This thesis deals with the steady operation and short-circuit conditions in the 110 kV network E.ON in a separate and parallel operation of nodal areas of Otrokovice substation and Sokolnice substation. The theoretical part is devoted to the calculation of steady state high-voltage systems using Newton's iterative method, transient phenomena that may occur in the power system short-circuit calculations and theories. The practical part deals with the actual calculations of steady state and short-circuit conditions in a separate and parallel operation of nodal areas Sokolnice-Otrokovice, which were calculated using the dispatching program. These calculations are then evaluated for possible use of involvement in actual operation. At the end there are suggestions on operational measures in the network 110 kV.

This work describes an actual condition of a specific part of a distribution power grid. It is a research of problems based on the computer model in case some power line is in failure or shut down. Simulations are calculated for both currently used load and load expected in future usage. There are partial solutions depicted for each issue found during the simulation. Some of those are used for a final design of a distribution power grid. In the last section, there is a comparison of different types of power lines and their possible usage in the design.

This diploma thesis deals with the technical design of extensive replacement of overhead lines by high voltage cables in the given distribution area. In its first part the thesis is focused on the survey of the concerning legislation and technical standards, which must be followed during making technical design documentation. It also mentions the processes which precede the replacement itself. There are also the operational differences between the overhead lines and the high voltage cables in the first part, too. The second part is focused on the technical description of the given area, the technical design of the replacement by high voltage cables and the realization of calculation, which is important as a base for further realization of technical arrangements. The consideration of technical feasibility and economic efficiency are also contained in the second part.

Master’s thesis deals with computation of steady state and short-circuit conditions in 110 kV nodal area of Čebín. The first part of thesis is theoretical. There is described computation of steady state and short-circuit conditions. There is description of 110 kV nodal area of Čebín too. There are made computations in the practical part. Two types of operation of transformers T401 and T402 are evaluated. The transformers operate independent at first, then they are connected in parallel. Voltage conditions in substations, load of lines and transformers, power losses and short-circuit resistance of substations in 110 kV nodal area of Čebín are evaluated based on the computations. There are compared the both types of operation of transformers in the end of practical part.

Diplomová práce se zabývá metodou hybridních (hranových a uzlových) konečných prvků ve frekvenční i časové oblasti. Tato metoda je použita pro analýzu vlnovodu parallel-plate, v kterém jsou umístěny dvě dielektrické vrstvy. Jako ukončení vlnovodu je implementována dokonale přizpůsobená vrstva označována PML. Projekt řeší možný výběr PML vrstvy v časové oblasti. Metoda je programována v programu MATLAB a výsledky jsou porovnány s programem COMSOL Multiphysics.

In the distribution network 110 kV of E.ON Company there are the nodal areas of Čebin substation and Sokolnice substation which are operated separately at the present time. There is one 400/110 kV transformer for each nodal area. In case of fault on one of these transformers or on busbar in which the set transformer is working, it comes to an outage of electric supply in the set nodal area. This problem has to be solved with help of the parallel operation of nodal areas of Čebín substation and Sokolnice substation. The main and also the practical task of this work is to design the bridge connection appropriate for parallel operation of nodal areas (supply transformers 400/110 kV). With help of a computing program there were made calculations of steady state and short-circuit conditions in distribution network 110 kV for separated and parallel operation of nodal areas. Voltage conditions, load of transformers (400/110 kV and 110/vn kV) and conditions on 110 kV lines are evaluated and controlled as the result of steady state calculations. Based on short-circuit conditions there is controlled the short-circuit resistance of the substations. Finally there are compared advantages and disadvantages of separated and parallel operations of nodal areas. If necessary, technical arrangements required for introduction of parallel operation of nodal areas of Čebín substation and Sokolnice substation will be designed. The theoretical part of the work deals with calculation of steady state with help of iterative methods, namely Newton´s and Gauss-Seidel methods. There are further described the method of calculating short-circuit currents, characteristic values and time behaviours of short-circuit current.

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.