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Analysis ofelectrical output from the power plat working in the middle of town
Hrubý, Radek ; Brno,, Luděk Ondroušek - Teplárny (referee) ; Matoušek, Antonín (advisor)
The work focuses on outlet of the electrical power from power plants operating in urban areas. After a short analysis of the general possibility of leading out electric power from power plants of various types, thesis continues to describe of outlet electrical power from PPC Červený Mlýn. Subsequently, are calculated short-circuit conditions in the main switching station. It follows an analysis of power lines. The last part dealt with the issue of reliability of sources in connection with random transition processes in the electrical network and the light of the operational reliability of electrical power equipment.
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Design of technical measures in LV distribution network with a high value of short-circuit currents
Šmehlík, Daniel ; Bátora, Branislav (referee) ; Ptáček, Michal (advisor)
This bachelor thesis discusses the sizing and the possibility of reducing large short circuit ratios. For a specific scheme of an industrial building, which will be fed from three transformers, the sizing will be done by means of the SICHR program. The specific objective of the technical solution is to be able to use modular circuit breakers with a ripping capability of short-circuit currents up to 10 kA in the terminal switchboards. Another objective of the work is to perform an economic evaluation of the proposed solution, or to optimize the design from the point of view of the economic aspect in meeting the technical requirements.
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Short Circuit Currents in the Sokolnice 400 kV Switching Station with Direct 400/110 kV Transformation Applied
Vojtěch, Pavel ; Špaček, Jaroslav (referee) ; Blažek, Vladimír (advisor)
The destination of this Bachelor´s Thesis is to explore short circuit currents for voltage level 400 kV in the switching station Sokolnice before year 1995 and after this year, when came to installation of the convertor T402 and to voltage direct 400/110 kV transformation applied. The Thesis is detecting at relation as for three-phase short circuit do for single-phase short circuits, for 400/220/110 kV primary transformation variation in voltage and for variation 400/110 kV, the change which came after connection of the convertor T402. In base of this calculation will be explored the short circuit resistance rating switching station in agreement with parameters ordered by the comp. Inc. ČEZ Prague.
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Short circuit current of synchronous generator
Šebesta, Ondřej ; Orságová, Jaroslava (referee) ; Toman, Petr (advisor)
The thesis deals with the problematics of short-circuit current of synchronous machine. The first section focuses on the theoretical process of short-circuit current of synchronous machine and describes how this transient process changes throughout it's duration and with what reactances and time constants it is defined. Subsequently, this section deals with the methodics of tests of the snychronous machine,which may be used to set it's reactances. The second part of the work focuses on measurement of the short-circuit current in a specific synchronous machine. Further, there are measurements of processes of the short-circuit in time and their analysis. The last section of the thesis deals with the simulation of short-circuit current process. The simulation is ran by the Matlab/Simulink software. Simulated processes of short-circuit are then compared with the results of measurements from the previous section of the thesis.
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Load Flow Calculation and Design of Distance Protection Relay Settings of 110 kV Overhead Line
Jasenský, Filip ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Bachelor thesis load flow calculation and design of distance protection relay settings of 110 kV overhead line acquaints with the theory calculation of steady operation, short-circuit conditions and a proposal setting the distance protection. The theoretical part is made an example of a simple calculation to show leadership methods of calculation. The practical part is a calculation of steady operation and short-circuit conditions. Short-circuit ratios are calculated for a single operation and parallel operation of transformers in Otrokovice. Calculated using the initial shock symmetrical output from the calculation of short-circuit conditions is verified by short circuit resistance of substations. The practical section setting the distance protection ABB REL 316*4 and compensation earth faults. Calculation of steady state and short-circuit conditions designed basic operational state of the network, for which the design of a distance protection relay settings.
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Replacement of electromechanical protections in TNS Vraňany
Čechová, Karolína ; Šiler, Michal (referee) ; Orságová, Jaroslava (advisor)
The reconstruction of the traction substation Vraňany currently involves only the replacement of power oil transformers. The main reason for their replacement is the fact that the power transformers have already exceeded their designed lifecycle. According to an investor requirement, only the transformer replacement is considered, however, a new system of protection is not included. Even though the fault-free operation of power transformers is closely related to ensuring a reliable and safe electric power supply. The main aim of the thesis is to design a new system of protection for power transformers to replace the present one. In the theoretical part of the thesis is described the current state of the traction substation along with a calculation of short circuit current ratios and their comparison with the new ones considering the installation of the new power transformers. In the next part are inspected instrument current transformers if they comply with the requirements for the new protection system. The practical part of the thesis focuses on the selection of protection relay, calculation of the primary setting for selected protection functions, and subsequently conducting their functional tests. In conclusion, the economic part of the planned investment is estimated.
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Calculation of short circuit currents in electtrical network
Reiter, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
First chapters of my bachelor´s thesis are focused on failures of networks, simple characteristics and description of their potential danger. Next chapters are thoroughly focused on the short-circuit, on the short-circuits graphs, on the circumstances which caused them and on their calculation. Next part is about the example, which is counted by the IEC 60909. First example is simple network. Second example is real distribution network 110kV. We are going to cogitate two involves for the real network and we are going to calculate symmetrical and asymmetrical short circuit current. There is summary of knowledge about the short-circuits and evaluation of the real distribution network at the end of my thesis.
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The calculation of the short-circuit currents and voltages of given distribution network
Vyčítal, Václav ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
This thesis deals with the transient phenomena in electric power systems especially short circuits. Than short circuit is classified to other types of faults in electric power system. The study also describes short circuit current as a function of time. However to complete a basic theory of short circuits, separate chapters are devoted to the causes of short circuits and to hazards connected with short circuit currents. The main part of this paper is devoted to the derivation of the formulas for calculation of short circuit currents using symetrical components and to calculation method presented in IEC 60909. In the end of this part there is a example of a simple network with calculation of symetrical and asymetrical short circuit current. In the last part of this thesis there is an example of 110 kV network with calculation of short circuits currents on busbars. The topology of the network and elekctrical equipment data are based on real part of a distribution network situated in the Czech Republic.
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Power supply of electrostatic separator
Broďák, Kamil ; Pazdera, Ivo (referee) ; Huták, Petr (advisor)
The diploma thesis focuses on the problems of electric power precipitators. Due to their current dominant position, the work concentrates on the sources of single phase transformers operating at the frequency of 50 Hz controlled by thyristors. The first part describes the electrostatic precipitator and its principle. This is followed by a brief insight into the proposal for an electrostatic precipitator. The work also explains the high voltage source that is divided into a transformer with a rectifier and into a control box with power circuits and control circuits that provide the power supplied by a transformer. The work also offers an explanation of the HV source system that operates at different conditions. The last part suggests a proposal for cooling cabinet including thyristors, for power line control box resources, for a supply line and a line to the transformer.
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