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Coordination of operation of PST transformers in the interconnected region
Tesař, Jan ; Topolánek, David (referee) ; Bátora, Branislav (advisor)
This master’s thesis deals with phase-shifting transformers (PST) and coordination of electrically close devices in an interconnected region. Theoretical research is performed in the work, describing methods of power control, function and design of PST, as well as actual methods of PST coordination in the rest of the world. Based on the research there is an optimalisation algorithm designed in MATLAB, which computes recommended tap petting of PST based on the network configuration. In the second part of this thesis there are described components of this algorithm and also presented the results of three demonstrative scenarios. Algorithm is able to solve minor problems in the network; more complex problems are beyond its solving ability. For an improved functionality there is a necessity to further expand this algorithm by a network redispatch solving algorithm.
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Evaluation of MV/LV network earthing systems
Sítař, Martin ; Topolánek, David (referee) ; Kopička, Marek (advisor)
This master's thesis deals with the measurement of grounding systems in HV/LV distribution networks, which includes grounding system of distribution substation and transmission lines. Explores the issue and principles for the measurement of parameters, which are important for the protection of persons and animals in order not to touch exposed conductive part accidentally, protection of electrical machines and equipment against high fault current and dangerous surges while the correct function of the connected electrical equipment is maintained. These parameters include earth potential rise, ground resistance, soil resistivity, touch voltage, step voltage and transferred potential to the LV network. The aim of this work is the preparation, analysis and subsequent evaluation for the real measurement in practice. These earthing-system measurements were carried out at the distribution station and the concrete pole with a section disconnector. Then a numerical model of the grounding system of concrete pole was created in ANSYS. Subsequent evaluation of the results as numerical terms (comparison measurements and simulated results) and evaluation in terms of analytical (measurement results compliance with the standard) including the numerical model of the earthing system is solved in the practical part of the master's thesis.
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Load flow analyses of reactive power in distribution system
Krátký, Michal ; Kašpírek,, Martn (referee) ; Topolánek, David (advisor)
This thesis is focused on issues with transmission of reactive power though the distribution line of E.ON area. The goal is to find out where and in what rate are overflows of reactive power and to project the correctional steps to minimize this overflow. In this solution, there were used data of dispatcher measurement, which were processed by created source code in Matlab. The processing was analyzed for final conclusion. There were discovered shortages in overflow of reactive power in transfer between distribution and transmission line and in unsuitably regulated capacity power factor in Planá power plant and wrong automatic regulation of turns in 440/110kV substation Dasný. The action to minimize overflows of reactive power was projected by decompensation reactor placed in T101 and T102 transformers in substation Tábor.
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Evaluation of possibilities for voltage control in a LV distribution network
Bolgár, Robert ; Drápela, Jiří (referee) ; Topolánek, David (advisor)
This paper deals with possible ways of voltage regulation. Theoretical part includes a search of published methods and the available voltage regulators. Acquired theoretical knowledge has been applied in the development of mathematical models of two selected controllers applied to the testing network. The result of this work is a summary of the outcomes of dynamic simulations with two selected regulators at various locations in testing network. Comparing the results of dynamic simulation for two selected states was chosen the most appropriate regulator and its optimal location in testing network.
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Verification of the Vdip method on the physical model of the MV network
Krčál, Vít ; Drápela, Jiří (referee) ; Topolánek, David (advisor)
This Master's thesis is focused on creating of an algorithm which calculates changes of negative-sequence voltages and currents from their instantaneous values. That allows to conduct localization of asymmetrical faults in MV network in line with the Vdip method, which is based on monitoring the changes of negative-sequence components at distribution substations and at a sub-transmission station. The algorithm is being developed in Matlab environment with continuous implementation of partial procedures which are being assessed and compared with each other. A study of phasor estimating methods is carried out with pointing out related problems which are mainly caused by Ripple control and deviation of system frequency from its nominal value. Optimization precautions are designed to mitigate these problems. For elimination of the Ripple control effects a method based on averaging is presented. The deviation of system frequency is dealt with by resampling the original data recordings. The analysis processes are tested by both simulation signals and real measured data. The optimized algorithm enables precise calculation of negative-sequence components changes which is the main contribution of this thesis. The constructed algorithm is used in verification of the Vdip method on physical model of MV network. For these purposes a simple distribution network is created within which ground faults on different places and with different resistances are realised. The results of localization are not convincing which is mainly caused by specific features of laboratory power line models which are constructed with heterogenous parameters.
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Overhead Line Protection against Climatic Effects
Sýkora, Martin ; Topolánek, David (referee) ; Orságová, Jaroslava (advisor)
The outdoor overhead lines are influenced by additional load pressure of wind and frost. These can have adverse reaction on outdoor conduction of the electric power. My bachelors' report deals with separate climatic effects and possibilities of their resolution. It it also concentrates on removing the negative influences caused particularly by wind and on the possibilities of liquidation of the frost that had already originated.
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Autonomic fault recorder designed for a distribution transformer station MV/LV
Gaborčík, Michal ; Drápela, Jiří (referee) ; Topolánek, David (advisor)
This master’s thesis deals with realization of fault recorder designed for a distribution transformer station. In theoretical part is created research about operation of distribution transformer stations and about analytic methods, which gives bases for fault detection in power network. The practical part consists of design and realization of fault recorder in LabVIEW interface using CompactDAQ measurement platform. Purpose of this recorder is monitoring and recording of voltage and current waveforms on secondary side of transformer station during the fault in high voltage network. Principle of fault detection is primarily based on level monitoring of voltage negative symmetrical component. Fault recorder has been successively optimized and the final version is presented in this thesis. At the end functionality of designed system is evaluated on simulated fault in a model of high voltage network.
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Energy meter testing by test set CMC 256plus
Jurka, Tomáš ; Topolánek, David (referee) ; Toman, Petr (advisor)
The thesis provides a reader with a brief overview of the basic methods for measuring active electric quantities, development and types of energy meters. Some of the standards related to the energy meters are also included. Then follows the description of tests concerning both electrome-chanical and electronic meters of accuracy class number two. The thesis also includes a brief overview of energy meter testing devices from other producers. The next section describes test set OMICRON CMC 256plus and Test Universe program. The main part of the thesis consists of the scheme and the implementation of laboratory work for testing the energy meters with test set OMICRON CMC 256plus.
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Short Circuit Calculation of MV Grid
Knápková, Dagmar ; Topolánek, David (referee) ; Toman, Petr (advisor)
This bachelor’s thesis deals with the faults in the distribution networks, focusing on shortcircuits as the most common and the most signiĄcant types of faults. The thesis is divided into theoretical and practical part. In the theoretical introduction, describes the types of faults in distribution networks with a focus on the short-circiuts, their causes, and the impact on distribution networks. Follows a description of the time course of short-circuit currents, short-circuit calculation simpliĄcation assumptions, the formula for calculating the impedance of the various elements of the short-circuits schema and the calculation methods of short-circuit currents in accordance with ČSN EN 60909-0. In the practical part, there is an example of the calculation of simple network conĄguration. Follows an analysis of the real network, including the analysis of the method of operation and the selection of appropriate method for the calculation of the short-circuit. After that are carried out practical calculations short-circuit conditions in four places on the network, and three diferent types of short circuits. For one-phase short-circuit is subsequently carried out the distribution of currents in a parallel branch of the distribution lines. At the conclusion of the bachelor’s thesis is caried out evaluation the results and analysis of the data obtained by calculation.
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