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Project of Overhead Line
Chrástek, Radim ; Těžký, Jiří (referee) ; Orságová, Jaroslava (advisor)
Overhead line has to suit a series of requests, so that all its parts safely resist mechanical and electrical tension. This bachelor’s thesis deals with mechanical tension. At first, necessary overhead line’s relationships under different climatic conditions are deduced. Consequently, practical calculations are introduced. Calculations are done with Matlab program.
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Complex design of the overhead line section of the transmission system
Reiskup, Filip ; Valiga, Matěj (referee) ; Ptáček, Michal (advisor)
The aim of thesis is a design of overhead lines of transmission system under specific weather conditions in given area. Furthermore, it gives a summary about the transmission and distribution systems and describes basics of overhead lines, used conductors and pylons in Czech Republic. It also presents the issue of climate conditions having a eminent influence on overhead lines. Moreover, theoretical part of thesis contains conductor mechanics and also mentions asymmetric state of overhead lines. Practical part deals with a design of specific part of overhead lines at voltage level of 400 kV and generally evaluates area where lines would be operated. In this area the new power energy source is hypothetically planned and therefore thesis analyzes possible variants of connection this source to transmission system. For one of these variants there are the calculations of two sections of the overhead lines under different weather conditions in more detail. The results bring longitudinal profile and assembling table for each section and they demonstrate the major impact of icing on the overhead lines.
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Proposal of the reconstruction of a distribution network in a specific area
Richter, Miroslav ; Mrvová, Dana (referee) ; Blažek, Vladimír (advisor)
The dissertation describes several types of low and high voltage distribution networks including their implementation in specified location with regards to the reliability and quality of electric power supply. The distributions networks are classified according to ways of cable routing, distribution line voltage levels as well as according to types of network interconnections. The high and low voltage distribution networks are further categorized based on used cable types, where, more attention is paid to insulated lines used in the Czech Republic, low voltage lines called „AES“ and „PAS“ high voltage lines used more and more during the distribution network reconstruction. Attention is also given to the description of used methodology for the calculation of network performance stability. An individual part of the dissertation is devoted to a low voltage distribution network proposal in the village of Kovalovice. Based on performed analysis of distribution network conditions, several reconstruction versions were proposed with the help of „KASI“ software, the description of which is also included. The proposed versions are further analysed for both, technical and economical aspects and is selected most suitable version of the distribution network.
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Overhead Line Protection against Climatic Effects
Sýkora, Martin ; Topolánek, David (referee) ; Orságová, Jaroslava (advisor)
The outdoor overhead lines are influenced by additional load pressure of wind and frost. These can have adverse reaction on outdoor conduction of the electric power. My bachelors' report deals with separate climatic effects and possibilities of their resolution. It it also concentrates on removing the negative influences caused particularly by wind and on the possibilities of liquidation of the frost that had already originated.
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MV Overhead Line Protections and their Coordination with Autoreclosers
Šoustal, Petr ; Skala, Petr (referee) ; Orságová, Jaroslava (advisor)
The aim of this Master’s Thesis is to describe protections for overhead lines in distribution networks. Here are described requirements for the protection and the basic protections. Protections are divided according to their protective function. For each protection is given its use and its power plans. It is stated in the work setting of protection in the real network. On this network is simulated place with short-circuit and described the action of protection. The work also deals with the coordination of protection with automatic circuit breakers. This chapter shows that, given the selectivity is not possible to deploy two or more reclosers (remotely-operated switches) to the core network management. The next chapter describes two representatives reclosers available on the Czech market OSM 27 and GVR 27. Chapter describes and compares their performance characteristics. Conclusion the work includes a proposal protected the lead in incorporating automatic circuit breakers (remotely operated circuit breakers and reclosers). The proposal is based on two different levels of annual number of interruptions and duration of annual general interruption of electricity supply. For these levels the company EGÚ Brno, a.s. proposed several variants of the use of remote-controlled in terms of reducing the cost of the penalty. Our task was to choose a variant that would be applicable in the real network. Reducing costs is feasible only in the limits Ln = 6 failures / year and Lt = 720 min / year, where the selected option No. 4. The limits Ln = 8 failures / year and Lt = 1,080 min / year, not in the real network may no option in terms of selectivity.
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Dynamic loading of overhead lines
Šimák, Josef ; Jurák, Viktor (referee) ; Orságová, Jaroslava (advisor)
The bachelor's thesis is focused on the introduction of equipment and principles in dynamic current loading of lines. The individual methods are introduced and described with a focus on online monitoring systems. Furthermore, the calculation of the dependence of the parameters of AlFe conductors on the temperature change is performed.
