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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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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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