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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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Design of a transformer station for power output from a PV power plant and a diesel generator
Marák, Jiří ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This thesis is about design of a transformation station for power output from both a photovoltaic power plant and a diesel generator, serving as grid support. The primary objective is to devise a comprehensive solution including conceptualization, grid connection point, and transformer specifications capable of handling the 5 MW power output from the PV plant and the 1000 kW output from the diesel generator, including the calculation of short-circuit conditions. Furthermore, the thesis delves into the design of network breakpoints and protective measures.Lastly, it proposes dispatch control and billing metering in accordance with the operational requirements stipulated by the distribution system operator.
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Validation of the tool for localization of symmetrical and asymmetrical faults
Šmehlík, Daniel ; Jurák, Viktor (referee) ; Topolánek, David (advisor)
Disturbances in power systems that can cause widespread outages and limit power supply require rapid detection, location and elimination. Earth faults and short circuits, each with their own complications for localization, pose significant challenges to power operations. This thesis focuses on the validation of Vdip, a tool designed to efficiently locate these faults. The tool was tested in two simulation environments, RTDS and PSCAD, to simulate different fault scenarios and record data for analysis. These tests provided important information for evaluating the effectiveness of Vdip.
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Localization of short-circuits on single side supplied HV line
Zíka, Jakub ; Jurák, Viktor (referee) ; Topolánek, David (advisor)
This bachelor‘s thesis deals with the localization of unilaterally fed short circuits on high voltage lines. The first part of the bachelor’s thesis deals with the research of the localization of unilaterally fed 1-Phase, 2-Phase and 3-Phase short circuits on the HV lines. Furthermore, individual types of short circuits are described here with suitable procedures for calculating the fault distance and definition of formulas for individual impedance loops. The second part of the bachelor’s thesis focuses on the implementation of these formulas for calculating the distance to the fault location. The input values of voltages and currents were simulated by a simple system model in the PSCAD program. Subsequently, a more detailed sensitivity analysis of individual types of short-circuits was carried out and possible detection of when individual calculation methods fail.
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Evaluation of pressure conditions in the quenching chamber of low-voltage device
Nevrzal, Filip ; Vávra, Daniel (referee) ; Valenta, Jiří (advisor)
In this master’s thesis there is firstly conducted research about pressure measurement. Next there is mathematical description of thermodynamic conditions in used testing chamber by using magnetohydrodynamic and Maxwell equations. Next chapter deals with testing chamber itself, more precisely with function, model and changes done to it. In practical part there are data measured by used sensors, which are also closer described in this chapter. In next chapter there is comparison of reaction times of used sensors and their frequency specters, obtaining using fast Fourier transformation. Second to last chapter introduces very measurement on the real device and in the last chapter these data are analyzed and more closely described.
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Design of a 22 kV network in the Lipno area after the integration of the new 110/22 kV transformer station
Žižlavský, Jakub ; Koudelka, Jan (referee) ; Ptáček, Michal (advisor)
This diploma thesis deals with the design of a new 110/22 kV substation in Horní Planá. The substation design addresses, for example, the issue of reducing the load of surrounding power lines from 110/22 kV substations, reducing the size of short-circuit ratios in the surrounding system, reliability and continuity of supply, etc. Furthermore, loads of individual outgoing feeders from the surrounding substations are analyzed, in case they will be connected to a new substation. Following this, the work also addresses the related new decay points of the lines, which are determined by calculation and simulation in the Grizzly program. The simulation results could be used to compare the current load status of individual lines and contribute to the assessment of the possible benefits of both the new substation and the implementation of other modern technologies for faster and more efficient measurement and handling during operating and fault conditions.
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Line protection against overload and short circuit
Konšel, Ladislav ; Vaněk, Jaromír (referee) ; Valenta, Jiří (advisor)
This work includes a theoretical treatise on the operation of electrical wiring for the overload and short circuit. This is mainly on thermal effects of over current and their influence on the properties of conductors and insulation. Work Includes links to determine the load current, depending on the properties of leadership and its surroundings. It also deals with the protection of conductors against overload and short circuit. The work includes measurements process of warming wires. Practical project of proposal circuit is created using SICHR. The project includes proposals of conductor’s sizes and safety components for both residential building and individual flats.
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High-voltage/low-voltage prefabricated substantions
Loveček, Michal ; Šafránek, Ivan (referee) ; Haluzík, Evžen (advisor)
The diploma thesis is dedicated to modern kiosk-type transformer substations PET, that are used when modernizing distribution network. Since such substations are placed on publicly accessible places it is really important that they are safe for service staff as well as for the public. Apart from the highest characteristic values stress is put upon the safety. Right construction, functionality and safety is verified using the type-tests as stated in ČSN EN 62271-202. In the last part of the thesis there are the methods and procedures of type-testing described.
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Analysis of parallel operation of nodal areas of 110 kV Krasikov and Neznasov transformers stations
Kostkan, Petr ; Kopička, Marek (referee) ; Ptáček, Michal (advisor)
Currently, the nodal areas of Neznášov substation and Krasíkov substation, which belong to ČEZd distribution network 110 kV – East, are operand as separate units. In the defined setting, each nodal area comprises of two 400/110 kV transformers. In the case of failure of the transformer T401 or T402, the criterion N-1 for twenty percent of the rated output is not met. Such problem can be solved by parallel operation of nodal areas of Neznášov substation and Krasíkov substation. The principal as well as practical aim of this thesis is to interconnect the bridge operated connection in separated areas into parallel/loop operation of nodal areas (supplied by 400/110 kV transformers). Computing software is used to calculate the steady state and short-circuit conditions in the distribution network 110 kV for separate and parallel operation of mentioned nodal areas. Power flow analysis is aimed at assessment and evaluation of voltage conditions, transformers loading (400/110 kV and 110/vn) as well as 110 kV lines loading. Obtained short-circuit indices is used to examine short-circuit, withstand capability of the 110 kV substation. Finally, benefits as well as drawbacks of the separate and parallel operation are compared and evaluated. If necessary, the technical arrangements are proposed/designed in order to allow parallel operation of nodal areas Neznášov substation and Krasíkov substation.
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