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Program for calculating the resistance of earthing systems
Gura, Roman ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
The bachelor’s thesis addresses the issue of grounding systems, which are essential for the safety and reliability of electrical installations. The aim of this thesis is to develop a software tool for calculating the parameters of grounding systems based on their geometric dimensions, in accordance with corporations’ norms. Resulting program automates the calculations using an intuitive graphic interface including the display of the system.
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Testing of the protection in the substation model on the physical model of the distribution system
Pražák, Ondřej ; Topolánek, David (referee) ; Jurák, Viktor (advisor)
This thesis discusses different types of distribution-systems, theirs grounding methods, ground faults and how to be protected against them. This paper also desribes earth fault protection in terminals ABB (REF615, REX640), their principle, functions, settings and also manner which they are conected to distribution-system model with description of control program settings called PMC600, all gained knowlege is verified via tests on distribution system model
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Evaluation of Voltage Events from COMTRADE Records
Poul, Martin ; Topolánek, David (referee) ; Krčál, Vít (advisor)
The bachelor thesis focuses on the evaluation and detection of voltage events and rapid voltage changes according to ČSN EN 61000-4-30 and their statistical evaluation. The thesis describes the monitored voltage characteristics used for detection and evaluation, primarily based on the standard describing the quality of electrical energy ČSN EN 50160. The work includes a program developed for the detection and evaluation of these events. Using the program, voltage events from real operation of 22 and 110 kV power grids are evaluated.
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Validation of the tool for localization of symmetrical and asymmetrical faults
Šmehlík, Daniel ; Jurák, Viktor (referee) ; Topolánek, David (advisor)
Disturbances in power systems that can cause widespread outages and limit power supply require rapid detection, location and elimination. Earth faults and short circuits, each with their own complications for localization, pose significant challenges to power operations. This thesis focuses on the validation of Vdip, a tool designed to efficiently locate these faults. The tool was tested in two simulation environments, RTDS and PSCAD, to simulate different fault scenarios and record data for analysis. These tests provided important information for evaluating the effectiveness of Vdip.
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Localization of short-circuits on single side supplied HV line
Zíka, Jakub ; Jurák, Viktor (referee) ; Topolánek, David (advisor)
This bachelor‘s thesis deals with the localization of unilaterally fed short circuits on high voltage lines. The first part of the bachelor’s thesis deals with the research of the localization of unilaterally fed 1-Phase, 2-Phase and 3-Phase short circuits on the HV lines. Furthermore, individual types of short circuits are described here with suitable procedures for calculating the fault distance and definition of formulas for individual impedance loops. The second part of the bachelor’s thesis focuses on the implementation of these formulas for calculating the distance to the fault location. The input values of voltages and currents were simulated by a simple system model in the PSCAD program. Subsequently, a more detailed sensitivity analysis of individual types of short-circuits was carried out and possible detection of when individual calculation methods fail.
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Touch voltages and earth surface potentials of selected earthing systems designs
Novodomec, Radim ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
The aim of the bachelor’s thesis was to investigate the influence of the shape, size, placement of earthing systems designes as well as the influence of the soil model on the size of the resulting potential and touch voltage during the passage of ground current. For the construction and subsuquent simulation of these phenomena, the Ansys Maxwell Desktop program was used, which is suitable for using the finite element method, as the use of analytical methods is demanding. The results were further processed in Excel into graphs. The resulting touch voltage was determined as the difference between the maximum potential of the earthing system and the potential at distance of 1 meter.
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Testing of the experimental model of the distribution system 22 kV
Musil, Milan ; Topolánek, David (referee) ; Novotný, Jan (advisor)
The aim of this project is practical verification and finding of the main parameters of model elements (lines, transformer, suppresion coil). This supresion is needed for eventual model testing of faults that might occur in the configured distribution network. The measurement was done using the equivalent model and computing zero-sequence impedance or admittance and their parts. Also it was necessary to find out the parameters of transformer, which consisted of a force measurement. Another part of thesis deals with the proposal of the new model elements. The most important of them is the model of switch, witch needed to protect model and the surroundings during nonstandart network conditions (faults).
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Simulation of earthing system resistance measurement
Pirochta, Josef ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
In this bachelor thesis, the effect of different soil models and random wire placed underground on the results of earth resistance measurements using the 4-pole method was investigated. To determine this influence, simulations were performed in Ansys Electronics software, in which different soil models (with local inhomogeneity, horizontally divided soil and soil divided at an angle) were created. In these models, the measured earth was placed together with the measured random wire and its resistance was determined by simulating the measurements and with respect to the distant ground. The effect of the different soil models on the accuracy of the measurements was determined from the differences in the resistance of the earth random wire obtained by measurement and with respect to the distant ground. It was found by simulations that, of all the variants investigated, performing measurements in the presence of different soil models and a random wire can lead to a measurement error of up to 7,2 %.
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Testing of Distance Protection
Řehoř, Jiří ; Topolánek, David (referee) ; Orságová, Jaroslava (advisor)
The testing of distance protection in bachelor´s task is made a distinction between protection, requirements and relegation. This testing is also consisted in principle of function, describing terms of distance protection and comparing with time-current characteristics. The next step after short estimation was describing digital distance protection SIPROTEC 7SA511. The advantages are included in this estimation. The next part contains some configurations and connections with a test equipment in order to take control of measuring through the computer. The extended configurations are also comprised of two programms – DIGSY and TZO3. We had to make a suggestion of suitable methodics for measuring a time-current characteristic. We carried out three measurements where the test equipment was set to role of type TREND. A magnitude is generated at the output that is changed linearly in time with required rate (speed). We changed a current IX1 for our measurements that was undertaken with a rate of current rise. This process was given by a test equipment when the set values were constant. In the second measurement we modified a size of shift phase in the test equipment. In the third measurement we tried to set up different sizes of particular impedance characteristics (zone) inside of the distance protection where was set a neutral breaking time for the measured zone. On the contrary, the previous measurements had an absolute time.We have introduced evaluated results of measuring and observations in the end of this bachelor’s thesis.
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