|
|
Warming of the disconnector, type KBE, 38 kV, 4000 A
Švábek, Ondřej ; Šimek, David (referee) ; Bušov, Bohuslav (advisor)
The bachelor's thesis is focused on the theory and calculation of the thermal effects of electric current and temperature-rise test of the disconnector KBE 38 kV, 4000 A. Another important part of this thesis is familiarisation with the electrical devices of the company IVEP, a.s. and studying norms related to disconnectors. The procedure for the calculation of warming of a particular disconnector is described within the thesis. The last part of the thesis evaluates the results of calculation and measurement.
|
|
|
Process model of the switchgear laboratory
Paloš, Radek ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
This thesis deals with the issue of process optimization. Especially with two selected methods, Lean six sigma and TRIZ. Both of these methods are briefly described, especially we could find in this thesis chapters about history, options of usage, and description of selected tools for realization. The thesis also deals with the comparison between methods, including their advantages and disadvantages. The next part of the thesis is about process mapping of preparation before testing electrical devices in the UVEE department FEEC laboratory, which is part of BUT. Except process map, there is an analysis of each process, evaluation, and future possible optimization.
|
|
|
Warming disconnector with earthing switch, type QAKZ, 17 kV, 8000 A
Matoušek, Jiří ; Šimek, David (referee) ; Bušov, Bohuslav (advisor)
This Bachelor’s thesis deals with issues related to heating in context of electrical apparatus. This bachelor’s thesis describes products manufactured by IVEP a.s. Especially indoor disconnectors are described in greater detail. Term that are relevant in context of temperature rise test are also describes in this thesis. These terms are taken from Czech technical standards. Mathematical model of temperature rise test is solved in this thesis. Results of mathematical model are then compared to experimental measurement of disconnector warming.
|
|
|
Short-circuit resistance of the disconnector KBE, 38 kV, 3150 A
Šťastná, Antonie ; Šimek, David (referee) ; Bušov, Bohuslav (advisor)
The bachelor's thesis is focused on the calculations of electrodynamic forces and short-term warming for the disconnector of the company IVEP a.s. within the framework of the issue of short-circuit resistance. The first part contains a theoretical summary of high voltage switching devices, their division and functions. The next part describes the problem of short-circuit currents, and the third part contains an introduction to IVEP devices. In the fourth part, essential information affecting the short-circuit resistance test of the KBE disconnector, 38 kV, 3150 A, is selected and described from the relevant standards related to the topic of the thesis. The main part of the thesis is devoted to calculations of electrodynamic forces affecting on the relevant disconnector and calculation of short-term heating in critical places of the current-carrying path. In the thesis, the achieved results are commented on and possible adjustments are suggested in case of inequality with the standards.
|
|
|
An effect of natural phenomena on electrical devices
Müller, Michal ; Aubrecht, Vladimír (referee) ; Bušov, Bohuslav (advisor)
The Thesis deals with the impact of natural effects on electrical equipment. It describes the various natural effects and shows how it impacts, what it impacts on and what the source of its impact is. The main point of this Thesis is the issue of atmospheric charge (storm and lightning) and the issue of coronal mass ejection (CME). The Thesis shows causally consequences string of geomagnetical field disturbances and resultant power system impacts. There are mentioned historic storm events and power system impacts and description of events in Hydro-Quebec – the most important event. Of this species. At the end there are shows possible way of mitigation power system impacts.
