Vibration energy harvester is mechanism, which converts vibration energy to electric energy. Its main parts are oscillating mass, magnets and coil for electromagnetics induction. The thesis is consisted of simulations of magnetics circuits, creating 3D model of harvester and simulations of oscillations with parameters from 3D model, magnetics simulations and with input sample of exciting vibrations.

National Repository of Grey Literature : 30 records found   beginprevious21 - 30  jump to record:
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