National Repository of Grey Literature 43 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Remanent magnetism of electromagnets of DC contactors
Horký, Jakub ; Píška, Jakub (referee) ; Šimek, David (advisor)
The master thesis is focused on a remanent magnetism of electromagnets of DC contactors. In the first part of the thesis deals with the formation of a magnetic field in different kinds of materials, description of their magnetization and sorting. The next part is focused on the principle and history of an electromagnet. Negative effects and remanent induction of the contactor are described in the end of the theoretical part. The second part is a practical part. First, the reaction times were measured on a pair of DC contactors. Using the obtained data, an electronic circuit was designed to minimize the difference in switching times of the given DC contactors.
Experimental Measurement Of Radial Temperature Distribution Of DC Arc
Šimek, David
The paper is focused on an electric arc spectroscopy diagnostics related to electric low voltage apparatuses. Measurement of radiation spectra of the electric arc burning between carbon electrodes with cooper admixture is presented. Cooper has a lot of suitable atomic spectra lines for calculation purposes. The problems connected with the measurements are discussed. The main part of the paper deals with a calculation of radial temperature distribution of the arc. Abel inversion was used to extracts the radial (2D) distribution from a one-dimensional projection measurement. Atomic lines database of National Institute of Standards and Technology was used as a spectral data source for the calculations.
Control of Low Voltage Contactor by calculation and measurement
Veselý, Matěj ; Šimek, David (referee) ; Bušov, Bohuslav (advisor)
The bachelor project deals with controlling mean parametres of low voltage contactor by calculation and measurement. Deals more specifically with calculation of the applied electrodynamic forces on the contactor's movable contact, the determination of the minimum compressive force on the contactor's movable contact and the design of the contactor trip system. It also deals with calculation of heating of the current-carrying path on contactor and its following check by measuring.
Design of DC electromagnet
Mayer, Aleš ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
This bachelor thesis deals with electromagnets and measurements on them. There is described the history of discovery of electromagnets, the principle of operation, their construction, and classification according to various criteria. More detailed descriptions of individual basic types are presented. The method of deriving the tensile force calculation is explained for DC as well as for AC electromagnets. There is a detailed description of the design process of a core DC electromagnet, which is then simulated in the FEMM program, and a 3D model with technical documentation is created in the Inventor program. The part also deals with measurement on electromagnets. More precisely, it is a measurement of static and dynamic tensile characteristics, measurement of electromagnets temperature rise. In the next part, transient phenomena and their measurements are explained, namely inrush current and switching overvoltage.
Assessment of the design of a small photovoltaic power plant for a family house and elaboration of its revision process
Kovaľ, Nikodém ; Šimek, David (referee) ; Veselka, František (advisor)
The bachelor's thesis deals with the assessment of a domestic photovoltaic power plant for a family house and the processing of its revision. At the beginning are explained the principle of conversion of solar energy into electrical energy, types of individual photovoltaic cells used in practice, methods of increasing the efficiency of photovoltaic modules, the most common failures of PV modules and methods of their detection. Furthermore, the assessed photovoltaic power plant is presented, its theoretically described components, graphical dependencies showing its production and the possibilities of increasing its production. The practical part of the work deals with the revision of the assessed PV plant and its documentation.
Temporally and spatially resolved diagnostics of an electric arc
Holcner, Oldřich ; Šimek, David (referee) ; Kloc, Petr (advisor)
This batchelor thesis "Temporally and spatially resolved diagnostics of an electric arc" deals with the investigation of plasma temperature in an arc formed by evaporation of copper wire. It is an optical method based on determination of temperature from intensity of spectral lines. In this batchelor thesis we explain how spectral lines are formed and how to determine the temperature. In the practical part we process discharge and show the time evolution of temperature at the measured points.
Software for evaluation of data from CVVOZE laboratory
Petráček, Dominik ; Šimek, David (referee) ; Pikula, Stanislav (advisor)
The diploma thesis is focused on the innovation of partially user-unsuitable software which is used in the CVVOZE short-circuit laboratory for the evaluation of testing of switching and protection devices. The introductory part of the work presents a technical laboratory, which is used for research and development in the field of electrical devices with possibility of testing of short circuits and over-currents. At the first part of thesis, there is made a description of the technical laboratory. The following past is a chapter with basic introduction of tested devices and standard testing conditions of electrical devices in the laboratory. Then following a description of the original evaluation software is made and its shortcomings are pointed out. The practical part is devoted to the creating in LabVIEW, implementation and verification of the functionality of the new evaluation software.
Analysis of electrodynamic forces in electrcal apparatus
Dobrovolný, Jan ; Valenta, Jiří (referee) ; Šimek, David (advisor)
The master thesis deals with the phenomena called electro-dynamic force in the electrical apparatus. Nowadays, there are high requirements for electrical devices. The devices and especially their contacts are subject to high demands on reliability, reliability and mechanical durability. The electro-dynamic forces caused by the passage of electric current mechanically deform the current path. The design of the electrical apparatus must take these forces into account. Equations for electro-dynamic forces calculation are presented. In master thesis, individual parts of the current path are derived and described. Various configurations and designs of the current path are solved. The thesis also deals with the issue of forces in electrical contacts. Individual theoretical equations are then applied to a particular disconnector QAK, made by company IVEP, a.s. Parts of the disconnector were redrawn into 3D program SolidWorks. The model was analysed in program ANSYS Maxwell. The thesis compares the achieved results of analytical equations and numerical simulations.
Diagnostics of medium voltage and high voltage circuit breakers
Kapalla, Alexej ; Šimek, David (referee) ; Dostál, Lukáš (advisor)
This bachelor work is focused on medium-voltage and high-voltage circuit breakers and their diagnostics. The thesis presents the history of HV circuit breakers and their main division. Subsequently, the relevant standards are listed in the work and diagnostics of the MV circuit breaker VD4 and the HV circuit breaker S1-245 from AEG is performed. In case of the VD4 circuit breaker, a new and used circuit breaker was diagnosed. The measured values are then compared and the impact of usage is shown. The work describes the measurement of main contact resistance, insulation resistance, closing and opening times and vacuum quality.
Investigation of the durability of low voltage switching apparatuses construction parts
Dalecký, Jan ; Dostál, Lukáš (referee) ; Šimek, David (advisor)
This thesis deals with study of durability of low voltage switching devices components. It describes components of circuit breaker and low voltage contactor and contains function models of these devices in various states. Based on model analysis, components that can get worn, damaged or destroyed were selected. Further practical experiments on two samples of circuit breakers from different manufacturers were executed to verify their technical parameters and parts durability. Failure of some components can cause switching device to malfunction.

National Repository of Grey Literature : 43 records found   previous11 - 20nextend  jump to record:
See also: similar author names
17 Simek, David
1 Šimek, D.
6 Šimek, Daniel
3 Šimek, Dominik
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