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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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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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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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Stabilized operation and short - circuit conditions within E.ON 110 kV power network supplied from Čebín 110kV switching station, during the period of 2011
Chrástek, Radim ; Janda, Petr (referee) ; Blažek, Vladimír (advisor)
The aim of this thesis is to project an operation of bridge connection in distribution network in Čebín’s nodal area. The main task is to check a fulfilment of voltage tolerance in distribution substations 110 kV, load transformer control (400/110 kV, 110/VN kV), distribution power line 110 kV control and short - circuit conditions control. Relevant calculations are performed by dispatching control system, which works with the actual parameters of all distribution network‘s 110 kV facilities. The theoretical part of this thesis is devoted to the way of the calculation of stabilized operation and the short-circuit conditions. In practical part, first we perform an analyse of stabilized operation and the short-circuit conditions of distribution network 110 kV in actual operation. Next step deals with bridge connection design and analysing its operation. The operation of bridge connection is verificated even in specific conditions (disturbance state, increased load). The next section evaluates the results of the calculations. First we deal with actual operations evaluation and proposed the bridge connection. In the next section we evaluate the operation of the bridge connection in the specific operating conditions. Finally, we evaluate the losses in the distribution network 110 kV. If the calculations of the stabilized operation or the short-circuit conditions of distribution network discovers that some of its elements are overloaded, we propose changes to ensure safe and reliable operation of the distribution network.
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Short Circuit Calculation of MV Grid
Knápková, Dagmar ; Topolánek, David (referee) ; Toman, Petr (advisor)
This bachelor’s thesis deals with the faults in the distribution networks, focusing on shortcircuits as the most common and the most signiĄcant types of faults. The thesis is divided into theoretical and practical part. In the theoretical introduction, describes the types of faults in distribution networks with a focus on the short-circiuts, their causes, and the impact on distribution networks. Follows a description of the time course of short-circuit currents, short-circuit calculation simpliĄcation assumptions, the formula for calculating the impedance of the various elements of the short-circuits schema and the calculation methods of short-circuit currents in accordance with ČSN EN 60909-0. In the practical part, there is an example of the calculation of simple network conĄguration. Follows an analysis of the real network, including the analysis of the method of operation and the selection of appropriate method for the calculation of the short-circuit. After that are carried out practical calculations short-circuit conditions in four places on the network, and three diferent types of short circuits. For one-phase short-circuit is subsequently carried out the distribution of currents in a parallel branch of the distribution lines. At the conclusion of the bachelor’s thesis is caried out evaluation the results and analysis of the data obtained by calculation.
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Load Flow Calculation and Design of Distance Protection Relay Settings of 110 kV Overhead Line
Jasenský, Filip ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Bachelor thesis load flow calculation and design of distance protection relay settings of 110 kV overhead line acquaints with the theory calculation of steady operation, short-circuit conditions and a proposal setting the distance protection. The theoretical part is made an example of a simple calculation to show leadership methods of calculation. The practical part is a calculation of steady operation and short-circuit conditions. Short-circuit ratios are calculated for a single operation and parallel operation of transformers in Otrokovice. Calculated using the initial shock symmetrical output from the calculation of short-circuit conditions is verified by short circuit resistance of substations. The practical section setting the distance protection ABB REL 316*4 and compensation earth faults. Calculation of steady state and short-circuit conditions designed basic operational state of the network, for which the design of a distance protection relay settings.
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The analysis of parallel operation variants of supply areas 110 kV Čebín and Sokolnice
Reiter, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
The diploma thesis is focused on the analysis of parallel operation of Čebín and Sokolnice substations. Different variants of parallel operation are researched. A calculation of steady state by the iterative method is described in the theoretical part. The next part briefly mentions a short-circuit and dimensioning of conductors. The possibility of overloading of lines and transformers is discussed in the last chapter of the theoretical part. The current state of the situation is described in the practical part. Main goal of the practical part of the diploma thesis is to design a configuration capable to parallel operation. Also another configuration of supply of this area is designed. There must be no direct connection between Čebín and Sokolnice substations on 110kV level in this configuration. This configuration should eliminate a transit flow of power. Each configuration has to fulfill the requirements on the steady state and on short-circuit current capability. One of the last chapters is focused on the steps, that should by undertaken to prevent transit flow of power.
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