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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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Field test of feeder protection ABB REF615 using an experimental model of 22kV distribution system
Váhala, Václav ; Orságová, Jaroslava (referee) ; Topolánek, David (advisor)
The main purpose of the bachelor thesis is to describe, preset and verify function of digital protection ABB REF615. The thesis is focused on detailed description from the protection function and hardware configurations point of view. The thesis also informs about parameters of experimental model of medium voltage distribution network. This model was used for operation testing of selected protection functions. First of tested function was admittance earth fault protection respectively conductance protection. This conductance principle is based on admittance protection function where only real part of zero sequence admittance is evaluated. Intermittent earth fault, phase directional over-current protection and circuit breaker failure protection were tested next. Evaluation of all test results is subject of the final part of the thesis.
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Design of instrument transformers for digital protection relays
Souček, Jan ; Matuška, Marcel (referee) ; Toman, Petr (advisor)
Master’s thesis is concerned with instrument transformers, which are used in conjunction with numerical protection relays. Therefore mainly with protective transformers of class P and transformers dimensioned for transient effects, which are important e.g. for fast differential or distance protections. The introduction includes fundamental notions, quantities and equations, which refers to instrumental current and voltage transformers. Below are mentioned connection diagrams of these transformers applied to specific electrical network types and faults, of which identification is required. These diagrams and faults are supplied with math equations and eventually with phasor diagrams. Noted informations corresponds to the present standards. Task of the next part is to compile requirements for dimensioning of current transformers, which imposes digital protections from ABB, AREVA and Siemens companies. These requirements, which mostly defines the minimal accuracy limit factor or the knee-point voltage of current transformer, are specified for individual protection terminals, eventually for specific protective functions. Part of the thesis is computer program developed as macro in the Microsoft Office Excel program via Visual Basic for Applications programming language. Program uses equations noted in this work and it can be used for quick dimensioning of current transformers for protective terminals from manufactures mentioned above.
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Protection functions of the REX 640 terminal in case of earth faults
Siegel, Josef ; Bukvišová, Zuzana (referee) ; Wasserbauer, Vojtěch (advisor)
This bachelor thesis deals with the protection, implementation and evaluation of test for fault condition indicators. Thesis focus on earth fault indicators. These protections must be able to evaluate earth faults in compensated, compensated with auxiliary resistor, unearthed and high-resistance earthed networks. Furthermore, part of the thesis is research of methods of earth fault detection, including their principles and function description.
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Protection functions of the REX 640 terminal in case of earth faults
Siegel, Josef ; Bukvišová, Zuzana (referee) ; Wasserbauer, Vojtěch (advisor)
This bachelor thesis deals with the protection, implementation and evaluation of test for fault condition indicators. Thesis focus on earth fault indicators. These protections must be able to evaluate earth faults in compensated, compensated with auxiliary resistor, unearthed and high-resistance earthed networks. Furthermore, part of the thesis is research of methods of earth fault detection, including their principles and function description.
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Field test of feeder protection ABB REF615 using an experimental model of 22kV distribution system
Váhala, Václav ; Orságová, Jaroslava (referee) ; Topolánek, David (advisor)
The main purpose of the bachelor thesis is to describe, preset and verify function of digital protection ABB REF615. The thesis is focused on detailed description from the protection function and hardware configurations point of view. The thesis also informs about parameters of experimental model of medium voltage distribution network. This model was used for operation testing of selected protection functions. First of tested function was admittance earth fault protection respectively conductance protection. This conductance principle is based on admittance protection function where only real part of zero sequence admittance is evaluated. Intermittent earth fault, phase directional over-current protection and circuit breaker failure protection were tested next. Evaluation of all test results is subject of the final part of the thesis.
|
|
|
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.
|
|
|
Design of instrument transformers for digital protection relays
Souček, Jan ; Matuška, Marcel (referee) ; Toman, Petr (advisor)
Master’s thesis is concerned with instrument transformers, which are used in conjunction with numerical protection relays. Therefore mainly with protective transformers of class P and transformers dimensioned for transient effects, which are important e.g. for fast differential or distance protections. The introduction includes fundamental notions, quantities and equations, which refers to instrumental current and voltage transformers. Below are mentioned connection diagrams of these transformers applied to specific electrical network types and faults, of which identification is required. These diagrams and faults are supplied with math equations and eventually with phasor diagrams. Noted informations corresponds to the present standards. Task of the next part is to compile requirements for dimensioning of current transformers, which imposes digital protections from ABB, AREVA and Siemens companies. These requirements, which mostly defines the minimal accuracy limit factor or the knee-point voltage of current transformer, are specified for individual protection terminals, eventually for specific protective functions. Part of the thesis is computer program developed as macro in the Microsoft Office Excel program via Visual Basic for Applications programming language. Program uses equations noted in this work and it can be used for quick dimensioning of current transformers for protective terminals from manufactures mentioned above.
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