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Individual stand-by of incoming feeder of Energetika Trinecs´ 6 kV substation
Borski, Roman ; Hodula, Petr (referee) ; Topolánek, David (advisor)
The thesis titled Individual stand-by of incoming feeder of Energetika Třinec 6 kV substantion is theoreticaly and practically concived work that offers comprehensive information on automatic standby focused on the selected operation of Energetika Třinec. At present, the standby is in authention mode and thesis solves shutdown of transformer T5. The extract of automatic device indicates trouble-free operation and thesis focus on the power take-off for transformer T5. The theoretical part provides information about problems of own comsumption of power plants, automatic device of standby and protection of electrical equipment. Thesis also sloves the protection settings, which is supported by calculations of short-circuit currents. The practical part is formed from the suggestion of solution in accordance to current criteria and the evaluation of possible settings of protective automatic devices together with an assessment of implementation option of standby. The aim of the thesis is to perform analysis of standby and evaluate effects which causes shutdown of own comsumption part. The final part assesses current settings of protection based on calculated values. Existing protections are unsuitable and it is recomennded to deploy digital multi-stage protections as a replacement for present relay protections.
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Comparison of Instrument Transformers and Current Sensors with Respect to the Function of Differential Protection
Rajchman, Zbyněk ; Topolánek, David (referee) ; Orságová, Jaroslava (advisor)
Current transformers and current sensors are devices which are mostly used for current measurement in high voltage systems. These devices transform measured currents to range which are workable for measurement and protection devices. Theoretical part includes from third to seventh chapter. These chapters contain construction analysis and characteristic points for both device and problems of protecting the transformer with differential protection. Practical part includes from eighth to tenth chapter. This chapter consists results from laboratory measurement. Results are used for verification with theoretical part of the thesis. Conclusion of this thesis comparing properties and summarises results from laboratory measurement.
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Protection setting concept for given MV substation
Váhala, Václav ; Holub, Jiří (referee) ; Topolánek, David (advisor)
The thesis is focused on the protection concept for medium voltage substation. The first theoretical part of thesis describes given medium voltage substation. Substation consists of two incoming feeders and six outgoing feeders. Due to the size of the substation was selected one outgoing feeder which is the subject of description and protection concept. Next part of the thesis is a description of the protective functions used to protect the elements in the selected feeder. This part contains a detailed description of the function and setting options for protection. The main part of the thesis describes calculation of specific protection functions and consequently with secondary testing of protective functions. Tests were performed on protective functions in the digital protections REF615 and REM620. The final part of the thesis deals with the evaluation of the secondary test results and verification saturation of the specified current transformers.
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Development of the tool for application of the method for localization of unsymmetrical faults
Pospíšil, Tomáš ; Vyčítal, Václav (referee) ; Topolánek, David (advisor)
In resonant earthed distribution systems, the capacitive current of the system is compensated by grounding via a arc suppression coil. The level of fault current is then very small and independent on the fault location which greatly complicates the rapid finding of the fault site. At this moment there is no method to be used to directly locate the site of a single-phase fault in the distribution network, new methods and solutions are being constantly sought to address the shortcomings of the existent localization methods. The diploma thesis deals with the design of a universal software tool that allows to apply a new method of locating an asymmetric fault in the distribution network. The tool is created in a MATLAB environment and utilizes the negative sequence voltage measured on the low-voltage sides of the distribution transformers and the negative sequence current measured behind the power transformer. By using the proposed tool, it is possible to read the parameters of any part of the distribution system that the user enters together with the measured values of the voltage and current into the initialization file. After the specified network parameters are loaded, a numerical model is created, which is then used for the method. In the work is described in detail the way of entering the parameters of the network into the initialization file, the method of automatic assembling of the numerical model based on the entered data and the possibility of customizing the calculation parameters. At the end of the thesis, the functionality of the proposed software tool is verified on data from simulation of the test network.
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Voltage quality index for distribution systems voltage quality benchmarking
Hausner, Josef ; Topolánek, David (referee) ; Drápela, Jiří (advisor)
This Master’s thesis deals with design of a new method for voltage quality benchmarking using voltage quality index. This index should determinate total voltage quality in the power grid and compare voltage quality in different places. There is design of several algorithms which value measured parameters in this thesis. The best suitable algorithm is selected. Program for this algorithm was compiled in GUI Matlab. The algorithm is verified by using measured parameters in this program. The last part of this thesis is focused on possible usage of created algorithm.
