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Simulation of Broken Conductor in Distribution Network by ATP-EMTP Program
Pacula, Václav ; Novotný, Jan (referee) ; Paar, Martin (advisor)
When broken conductor will impact on the ground. In isolated networks to ground fault occurs. For fault detection is the most commonly used method of zero-sequence voltage. The principle of the method is the sum of the voltage in all phases in the symmetric systém is the sum zero. The aim is to compare this method with the method of symmetrical sequence method and timeshiftomg. The method of symmetrical sequences compares sequency currents. To change the status of the systemis changed period, this method is based on the time shift.For comparison is used the ATP-EMTP program, that simulates the electrical transients. In this program are designed network model in which, these methods are investigated. It is a simple model of an idealized model and part of distribution network. After the simulation waveforms of events are processed and the results found faultdetection. Protection used today are based on measurements of zero-sequence voltage. A newer method of protection that extends further the possibility of detection and localization.
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Steady state and short-circuit conditions in 110kV E.ON network fed from Sokolnice transformer station
Vyčítal, Václav ; Rampl, Martin (referee) ; Blažek, Vladimír (advisor)
This thesis can be divided into five main parts. The first part deals with theoretical analysis of power flow calculation in power network during steady state condition. Load flow calculation is presented here as a linear and nonlinear problem. Newton iteration method is proposed for solving power flow as nonlinear problem. The second part of this thesis deals with the analysis of short-circuit calculation in accordance with valid International Standard IEC 60909. The equivalent voltage source method is adopted in case of the short-circuit calculation. For the calculation of unbalanced short-circuit currents, the symmetrical components method is also presented. The last three parts of this paper are focused on calculations of power flow and short-circuit conditions in power grid Sokolnice. So in the third part is the description of nodal area Sokolnice with its substations and the calculation of load flow and short-circuit conditions for two different power supply options. For each supply option is also considered an abnormal (fault) grid condition. (overall there are solved four different options) The fourth part of this thesis deals with the result analysis and also the results of different power supply options are compared. In the last part there are presented necessary technical improvements for fault-free operation of power grid Sokolnice based on the result of power flow and short-circuit conditions in that grid.
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Short - circuit conditions at Sokolnice 110 kV switching station following a direct 400/110 kV transformation
Hajdú, Lukáš ; Paar, Martin (referee) ; Blažek, Vladimír (advisor)
The goal of this bachelor´s thesis is to evaluate short-circuit conditions at the Sokolnice 110kV switching station before and after installation of a T402 transformer – before and after application of a direct 400/110kV transformation. By evaluating these conditions determine whether the originally installed protective elements (power circuit-breakers) are capable of fulfilling the new short-circuit requirements at the switching station. The thesis consists of two parts: the first part introduces the theory required to evaluate the short-circuit conditions at the switching station, while the second part calculates the actual short-circuit currents and power outputs. The methods used for calculation are sequential simplification and symmetrical components.
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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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Short-circuit Calculation of Local Distribution Network
Byrtus, Jiří ; Paar, Martin (referee) ; Topolánek, David (advisor)
This thesis deals with transient phenomena in the electricity grid - especially with short-circuits. First part describes short-circuit types, reasons for their commencement and also consequences of their functioning. The thesis further shows waveforms of short-circuit currents and its components. A method of calculating short-circuits currents, using the constituent systems and the basic equations for calculating short-circuit impedances are also mentioned here. Relations and methods are based on valid standards of IEC 60909 – 0. The second part indicates the calculation of two-phase and three-phase short-circuit currents for specific network of industrial building. This calculation aims to verify the dimensioning of substations for short-circuit currents after connecting a synchronous generator with given power to the main substation.
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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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Stabilized operation and short - circuit conditions within E.ON 110 kV power network supplied from Otrokovice 110kV switching station, during the period of 2011
Jurča, Ondřej ; Rampl, Martin (referee) ; Blažek, Vladimír (advisor)
Distribution network 110 kV owned by E. ON in the area Otrokovice; powered by 110 kV and two variants of involvement contained.The first option is basic involvement, without the use of the bridge. The second option includes involvement with the bridge. The aim of this study is to compare; by calculating the steady-state network operation and short circuit conditions of the network, the involvement of these two options. The thesis is divided into two parts, theoretical and practical. The theoretical part consists of a description of the steady operation of networks of high-voltage and short circuit ratio calculations. Load flow calculations are described by the Gauss-Seidel and Newton iterative method. In the case of short-circuit conditions, the effects of their characteristic values, processes and various methods of calculation are described.In the second part, this theoretical knowledge is applied to input data and dispatching programme with the appropriate calculations of network operation and short circuit conditions. The calculated values are listed in the thesis, on the basis of which an evaluation of the two possible connections is made.
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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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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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Simulation of Broken Conductor in Distribution Network by ATP-EMTP Program
Pacula, Václav ; Novotný, Jan (referee) ; Paar, Martin (advisor)
When broken conductor will impact on the ground. In isolated networks to ground fault occurs. For fault detection is the most commonly used method of zero-sequence voltage. The principle of the method is the sum of the voltage in all phases in the symmetric systém is the sum zero. The aim is to compare this method with the method of symmetrical sequence method and timeshiftomg. The method of symmetrical sequences compares sequency currents. To change the status of the systemis changed period, this method is based on the time shift.For comparison is used the ATP-EMTP program, that simulates the electrical transients. In this program are designed network model in which, these methods are investigated. It is a simple model of an idealized model and part of distribution network. After the simulation waveforms of events are processed and the results found faultdetection. Protection used today are based on measurements of zero-sequence voltage. A newer method of protection that extends further the possibility of detection and localization.
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