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Sensitivity analysis of costs on power outages resulting from nonadherence of custom - tailored standards of the continuity of power supply
Polák, Jiří ; Skala, Petr (referee) ; Blažek, Vladimír (advisor)
The goal of the thesis is to describe the approaches used for the regulation of the continuous supply of electric power in the selected countries of European Union and to determine the power outages costs in the specific distribution network, resulting from non-observance of the customer standards used in Great Britain, Sweden and Finland. The costs have been calculated for the entire network, as well as for the individual outputs. The thesis carries out the sensitivity analysis of the power outages costs, resulting from the breaching the supply restoration standards and the multiple interruptions standard used in the Great Britain. The costs of the individual limits are shown in the tables and the graphs. The comparison of the individual outputs according to the height of the penalty costs have been carried out on the selected set of limits. The comparison of the order of the individual outputs is then carried out for the customer standards used in Great Britain, Sweden and Finland.
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Conceptual design of the reconstruction of an E.ON 22 kV distribution network installed at a specic area
Vepřek, Tomáš ; Nepevná, Vlastimila (referee) ; Blažek, Vladimír (advisor)
The aim of this thesis is a modification of the distribution network (DS) of the city of Brno to ensure power supply in the required quantity and quality for end consumers. Calculation of steady - state operation of distribution network (DS) of Brno is performed in the programme PAS DAISY Off-Line v.4.00 Bison. On the basis of available data (dispatching scheme, load current of stem lines and reserved power of wholesale customers) we will analyze the steady-state of network. We will find out which of the 110/22 kV transformer stations, cable and overhead lines are overloaded and perform network adjustments to ensure safe and reliable operation by 2015. We will identify in which year we will need to build a new power node in the northern part of Brno. The conclusion is focused on technical and economic evaluation of proposed alternative network arrangements.
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Change of voltage at LV terminals of a MV/LV power distribution transformer caused by changes in its load
Jandora, Jiří ; Bátora, Branislav (referee) ; Blažek, Vladimír (advisor)
The thesis deals with the use of distribution transformers, their integration into the electrical network, their properties, and principles and means of regulation according to changes in load. The introductory chapter is devoted mainly to the theoretical background concerning the functioning of the transformers. Even though it is not the focus of this thesis, a brief summary of their structure will be provided because it is presumed that not all the readers are familiar with this particular electrical network block and thus they should be explained how the transformer works. Then the ways of transformer regulation will be outlined. In the theoretical part, the important point for the reader is the substitution of the transformer by two-port network i.e. the equivalent circuit. The two-port network is a substitution of the connection properties by simple electric elements, which are not so problematic for further use. When dealing with the two-port networks in the chosen equivalent circuit, Blondel’s constants will be used. Blondel’s constants facilitate working with the basic network invariables of the circuit such as amperage, voltage and power. The second part of the thesis is devoted to solving a problem that involves the use of distribution transformers. The problem is as follows: there is a manufacturing plant with three transformers, each of them having rated power and nominal transformation ratio. The manufacturing plant is supplied by HV three-phase line with rated voltage and parameters given by the distribution point, where constant voltage is maintained. The task is to determine in what ways the voltage of the low voltage terminals of the transformers will change when changing the power from idling circuit to the rated load. The power factor should be constant. The method for solving this task has already been outlined in the theoretical part. The results are summed up in a simple chart completed with diagrams, which concisely describe the result of the research.
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Steady state and short-circuit conditions within E.ON 110kV power network at bridge operation of transformers T401 and T402 in 400/100kV transformer station Čebín
Klobučník, Jozef ; Janda, Petr (referee) ; Blažek, Vladimír (advisor)
Master’s thesis deals with computation of steady state and short-circuit conditions in the 110 kV distribution network in the nodal area of Čebín. Computations are done during independent operation and bridge operation of transformers T401, T402 in transformation station Čebín with proposed configuration of network. Additional computations of steady state during specific operating conditions such as (T401 outage, disconnection of line 5553) were done during network operation in bridge operation of T401, T402. Voltage conditions in substations, load of 110kV lines and 400/110 kV, 110/HV kV transformers are evaluated based on the computations of steady state. Short-circuit resistance of substations is being evaluated with the aid of calculations of short-circuit conditions. There is a comparison and processed results of computations during independent operation, bridge operation, special operational states and proposed technical measures of operation in bridge operation in the end of the thesis. Theoretical part of the master’s thesis deals with the description of 110 kV distribution networks, theory of calculation of the steady state of electric system with the aid of Newton iterative method a calculation of single-phase and three-phase short-circuit current with the aid of method of symmetrical components.
