|
|
The Optimal Accuracy of Measurement Assurance in Accordance with Metrological Confirmation
Frank, Petr ; Kocman, Karel (referee) ; Nenadál, Jaroslav (referee) ; Hruška, Karel (advisor)
This thesis deals with the evaluation of accuracy of measurement and achieving the required accuracy level. This includes global analysis of the uncertainty evaluation, the calibration interval design and the creation of confirmation system. Basis of this work is in identification of all possible problems, which may occur during evaluation of accuracy and achieving the required accuracy level. The analysis is followed by suggested solutions for identified problems. It means namely the selection of probability distribution in case of uncertainty type A, evaluation of degrees of freedom in case of uncertainty type B, nonlinear correlation of input values, evaluation of coverage factor, the choice of method for calibration interval design and the procedure for meeting all metrological confirmation requirements. The last part of the thesis is practical measurement and result evaluation in the field of surge protection devices. This chapter demonstrates conclusions from the syntactical part.
|
|
|
Analysis of Ferroresonance Overvoltage in Electrical Net
Bátora, Branislav ; Eleschová,, Žaneta (referee) ; Krejčí, Petr (referee) ; Toman, Petr (advisor)
This thesis deals with the ferroresonance phenomenon and ferroresonance overvoltage in electric networks. That’s why the introduction part explains the theoretical basis of ferroresonance and its consequences in the power system. The work then focuses on the power system as a non-linear dynamic system and describes various analytical methods for solving these systems. These methods are further applied to diagnose specific systems. There are a number of various power system configurations susceptible to ferroresonance. The most frequent one is theoretically analyzed in this thesis and a number of recommendations are offered for reducing the ferroresonance phenomenon. The thesis further deals with the selection of suitable software for this computationally chal-lenging task. A number of different tools are considered and efficiently reduced to Matlab Sim-ulink and PSCAD software. Matlab Simulink and its SimPowerSystem Toolbox are used to ana-lyze the effect of hysteresis of the magnetic core of the transformer on the emergence and course of the ferroresonance phenomenon. Using PSCAD, various configurations of the power systems are compared in terms of possible emergence and course of ferroresonance and also to find the limiting conditions that increase the probability of this phenomenon. The possibility of using arti-ficial neural networks for ferroresonance diagnosis is also mentioned in this thesis. The final part provides a number of recommendations for design and operation of both new and existing power systems.
|
|
|
The quality of electric energy in a low voltage public supply networks
Vývoda, Marek ; Pithart, Jan (referee) ; Bok, Jaromír (advisor)
This thesis deals with description of qualitative parameters of supply voltage as well as measurement and data evaluation issues. Theoretical part of thesis describes basic characteristics of low voltage and limits based on standard specification. Next chapter deals with specification of measurement devices used for supply voltage quality measurement. The purpose of these theoretical parts is to introduce reader into supply voltage quality issues and can be used for preparation of measurement and acquired data evaluation under norm ČSN EN 50160 (Voltage characteristic of electricity supplied by public distribution systems). An analysis of real network is the last part of this thesis, in which application of acquired knowledge on assigment of real states of qualitative parameters of supply voltage in network.
|
|
| |
|
|
Fast Transient Phenomena in High Voltage
Vala, Martin ; Dohnal, Petr (referee) ; Krbal, Michal (advisor)
This work deals with research and description of the fast transients in high voltage technics. First part deals with division of fast transients and description of an impulse wave properties. Second part is focused on atmospheric overvoltage description and on direct and indirect lightning surge protection methods. Next, there are described the main characteristics and division of the surge protection devices in the work. In the next part, there are introduced some sort of high voltage generators, used for meassurement of impulse wave in a transmission line. In the last part there is stated an analysis of practical measurement of impulse weaves and surge arresters by using a Marx generator.
|
|
|
Planning and design electrical protection in the house wiring
Chromík, Aleš ; Mastný, Petr (referee) ; Bátora, Branislav (advisor)
The work includes familiarization with the problems of protection from injuries by electric current that includes individual protections and their use. In the work is also included effect of electric current on humans. Another point is the familiarization of protection against external and internal atmospheric surge in house wiring. Project risk analysis, against injuries to living beings by lightning strike, is calculated for the protection of atmospheric surge. The main point of this work deals with the procedure of design process of house wiring protections for given object. The project includes technical drawing, which contains how to design power and data distribution systems and switchgears, as well as the drafting of lightning system which accuracy is verified by the methods of protective angle and the ball rolling. Design and location of the right types of surge protection arresters is selected for a given objects. All project documentation is discussed in the technical report, which refers to existing standards.
|
|
|
Proposition of grounding enhancing cement composite mixture
Sochor, David ; Bydžovský, Jiří (referee) ; Drochytka, Rostislav (advisor)
The bachelor thesis deals with the design of a conductive cement composite grounding mixture for protection of building structures in areas with low conductivity. The theoretical part is mainly focused on summarizing the knowledge of the current protection of buildings against lightning and overvoltage. The study includes knowledge in the field of conductive building materials and aims to present the design of a cement composite mixture to improve grounding. Choosing the right raw materials to achieve electrical conductivity. A maintenance-free material has been developed, no humidity needed material while maintaining conductivity. The work it examines the possibilities of using industrial wastes as secondary raw materials. The conclusion focuses on laboratory testing of newly developed materials, summary and discussion of the results. With the developed samples, the resistivity was greatly reduced. The positive effect of ferric dust and carbon particles has been demonstrated.
|
|
|
The design of the lightning protection for the house
Tesař, Luděk ; Bátora, Branislav (referee) ; Toman, Petr (advisor)
This work describes the design rules for the lightning protection of civic construction. The aim of this work is to provide a comprehensive view of the basic design rules for the lightning protection. The actual design is preceded by the detailed introduction to the relatively large problems in this sphere. The introductory part is focused on the approach of technical standards and legislative requirements. In the second chapter the thesis deals with lightning in general and lightning current and its parameters. The following chapter focuses on the effects of lightning current, indicating the damage caused by lightning strikes to the building or its surroundings. Then the thesis deals with analysis and risk management. The next chapter describes and explains the system of external and internal lightning protection. The last part is devoted to a specific design of the lightning protection for the chosen house.
|
|
|
Application of surge protection in LV networks
Brtnický, Pavel ; Šlezingr, Jan (referee) ; Bátora, Branislav (advisor)
The work include the issues about surge protection in low voltage networks. The first part give a theoretical analysis of the surge protection, where is described own creation and basic division. The second part give a inner and outer protections, where is characterized, what protections contain and methods, with which to design protection. In the third part is few words about computer softwares, which supports dimensioning and design protections. The second half of the work give a specific design of protections for fire station, first there are determinated risks for building without surge protection and after for building under surge protection, design of outer protection together with verification and design of inner protection.
|
|
|
Způsoby ochrany elektronických komponent motorových vozidel
Němec, David
The bachelor’s thesis „Methods of protection of electronic components of motor vehicles“ in the introductory part acquaints the reader with electrical faults occurring in motor vehicles. The following section describes methods and means to protect against these faults. Furthermore, the work describes the current methods of protection of electronic control units and legislative requirements that impose obligations on manufacturers and suppliers in the design of protective devices for electronic modules of motor vehicles. The last part describes the means to protect the communication networks of motor vehicles against electromagnetic interference and electrostatic discharge.
|
guest ::
