National Repository of Grey Literature 6 records found  Search took 0.00 seconds. 
Design of overvoltage protection for the object with explosive risk
Polášek, Roman ; Novotný, Jan (referee) ; Bátora, Branislav (advisor)
This master´s thesis deals with the designing process of surge protection for the object potentially explosive atmospheres and according to a set of standards ČEN EN 62305 and ČSN EN 60079. This work consists of four main parts. The first part deals with the theory of lightning and surges. Subsequently, in the second part is devoted to the theory of protection against these phenomena and proposals for external and internal lightning protection and surge. This chapter also deals with more demands on electrical installations in hazardous areas. The third part deals with the analysis of the risks to the subject paint and according to ČSN EN 62305-2 ed.2 and at the conclusion of the study is a proposal for external lightning protection and internal surge protection.
Surge Arrester Installation in The Industrial Network
Korejčík, Michal ; Šlezingr, Jan (referee) ; Orságová, Jaroslava (advisor)
The work deals with issues of transient overvoltages. The first part of the work is focused on the overvoltages generating during switching actions. Overvoltage, which is arising during interrupting small inductive current, is practically tested by program ATP. Next part of this work is engaged in an area of atmospheric overvoltages. There are described typical characteristics and parameters of atmospheric overvoltages. The following chapter is devoted to high-voltage surge arresters - the elements, which avert danger of serious equipment damage. Spark-gap arresters as well as MO-arresters are described in this work. Their general characteristics and typical parameters are being introduced. Finally, the last part of the work explains the concept of protective distance and the equation, after whose is protective distance determined. The concept is verified by the help of program ATP, in which it is possible to simulate the phenomena arising from the transient overvoltages.
Dynamic Model of Medium Voltage Vacuum Circuit Breaker and Induction Motor for Switching Transients Simulation using Clarke Transformation
Pígl, Jan ; Bernat,, Petr (referee) ; Ferková, Želmíra (referee) ; Cipín, Radoslav (advisor)
Derivation of the dynamic model of medium voltage vacuum circuit breaker and induction motor in space vectors in coordinates 0 allow us to model switching transients in various dynamic states of the motor. In the case of the Clarke transformation, the corresponding numerical integration technique can be selected including variable time-step integration techniques to avoid numerical instabilities due to the stiffness of the system. Assymetrical operations such as switching cause that power system becomes unbalanced and the transformed equations , and 0 are not uncoupled. Therefore it is necessary to derive a coupling matrix between circuit breaker voltages and currents in the coordinate system 0. The behavior of the dynamic model was experimentally verified on a laboratory model during the transition between balanced and unbalanced states of the system. The subject of our interest are switching overvoltages that arise when turning off small inductive currents by a vacuum circuit breaker. When deriving the model of a vacuum circuit breaker, all its properties encountered during this action were taken into account, i.e. current chop, virtual current chop, dielectric barrier in the circuit breaker and its recovery rate and the ability of the vacuum circuit breaker to extinguish high frequency currents. Dynamic model is further extended by overvoltage protections and frequency-dependent line model. Simulation results are compared with the measured results on a medium voltage motor and as well as with the simulation results of the mathematical model of the test circuit according to IEC 62271-110 resolved using nodal method (EMTP algorithm). Models are implemented in the MATLAB/Simulink programming environment.
Measuring System for Registration of Atmospheric and Switch Overvoltages in Electrical Power Network
Potáček, Lukáš ; Mišák,, Stanislav (referee) ; Kolcunova,, Iraida (referee) ; Baxant, Petr (advisor)
This thesis is oriented to a specific section of energetics concerned with detection and registration of time responses of fast overvoltages in high-voltage power networks. The first part of this text is information about measuring frequency response characteristics of CR-divider and calculation of typical signal distortion caused by transfer function of this divider. The design of anti-aliasing filter is also included. The second part of this thesis is oriented to selecting key features of a measuring instrument specialized for detecting and recording fast events in electrical power networks. A selection of optimal type of processor and also a choice of communication interfaces is included there as well. The last chapter prepares mathematical procedures for classification of typical fast events in electrical power network using artificial neural networks.
Surge Arrester Installation in The Industrial Network
Korejčík, Michal ; Šlezingr, Jan (referee) ; Orságová, Jaroslava (advisor)
The work deals with issues of transient overvoltages. The first part of the work is focused on the overvoltages generating during switching actions. Overvoltage, which is arising during interrupting small inductive current, is practically tested by program ATP. Next part of this work is engaged in an area of atmospheric overvoltages. There are described typical characteristics and parameters of atmospheric overvoltages. The following chapter is devoted to high-voltage surge arresters - the elements, which avert danger of serious equipment damage. Spark-gap arresters as well as MO-arresters are described in this work. Their general characteristics and typical parameters are being introduced. Finally, the last part of the work explains the concept of protective distance and the equation, after whose is protective distance determined. The concept is verified by the help of program ATP, in which it is possible to simulate the phenomena arising from the transient overvoltages.
Design of overvoltage protection for the object with explosive risk
Polášek, Roman ; Novotný, Jan (referee) ; Bátora, Branislav (advisor)
This master´s thesis deals with the designing process of surge protection for the object potentially explosive atmospheres and according to a set of standards ČEN EN 62305 and ČSN EN 60079. This work consists of four main parts. The first part deals with the theory of lightning and surges. Subsequently, in the second part is devoted to the theory of protection against these phenomena and proposals for external and internal lightning protection and surge. This chapter also deals with more demands on electrical installations in hazardous areas. The third part deals with the analysis of the risks to the subject paint and according to ČSN EN 62305-2 ed.2 and at the conclusion of the study is a proposal for external lightning protection and internal surge protection.

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