Auswahl der wissenschaftlichen Literatur zum Thema „Paralelní chod“

This works applies the idea of adjustment an engine-generator, so it is possible to connect an engine-generator, or other type of a generator, to the electricity. Consequently, the machine can transform the power supply without an outage. This work concerns the complex approach, provides the descriptions of particular parts, sensors and active components of a motor-generator and includes the explanation of their function. Further research is focused on designing and drawing a plan with a choice of a control unit for the whole system. Finally, the work deals with the complex implementation and testing the machine in real operation.

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 master’s thesis is divided into two logical parts. The first part contains theory of calculation of steady state and short-circuits conditions within 110 kV distribution network. Newton’s method and short-circuit current calculation is also explained here. It also deals with classification and aftereffects of transient performance occurring in power networks. The second part contains practical calculation of steady flow and short-circuit conditions at parallel operation of transformers T403 and T402 in 400/110 kV transformer stations Sokolnice and Otrokovice. This calculation is done with program used by system operators called SINAUT Spectrum and consequently analyzed. This part also contains brief description of substations from this region.

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.

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.

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.