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Utilization of SINCAL tool in the field of network protection
Rampák, Dominik ; Wasserbauer, Vojtěch (referee) ; Topolánek, David (advisor)
This bachelor thesis is describing the basics of using program PSS SINCAL for protection of distribution networks. The thesis is divided into 3 parts. The first part is describing basics and functions of the program. The second part is devoted to the moduls, work with moduls described in form of manuals. The last part is describing creation of test network and simulation of single-phase to ground short-circuit to verify selectivity of the protection devices.
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Steady state calculation of 22kV network
Kaplanová, Klára ; Opat, Jaroslav (referee) ; Topolánek, David (advisor)
Master's thesis proposes a new operation state of distribution network 22kV in Prostějov district after connection of the new Prostějov – Západ substation. The PASS DAISY OFF-LINE Bizon program is used to calculate power losses, optimal network possibilities, as well as to create a new model of Prostějov district's distribution network and to design a modification of a current state of given location. A description of this calculating and simulation program is also included in this paper. The theoretical part describes calculating methods of distribution network’s condition, with emphasis on mathematical method used by PASS DAISY OFF-LINE Bizon program, the modified Newton-Raphson method. The aim of this paper is to prepare technical documentation for E.ON company, with respect to new operation disconnection, planned overhead and cable lines of corresponding parameters. These changes in network's configuration will cause a new distribution of feeding areas. As a result, related changes of provided power from individual feeding points and changes of power currents in electric lines will occur. Due to new operation connection, a reduction of losses and, simultaneously, an improvement of voltage ratios are expected. One of the aims of this paper is to update network's model in PASS DAISY OFF-LINE Bizon program to match the current network’s state of a given area. The outcome of this work is a comparison between the current condition and the new operation condition, with new Prostějov – Západ substation connected, from perspective of distribution network's operator.
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Distribution of short circuit currents and voltages in unsymmetrical faults
Kakrda, Michal ; Topolánek, David (referee) ; Haluzík, Evžen (advisor)
The objective of this bachelor thesis is to introduce the calculation of voltage and current ratios in asymmetrical short circuits. The first part of the thesis is focused on delineating the problem of short circuits in general. It describes the causes of short circuit arising, the types of short circuits and their processes. The next part of the thesis shows the ways of calculating particular types of short circuits, namely concentrating on the method of symmetrical components. The last part of the thesis is focused on the application of the discovered findings to calculate the ratios for the particular electric network. The calculation has been made for all the types of short circuits, both symmetrical and asymmetrical. The resulting ratios are recorded into the phasor diagrams for particular types of short circuits. The part of the calculation is also the recalculation of phase currents through a transformer.
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Testing of the admitance principle of the fault indicator
Musil, Milan ; Vyčítal, Václav (referee) ; Topolánek, David (advisor)
The thesis deals with the proposal, implementation and evaluation of test for fault condition indicators. Thesis focusing on earth fault indicators based on admittance principles. These indicators must be able to evaluate earth faults in compensated, compensated with auxiliary resistor, unearthed and high-resistance earthed networks. The proposed tests verify the current and voltage measurement errors in inputs including monitored characteristic variables such as conductance and susceptance. The proposed test are applied to a selected ample of the fault indicator. As part of the tests, the indicator is subjected to secondary test using the Omicron CMC256plus tester as well as test on fault records that have been converted to COMTRADE for this purpose. The last series of tests carried out uses the physical model of the medium voltage system, where the tested equipment is subjected to fault states in the compensated whit auxiliary resistor system and isolated system. Furthermore, part of the thesis is research of new methods of earth fault detection, including their principles and function description. Also included in the thesis is an overview of manufacturers of indicators, or protection, who are involved in the production of earth fault protection.
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Current Transformers and Current Sensors Confrontation
Popek, Jiří ; Bok, Jaromír (referee) ; Topolánek, David (advisor)
Current transformers and current sensors are devices which are mostly used for current measurement in high voltage systems. This devices transform measured currents to range which are workable for measurement and protection devices. Current transformers have been using for current measurement since electric system was built. Current sensors are using for measurement after applying digital devices in their secondary circuits. Theoretical part includes fourth and fifth chapter. These chapters contain construction analysis and characteristic points for both devices. Practical part is in chapter six. This chapter consists results from laboratory measurement. Results are used for verification with theoretical part of the thesis. Accuracy class in nominal range and progress for measurement error in overcurrent range was verified for tested devices. Conclusion of this thesis comparing properties and summarises results from laboratory measurement.
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