|
|
Selection and Application of Surge Arresters for Middle-Voltage Air-Insulated Switchgears
Němec, Ondřej ; Bernard, Michal (referee) ; Drápela, Jiří (advisor)
The purpose of this thesis is to introduce readers with design of a surge arresters in four different categories. In the first part of this thesis is described theory of overvoltage, surge arresters and testing. The second part of this thesis is focused on design of surge arresters to protect from overvoltage due switching capacitive loads. The thesis continued with design of surge arresters in medium voltage network. The next part is design of surge arresters to protect from overvoltage due switching inductive loads. The next point is protective distance of surge arresters in different lighting overvoltages. In the conclusion of this thesis is the appreciation of whole problems about surge arresters.
|
|
|
Design of overvoltage arresters in high voltage switchgear depending up parameters of connected load
Němec, Ondřej ; Bernard, Michal (referee) ; Lázničková, Ilona (advisor)
The purpose of this thesis is to introduce the reader about the problems of design of surge arresters. The first part of this thesis describes problems of surge. In the next part of this thesis are described test pulses needed to test surge arresters. The next issues of this thesis are medium voltage switchgears and surge arresters ABB and their test. In the next part ot this thesis are described type of network according earthing of transformers. The other point of this thesis are aplications of surge arresters, figures and calculation for networks, generators, transformers and motors. In the conclusion of this thesis is the appreciation of whole problems about surge arresters.
|
|
|
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.
|
|
|
Design of overvoltage arresters in high voltage switchgear depending up parameters of connected load
Němec, Ondřej ; Bernard, Michal (referee) ; Lázničková, Ilona (advisor)
The purpose of this thesis is to introduce the reader about the problems of design of surge arresters. The first part of this thesis describes problems of surge. In the next part of this thesis are described test pulses needed to test surge arresters. The next issues of this thesis are medium voltage switchgears and surge arresters ABB and their test. In the next part ot this thesis are described type of network according earthing of transformers. The other point of this thesis are aplications of surge arresters, figures and calculation for networks, generators, transformers and motors. In the conclusion of this thesis is the appreciation of whole problems about surge arresters.
|
|
|
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.
|
|
|
Selection and Application of Surge Arresters for Middle-Voltage Air-Insulated Switchgears
Němec, Ondřej ; Bernard, Michal (referee) ; Drápela, Jiří (advisor)
The purpose of this thesis is to introduce readers with design of a surge arresters in four different categories. In the first part of this thesis is described theory of overvoltage, surge arresters and testing. The second part of this thesis is focused on design of surge arresters to protect from overvoltage due switching capacitive loads. The thesis continued with design of surge arresters in medium voltage network. The next part is design of surge arresters to protect from overvoltage due switching inductive loads. The next point is protective distance of surge arresters in different lighting overvoltages. In the conclusion of this thesis is the appreciation of whole problems about surge arresters.
|
guest ::