|
|
|
Calculation of electrodynamic forces acting on current path of a switching device
Benčo, Tomáš ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
The master thesis is focused on the calculation of electrodynamic forces acting on the contacts of the moulded case circuit breaker Siemens 3VA5 from OEZ Letohrad. This work is divided into ten chapters. In the introductory chapter it is described why it is important to deal with the calculation of the electrodynamic forces and the design of the current path. The second chapter describes the problem of the origin and effect of electrodynamic forces on individual parts of the electrical device. The third chapter describes the parameters, properties and design of the 3VA5 Siemens circuit breaker. The fourth chapter describes the Finite Element Methods. The fifth chapter describes how to create a 3D current path model in Solidworks. The sixth to ninth chapter is focused on the stationary calculation of moments in the program Ansys Maxwell by means of Magnetostatic Analysis and on the calculation of the total repulsive force between contacts with the influence of ferromagnetic materials. The last chapter is focused on dynamic calculation of moments and forces acting on contacts in a certain time interval.
|
|
|
Simulation of temperature-rise in MV switchgear assemblies
Kapalla, Alexej ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
This thesis focuses on the issue of heating of medium-voltage switchgears. The paper contains descriptions of the individual devices which the switchgear consists of. Furthermore, the paper examine the theoretical relations which describe the heating of the conductor. It also present the normative regulations regarding the heading of MV switchgears as well as specific impacts which influence the final temperature-rise. This is followed by chapters that describe the refining of a 3D model of specific switchgear for purposes of simulating temperature-rise, further followed by chapters that look at the actual simulation environment. The thesis further focuses on the actual simulation of MV switchgear temperature-rise and it will compare the results of the simulation with measurements taken under real conditions. The thesis also includes results of simulated temperature-rise while taking into consideration the forced cooling of the switchgear. In the last part, it focuses on the creation of an excel file, which enables the prediction of final results for the temperature-rise of disconnector based on its contact resistance.
|
|
|
Design of a 25 kV traction disconnector
Buchta, Martin ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
This diploma thesis deals with the design of a traction disconnector for 25 kV AC and a rated current of 800 A. The result should be a competitive disconnector that is capable of potential applications on domestic railways and should have parameters that other local manufacturers do not currently offer. This is, for example, electrical strength or the size of the rated current, which is an economic option for most railway lines in the Czech Republic. According to the proposed drawing documentation, the disconnector was assembled and then the selected disconnector parameters were tested. For example, electrical strength tests, short-circuit tests, constant current tests, etc. were performed. The calculated and measured values were compared together. The designed disconnector was financially and technically evaluated on the basis of test results and the construction itself. Finally, some appropriate adjustments were proposed.
|
|
|
Analysis of effects of short-circuit current in switchgear cabinet
Prokop, Jan ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
The work is focusing on dynamic effects of short-circuit currents, more precisely dynamic effects of short-circuit currents on switchgear cabinet (terminal box). The work was designated to a concrete construction type of two switchgear cabinets located on rotating machines via company Siemens Electric Machines Drásov s.r.o.. The switchgear cabinets are designed for non-explosive environment where the air is used as an insulating medium. The task was to determine how the device will behave during the three-phase short-circuit and three-phase short-circuit with earth/ground connection. The following programs were used for the calculations and simulations: Ansoft Maxwell 16.0, Ansoft Maxwell 2015 and ANSYS Workbench 16.0. By using these programs the effects of forces which acts on current paths in cabinet caused by the passage of short-circuit current were simulated, statically and also dynamically. Further the effects of pressure acting on cabinet frame during the arc short-circuit have been statically and dynamically simulated. All the results are summarized in the conclusion. Conclusion also contains the final evaluation of the functionality of both switchgear cabinets.
|
|
|
Contact erosion of switchgear under real conditions
Holoubek, Josef ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
This bachelor thesis is focused on the material loss - contacts erosion during switching process of the switchgears. First part is focused on the switchgears generally, their dividing and functions. Then there is closer look on the contacts of switchgears and what is necessary to be considered during their designing a operating. In this part there is also section devoted to the theory of the contacts erosion including the formulas for material loss calculation, which I found in existing literature. Practical part is focused on the contact system model and the measuring performed on this model. Measuring was also performed on the real switchgears for common use. There is also part devoted to this measuring. In the last part of thesis the analyze of the measured values is performed.
|
guest ::
