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Overloading and short circuits of electric wires
Jurman, Jiří ; Valenta, Jiří (referee) ; Šimek, David (advisor)
The bachelor's thesis discusses the requirements that must be met in practice for electrical distribution systems in terms of the construction and securing of electrical distribution systems against the effects of current overload and conductor shorts according to the relevant Czech and European standards. Furthermore, the work marginally focuses on standardized thicknesses and materials used precisely for insulation. From the point of view of residential wiring of Czech residential distributors and distributor's homes, to compare different conditions in terms of requirements for wires connected to electricity meters. Furthermore, the work certainly refers to programs that are used in practice for the design of electrical elements and conductors for specified electrical parameters based on the parameters themselves, such as the consumption of equipment connected to the electrical distribution. In the thesis, we can find some programs used in practice for this purpose, including a description of their functions and a subsequent comparison of these programs and a model design using a program used in practice. Finally, the thesis evaluates the performed measurement of the influence of the released Joule integral determined using the K2S2 value and, in the second part, determined by the limiting class of the circuit breaker.
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Proposal of electrical equipment for soaking and drying cores for making castings
Čermák, Jiří ; Hájek, Vítězslav (referee) ; Veselka, František (advisor)
This diploma thesis deals with proposal of electrical equipment for soaking and drying cores for making castings at foundry in a Great Britain. It brings look at system of technical norms ČSN and it compares it with british system of technical norms British standards. The second part of this thesis contains detailed proposal of this equipment, including specification of control system, specification of power supply cables and control cables and particular technological units. The whole project documentation is enclosed as an inseparable attachment of this diploma thesis.
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Design of technical measures in LV distribution network with a high value of short-circuit currents
Šmehlík, Daniel ; Bátora, Branislav (referee) ; Ptáček, Michal (advisor)
This bachelor thesis discusses the sizing and the possibility of reducing large short circuit ratios. For a specific scheme of an industrial building, which will be fed from three transformers, the sizing will be done by means of the SICHR program. The specific objective of the technical solution is to be able to use modular circuit breakers with a ripping capability of short-circuit currents up to 10 kA in the terminal switchboards. Another objective of the work is to perform an economic evaluation of the proposed solution, or to optimize the design from the point of view of the economic aspect in meeting the technical requirements.
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Comparison of free available software for the calculation of electric network parameters
Dvořák, Radim ; Janík, Daniel (referee) ; Ptáček, Michal (advisor)
The aim of this bachelor thesis is to compare freely available software for calculating the parameters of electrical networks. The first part is used to give an idea how to operate in the programs Sichr, DOC, Spider (xSpider) and ~ SIMARIS design and their evaluation in terms of usability, requirements, graphical interface and controllability. Furthermore, a technical analysis of specific topologies of specified distribution networks is performed in the work. In the second part, the calculation of network parameters was performed using the SW above. Finally, the realized calculations of voltage drops and short-circuit currents using individual programs were compared with each one another.
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Protective measure - automatic disconnection of suply
Leitner, David ; Vaněk, Jaromír (referee) ; Valenta, Jiří (advisor)
The aim of this thesis is to explain the principle of automatic disconnection of supply, which is one of the basic protective measures for security assurance in electric installations of low voltage according to the new issue of Czech Technical Standard (ČSN 33 2000-4-41 ed. 2). Furthermore, the relevant clauses of the Czech Technical Standard in the new and previous issues are compared, with focus on the problem of automatic disconnection of supply in basic types of distribution networks. In agreement with theoretical conclusions, a project of electric energy supply system is proposed in the practical part of the thesis. Special attention is paid to showing the methods of modeling and verification of conditions for automatic disconnection of supply, with using control calculations in the SICHR program. Finally, the fulfillment of the conditions for automatic disconnection of supply is verified by revising the electrical supply system.
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Design of technical measures in LV distribution network with a high value of short-circuit currents
Šmehlík, Daniel ; Bátora, Branislav (referee) ; Ptáček, Michal (advisor)
This bachelor thesis discusses the sizing and the possibility of reducing large short circuit ratios. For a specific scheme of an industrial building, which will be fed from three transformers, the sizing will be done by means of the SICHR program. The specific objective of the technical solution is to be able to use modular circuit breakers with a ripping capability of short-circuit currents up to 10 kA in the terminal switchboards. Another objective of the work is to perform an economic evaluation of the proposed solution, or to optimize the design from the point of view of the economic aspect in meeting the technical requirements.
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Comparison of free available software for the calculation of electric network parameters
Dvořák, Radim ; Janík, Daniel (referee) ; Ptáček, Michal (advisor)
The aim of this bachelor thesis is to compare freely available software for calculating the parameters of electrical networks. The first part is used to give an idea how to operate in the programs Sichr, DOC, Spider (xSpider) and ~ SIMARIS design and their evaluation in terms of usability, requirements, graphical interface and controllability. Furthermore, a technical analysis of specific topologies of specified distribution networks is performed in the work. In the second part, the calculation of network parameters was performed using the SW above. Finally, the realized calculations of voltage drops and short-circuit currents using individual programs were compared with each one another.
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Proposal of electrical equipment for soaking and drying cores for making castings
Čermák, Jiří ; Hájek, Vítězslav (referee) ; Veselka, František (advisor)
This diploma thesis deals with proposal of electrical equipment for soaking and drying cores for making castings at foundry in a Great Britain. It brings look at system of technical norms ČSN and it compares it with british system of technical norms British standards. The second part of this thesis contains detailed proposal of this equipment, including specification of control system, specification of power supply cables and control cables and particular technological units. The whole project documentation is enclosed as an inseparable attachment of this diploma thesis.
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Protective measure - automatic disconnection of suply
Leitner, David ; Vaněk, Jaromír (referee) ; Valenta, Jiří (advisor)
The aim of this thesis is to explain the principle of automatic disconnection of supply, which is one of the basic protective measures for security assurance in electric installations of low voltage according to the new issue of Czech Technical Standard (ČSN 33 2000-4-41 ed. 2). Furthermore, the relevant clauses of the Czech Technical Standard in the new and previous issues are compared, with focus on the problem of automatic disconnection of supply in basic types of distribution networks. In agreement with theoretical conclusions, a project of electric energy supply system is proposed in the practical part of the thesis. Special attention is paid to showing the methods of modeling and verification of conditions for automatic disconnection of supply, with using control calculations in the SICHR program. Finally, the fulfillment of the conditions for automatic disconnection of supply is verified by revising the electrical supply system.
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