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Differential protection of transformer.
Svoboda, Miloslav ; Paar, Martin (referee) ; Toman, Petr (advisor)
This bachelor thesis is divided into several chapters, which consist of two main parts of the work, theoretical and practical. In the theoretical part the work deals with disorders of electric network, causes and limit of their adverse effects. Further it theoretically analyses the function of electrical protection, requirements for the protection , their basic elements. Then there is described the principle and function of instrument transformers and the differential protection of transformers. The practical part of the work deals with protection for a specific transformer. The proposal involves the calculation of three-phase short-circuit, the selection of differential protection, the proposal of instrument transformers and settings of the protection function.
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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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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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Differential protection of transformer.
Svoboda, Miloslav ; Paar, Martin (referee) ; Toman, Petr (advisor)
This bachelor thesis is divided into several chapters, which consist of two main parts of the work, theoretical and practical. In the theoretical part the work deals with disorders of electric network, causes and limit of their adverse effects. Further it theoretically analyses the function of electrical protection, requirements for the protection , their basic elements. Then there is described the principle and function of instrument transformers and the differential protection of transformers. The practical part of the work deals with protection for a specific transformer. The proposal involves the calculation of three-phase short-circuit, the selection of differential protection, the proposal of instrument transformers and settings of the protection function.
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