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Touch voltages and earth surface potentials of selected earthing systems designs
Novodomec, Radim ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
The aim of the bachelor’s thesis was to investigate the influence of the shape, size, placement of earthing systems designes as well as the influence of the soil model on the size of the resulting potential and touch voltage during the passage of ground current. For the construction and subsuquent simulation of these phenomena, the Ansys Maxwell Desktop program was used, which is suitable for using the finite element method, as the use of analytical methods is demanding. The results were further processed in Excel into graphs. The resulting touch voltage was determined as the difference between the maximum potential of the earthing system and the potential at distance of 1 meter.
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Calculation and technical solutions earthing system of transformer substation 110/22 kV
Mašek, Jakub ; Dušek, Igor (referee) ; Bátora, Branislav (advisor)
Master's thesis deals with principles of design of earthing of a substation 110/22 kV. Specific requirements for safety have to be fulfilled when designing power installations exceeding 1kV. The aim of this paper is to design a new earthing system for reconstructed substation 110/22kV considering valid standards. Reconstruction of a property is always more or less complicated by new orders and regulations for construction. Earthing is a part of all electric equipment, therefore it is essential for the design engineer to consider a broad spectrum of requirements, even those seemingly not related to this subject, from legislative requirements to the study of reactions of a human body to electric current. The theoretical part of this work examines different approaches to earthing system's design, and analyzes the origins and earthing standards throughout history. The correctness in consideration of effects of the environment is an often neglected factor. Defining of all types of effects of the environment is a broad field, therefore this paper only summarizes the main principles. The practical part of this paper deals with the basic design of substation's earthing system and it's verification in respect of touch voltage and step voltage according to the Czech national standard ČSN 33 3201 (Power installations exceeding 1kV a.c.) and of company's energetics' standard PNE 33 0000-1 ed.4 (Protection against electric shock in distribution network and transmission system) required by the substation's distributor. This paper later quotes and takes into consideration the requirements of other standards, more or less related to listed documents, creating an interconnected body for design and testing the earthing system.
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The measurements of earthing systems and the role of electrical soil resistivity
Capyk, Jan ; Jurák, Viktor (referee) ; Vyčítal, Václav (advisor)
The theoretical part of the thesis is focused on explaining the concept of soil resistivity, applicable methods of its measurement, comparison of two methods used to measure the resistance of the earth electrode and a description of the measuring device Metro PU 193 used for the practical part of the thesis. In the practical part, the reader is acquainted with the results of measuring soil resistivity and earth resistance in the field, with their evaluation with respect to various influencing factors and with designs of earth conductors for high voltage poles for which soil resistivity was measured. The thesis contains plotted graphs of various dependencies according to the results of measured values and compares them with theoretical assumptions.
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Documentation for construction of new distribution transformer station and cables line HV a LV
Matouš, Milan ; Orságová, Jaroslava (referee) ; Bátora, Branislav (advisor)
The following master thesis is devoted to the design of distribution systems of LV (Low Voltage) and HV (High Voltage) voltage levels. The aim of the thesis is to create a complete project documentation for the construction of a new distribution transformer station (22kV/0.4kV) situated directly in the city of Blansko along with a transformer capable of performance of up to 630kVA. Subsequently a design of cable routes of LV and HV is included in the project documentation. The first part of the thesis introduces the fundamental issues and solutions regarding the design of electrical equipment related to the LV and HV voltage levels. Thereafter it deals with proper legislation, technical regulations and related standards. The second part is dealing with project documentation. More precisely analyzing each step in the process and thoroughly going through individual parts of the project documentation. Other focus of the thesis is software resources and tools which are essential for drawing documentation. Then follows a selection of appropriate electrical equipment and budget evaluation. The major portion of the work is a design of distribution transformer station and cable lines of LV and HV. Including dimensioning of the LV and HV switchboards, earthing system and fuse protection system. The essence of all this work serves as a foundation for complete design documentation.