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Analysis of Using Cable Sections in the Route of 400 kV Overhead Line
Belatka, Martin ; Rusek, Stanislav (referee) ; Modlitba, Petr (referee) ; Matoušek, Antonín (advisor)
The thesis deals with the use of cable sections in the overhead transmission route of the 400 kV transmission system in the Czech Republic, with the design of the arrangement of the cable route and with the solution of the crossover of the cable line with other networks of the technical infrastructure or natural obstacles. The thesis shows what the construction of a 400 kV cable line in the overhead transmission route - which has not been implemented in the Czech Republic as of yet - entails in practice. The first, general part deals with the electrical properties of both the cable lines and the combined overhead transmission lines with intermediate cable sections, and this sets out limitations on the maximum possible length of the cable sections. The following chapters provide an analysis of the magnetic field of the cable line, its impact on the surrounding environment and the possibilities of its shielding. On the basis of this knowledge optimization of the designed cable route arrangement is carried out in order to make the route comply with hygiene limits. The next part uses selected locations on a real route of overhead 400 kV transmission line to show what the construction of cable sections inserted into the route of overhead 400 kV line would involve. The design includes a professional estimate of the time and financial demands of the construction.
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Design of Protection Relays for MV Distribution Grid
Sochor, Tomáš ; Bukvišová, Zuzana (referee) ; Toman, Petr (advisor)
The master´s thesis deals with the design of medium voltage power line protection and the calculation of reliability indicators. First, it deals with the possibilities of power system operation. Subsequently, it divides the networks according to the grounding of the transformer node and the switching elements and devices occurring in the MV distribution network are mentioned. It presents the basic classification of power line protection and its use, especially it focuses on overhead and cable MV power lines. It also discusses the reliability of the power supply and lists the basic reliability indicators and their possible calculation. The practical part describes the changes in the considered area of the distribution network, where the reconstruction of the power line VN872 and a new way of powering the village Drnholec will take place. The impact of this change on the reliability of the supplied energy is also calculated. Furthermore, the protection of the power line is designed and the correctness of its setting is then verified on the model in the PSS Sincal software.
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Design of the expansion of 22kV distribution network in a specific area
Řehoř, Jiří ; Beneš, Jan (referee) ; Blažek, Vladimír (advisor)
The aim of this work is the reconstruction and development of the distribution network of DS to ensure electricity supply in the required quality to existing customers and new customers connecting to the planned industrial zone Šlapanice. The first part deals with the inclusion of a distribution network in power system, its distribution and composition. Subsequently, the work deals with the description of the management of distribution networks, cable and outdoor leadership and their parameters. It also contains guidelines for the design of high voltage networks. The end of the first part is devoted to calculating the steady operation of the network. In the second part, the proposed project using the PAS DAISY Off-line v 4.00 Bizon. Based on the available evidence is developed steady state operation. We found that lines are overloaded and need to be strengthened with regard to the development of industrial zones and adjusting the network to ensure safe and reliable operation. The conclusion focuses on the economic evaluation of proposed alternatives.
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Monitoring in Middle- and Low-Voltage distribution systems penetrated by distributed generation
Kolacia, Tomáš ; Kolář, Vladimír (referee) ; Drápela, Jiří (advisor)
This thesis concerns monitoring in Middle- and Low-Voltage distribution systems penetrated by distributed generation. Monitoring itself means measuring voltages and power flows and sending relevant data to the supervisory system. The first part of the thesis describes distribution systems with differences between individual voltage levels. The following chapter is focused on consequences of high share of renewable energy sources in distribution systems. Most of the problems are partially resolved by technical conditions for connection of the new power sources. However, difficulties with voltage regulation and uncontrolled power flows to higher voltage levels remain. These are the reasons for measuring voltages and currents in medium voltage networks. Second to last subhead of this chapter is dedicated to possible benefits of monitoring. The fourth part of the thesis deals with voltage and current sensors with their advantages and disadvantages. The best suitable devices are chosen in the end of the chapter. It is crucial to mention that sensors are only part of measuring system. Analog outputs from current or voltage transformers need to be converted to digital signal and further processed. After that required quantities are finally sent. Properties of these circuit cards are described in the sixth chapter. Following part aims to define a certain key that will determine the suitable locations for installation of the measurement. The final part of the thesis compares measured voltages and power flows from real 22 kV network with calculated values from computer program PAS DAISY Bizon.
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