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Stabilized operation of the 400 kV power line
Jurča, Ondřej ; Bok, Jaromír (referee) ; Blažek, Vladimír (advisor)
This thesis deals with methods of solving lines under voltage levels of a very high transmission voltage and extra high voltage. The first, theoretical part of this paper analyses different methods how such lines are solved. In particular, an accurate solution is provided simulated by means of a line with evenly distributed parameters, and an approximate solution simulated by means of a line with lumped parameters. Furthermore, special cases of steady running conditions of the line are reviewed, such as no-load running, short-circuit run and line operation with natural load. In conclusion of the theoretical part is given a general method of solving an extra-high-tension and extra high voltage network; also, some graphical methods of solving such networks are shown including their brief description. The second, practical part of the present paper involves application of the above mentioned methods of solution on a specific line with given parameters, solving conditions at the beginning of the line under steady running conditions and in special cases of the line operation. The conclusion of the thesis summarises the obtained results and provides final assessment of the individual methods of solution in terms of calculation accuracy.
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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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Steady-state operation of 110 kV power line
Pastorek, Jaroslav ; Bok, Jaromír (referee) ; Blažek, Vladimír (advisor)
This Bachelor's thesis addresses the steady operation of 110 kV power lines. It is well known that these lines are used within the distribution system of very high voltage levels and are used to transfer large amounts of energy over long distances. The essential prerequisite for the transfer of such an amount of energy is to achieve the greatest efficiency possible. Therefore, there are methods developed, by which under known circumstances on one end of the line we can calculate the line ratios at the other end. These methods can be classified into exact, approximate and graphic methods. With approximate methods, T – element and ? – element, the most popular ones, are used. Only a brief description of the graphic method is given. Before the calculations of these methods, a procedure for determining various parameters of the external line is described. In the practical part, calculations based on the given example are listed. The example addresses calculation of ratios at the start of the line and ratios during short-circuit and freewheeling operation. The end contains a brief summary and comparison of the results. 100 kV lines can be either designed either as buried cables or external lines hanging from pylons. Buried cables are rarely used for 100 kV, so this Bachelor's thesis is focused on external lines.
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Steady state and short-circuit conditions in 110kV E.ON network fed from Sokolnice transformer station
Vyčítal, Václav ; Rampl, Martin (referee) ; Blažek, Vladimír (advisor)
This thesis can be divided into five main parts. The first part deals with theoretical analysis of power flow calculation in power network during steady state condition. Load flow calculation is presented here as a linear and nonlinear problem. Newton iteration method is proposed for solving power flow as nonlinear problem. The second part of this thesis deals with the analysis of short-circuit calculation in accordance with valid International Standard IEC 60909. The equivalent voltage source method is adopted in case of the short-circuit calculation. For the calculation of unbalanced short-circuit currents, the symmetrical components method is also presented. The last three parts of this paper are focused on calculations of power flow and short-circuit conditions in power grid Sokolnice. So in the third part is the description of nodal area Sokolnice with its substations and the calculation of load flow and short-circuit conditions for two different power supply options. For each supply option is also considered an abnormal (fault) grid condition. (overall there are solved four different options) The fourth part of this thesis deals with the result analysis and also the results of different power supply options are compared. In the last part there are presented necessary technical improvements for fault-free operation of power grid Sokolnice based on the result of power flow and short-circuit conditions in that grid.
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Short Circuit Currents in the Sokolnice 400 kV Switching Station with Direct 400/110 kV Transformation Applied
Vojtěch, Pavel ; Špaček, Jaroslav (referee) ; Blažek, Vladimír (advisor)
The destination of this Bachelor´s Thesis is to explore short circuit currents for voltage level 400 kV in the switching station Sokolnice before year 1995 and after this year, when came to installation of the convertor T402 and to voltage direct 400/110 kV transformation applied. The Thesis is detecting at relation as for three-phase short circuit do for single-phase short circuits, for 400/220/110 kV primary transformation variation in voltage and for variation 400/110 kV, the change which came after connection of the convertor T402. In base of this calculation will be explored the short circuit resistance rating switching station in agreement with parameters ordered by the comp. Inc. ČEZ Prague.
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