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Project of Earthing System in 110/22 kV Transfornmation Station
Pavlík, Ludvík ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This Thesis is concerned with the concept of grounding of 110/22 kV transformer station. The aim of the Thesis is to create a ground network for grounding a specified outdoor substation. This 110 kV outdoor substation is formed according to H-scheme and encircles a wide area. In additon to this, an earth potential has to be distributed as equally as possible within the whole area of the substation. The most convenient alternative from the point of view of effective grounding and distribution of potential is a grid network. Therefore, the grid network is the means of grounding which I have chosen as a solution for this issue. In this solution, flat conductor network cables are used to cover the whole substation, with ground rods placed at the points of intersection. Parts of appliance can be then connected to this existing network, thus creating several parallel channels which provide grounding with low resistance. The network is made of common steel zinc-coated stip, size 30 x 4 mm. When proposing a concept of grounding and adjustment of ground electrodes, we have to take account of grounding requirements, stated according to ČSN standards. The proposed earthing system was created in appropriate size in order to meet all these grounding requirements. These requirements are also mentioned and described in a theoretical part of the Thesis. Second part of the Thesis consists of proposed concept of the grounding itself, together with calculated parameters. The grounding has to be carried out according to both safety regulations and electrical appliance requirements. The issue of grounding substations of power system is resolved by the ČSN standards 33 3201 (“Elektrické instalace nad AC 1kV”), 33 2000-4-41 (“Elektrická zařízení – Ochrana před úrazem elektrickým proudem”) and 33 2000-5-54 (“Elektrická zařízení – Výběr a stavba elektrických zařízení – Uzemnění a ochranné vodiče”) and by the PNE company standards 33 0000-4 (“Příklady výpočtů uzemňovacích soustav v distribuční a přenosové soustavě dodavatele elektřiny”) and 33 0000-1 (“Ochrana před úrazem elektrickým proudem v distribuční soustavě dodavatele elektřiny”). These standards apply to creating a concept of grounding and grounding of new, reconstructed or expanded electrical substations of power system.
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Problems of measurement and evaluation of earth resistance
Šindelář, Petr ; Janda, Marcel (referee) ; Veselka, František (advisor)
This work deals with the measurement of earth resistance, definition, substances causing earth conductivity, basic norms for carrying out grounding revisions and effect of earth resistance on securing and protection element. In the introduction there is theoretical analyzing of grounding issue and principles for the measurement of parameters, which are important for the protection of persons and animals in order not to touch exposed conductive part accidentally, protection of equipment against high fault current and dangerous surges while the correct function of the connected electrical equipment. In the next part there are described methods of earth resistance and soil resistivity measuring. The practical part of the work summarizes the results of practical measurements in individual places with different measuring device.
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Touch voltages and earth surface potentials of selected earthing systems designs
Novodomec, Radim ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
The aim of the bachelor’s thesis was to investigate the influence of the shape, size, placement of earthing systems designes as well as the influence of the soil model on the size of the resulting potential and touch voltage during the passage of ground current. For the construction and subsuquent simulation of these phenomena, the Ansys Maxwell Desktop program was used, which is suitable for using the finite element method, as the use of analytical methods is demanding. The results were further processed in Excel into graphs. The resulting touch voltage was determined as the difference between the maximum potential of the earthing system and the potential at distance of 1 meter.
|
|
|
The measurements of earthing systems and the role of electrical soil resistivity
Capyk, Jan ; Jurák, Viktor (referee) ; Vyčítal, Václav (advisor)
The theoretical part of the thesis is focused on explaining the concept of soil resistivity, applicable methods of its measurement, comparison of two methods used to measure the resistance of the earth electrode and a description of the measuring device Metro PU 193 used for the practical part of the thesis. In the practical part, the reader is acquainted with the results of measuring soil resistivity and earth resistance in the field, with their evaluation with respect to various influencing factors and with designs of earth conductors for high voltage poles for which soil resistivity was measured. The thesis contains plotted graphs of various dependencies according to the results of measured values and compares them with theoretical assumptions.
|
|
|
Problems of measurement and evaluation of earth resistance
Šindelář, Petr ; Janda, Marcel (referee) ; Veselka, František (advisor)
This work deals with the measurement of earth resistance, definition, substances causing earth conductivity, basic norms for carrying out grounding revisions and effect of earth resistance on securing and protection element. In the introduction there is theoretical analyzing of grounding issue and principles for the measurement of parameters, which are important for the protection of persons and animals in order not to touch exposed conductive part accidentally, protection of equipment against high fault current and dangerous surges while the correct function of the connected electrical equipment. In the next part there are described methods of earth resistance and soil resistivity measuring. The practical part of the work summarizes the results of practical measurements in individual places with different measuring device.
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Documentation for construction of new distribution transformer station and cables line HV a LV
Matouš, Milan ; Orságová, Jaroslava (referee) ; Bátora, Branislav (advisor)
The following master thesis is devoted to the design of distribution systems of LV (Low Voltage) and HV (High Voltage) voltage levels. The aim of the thesis is to create a complete project documentation for the construction of a new distribution transformer station (22kV/0.4kV) situated directly in the city of Blansko along with a transformer capable of performance of up to 630kVA. Subsequently a design of cable routes of LV and HV is included in the project documentation. The first part of the thesis introduces the fundamental issues and solutions regarding the design of electrical equipment related to the LV and HV voltage levels. Thereafter it deals with proper legislation, technical regulations and related standards. The second part is dealing with project documentation. More precisely analyzing each step in the process and thoroughly going through individual parts of the project documentation. Other focus of the thesis is software resources and tools which are essential for drawing documentation. Then follows a selection of appropriate electrical equipment and budget evaluation. The major portion of the work is a design of distribution transformer station and cable lines of LV and HV. Including dimensioning of the LV and HV switchboards, earthing system and fuse protection system. The essence of all this work serves as a foundation for complete design documentation.
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