|
|
Steady state calculation of 22kV network
Kaplanová, Klára ; Opat, Jaroslav (referee) ; Topolánek, David (advisor)
Master's thesis proposes a new operation state of distribution network 22kV in Prostějov district after connection of the new Prostějov – Západ substation. The PASS DAISY OFF-LINE Bizon program is used to calculate power losses, optimal network possibilities, as well as to create a new model of Prostějov district's distribution network and to design a modification of a current state of given location. A description of this calculating and simulation program is also included in this paper. The theoretical part describes calculating methods of distribution network’s condition, with emphasis on mathematical method used by PASS DAISY OFF-LINE Bizon program, the modified Newton-Raphson method. The aim of this paper is to prepare technical documentation for E.ON company, with respect to new operation disconnection, planned overhead and cable lines of corresponding parameters. These changes in network's configuration will cause a new distribution of feeding areas. As a result, related changes of provided power from individual feeding points and changes of power currents in electric lines will occur. Due to new operation connection, a reduction of losses and, simultaneously, an improvement of voltage ratios are expected. One of the aims of this paper is to update network's model in PASS DAISY OFF-LINE Bizon program to match the current network’s state of a given area. The outcome of this work is a comparison between the current condition and the new operation condition, with new Prostějov – Západ substation connected, from perspective of distribution network's operator.
|
|
|
Distribution of short circuit currents and voltages in unsymmetrical faults
Kakrda, Michal ; Topolánek, David (referee) ; Haluzík, Evžen (advisor)
The objective of this bachelor thesis is to introduce the calculation of voltage and current ratios in asymmetrical short circuits. The first part of the thesis is focused on delineating the problem of short circuits in general. It describes the causes of short circuit arising, the types of short circuits and their processes. The next part of the thesis shows the ways of calculating particular types of short circuits, namely concentrating on the method of symmetrical components. The last part of the thesis is focused on the application of the discovered findings to calculate the ratios for the particular electric network. The calculation has been made for all the types of short circuits, both symmetrical and asymmetrical. The resulting ratios are recorded into the phasor diagrams for particular types of short circuits. The part of the calculation is also the recalculation of phase currents through a transformer.
|
|
|
Testing of the admitance principle of the fault indicator
Musil, Milan ; Vyčítal, Václav (referee) ; Topolánek, David (advisor)
The thesis deals with the proposal, implementation and evaluation of test for fault condition indicators. Thesis focusing on earth fault indicators based on admittance principles. These indicators must be able to evaluate earth faults in compensated, compensated with auxiliary resistor, unearthed and high-resistance earthed networks. The proposed tests verify the current and voltage measurement errors in inputs including monitored characteristic variables such as conductance and susceptance. The proposed test are applied to a selected ample of the fault indicator. As part of the tests, the indicator is subjected to secondary test using the Omicron CMC256plus tester as well as test on fault records that have been converted to COMTRADE for this purpose. The last series of tests carried out uses the physical model of the medium voltage system, where the tested equipment is subjected to fault states in the compensated whit auxiliary resistor system and isolated system. Furthermore, part of the thesis is research of new methods of earth fault detection, including their principles and function description. Also included in the thesis is an overview of manufacturers of indicators, or protection, who are involved in the production of earth fault protection.
|
|
|
Current Transformers and Current Sensors Confrontation
Popek, Jiří ; Bok, Jaromír (referee) ; Topolánek, David (advisor)
Current transformers and current sensors are devices which are mostly used for current measurement in high voltage systems. This devices transform measured currents to range which are workable for measurement and protection devices. Current transformers have been using for current measurement since electric system was built. Current sensors are using for measurement after applying digital devices in their secondary circuits. Theoretical part includes fourth and fifth chapter. These chapters contain construction analysis and characteristic points for both devices. Practical part is in chapter six. This chapter consists results from laboratory measurement. Results are used for verification with theoretical part of the thesis. Accuracy class in nominal range and progress for measurement error in overcurrent range was verified for tested devices. Conclusion of this thesis comparing properties and summarises results from laboratory measurement.
|
|
|
Generating of the fault record for protection and fault indicator testing
Bažata, Petr ; Jinderle, Pavel (referee) ; Topolánek, David (advisor)
The thesis is focused on a presentation of a model creating which is followed by the simulation of running real network with using the compensatory elements to minimize the incurred failures. This thesis is divided into two thematic parts – the first theoretical one deals with the basis structuring of short-circuit faults and more detailed study of ineffective ground connection. Particularly this part attends to the problematic of a network description with extinguishing suppression. Using the compensation minimizes the impact of the failure state. A short-term fixing of a resistor improves the function of the ground-fault protection and helps to detect the outgoing section damaged by the defect. Furthermore the thesis indicates simulation programs, compares them and chooses the most suitable one for the next practical part. This is focused on a simulation of a real network run, together with elements for an effective defect-reduction or easier detection of ground connection. As a simulation of a ground short-circuit is the model in the end of the thesis modified on a network with an effective grounded bundle. Testing of the model correctness and creating a record of a model using the real ground protection settings is also one part of this thesis.
|
|
|
Verification and testing of the experimental model of 22 kV distribution system
Hlaváč, Jan ; Novotný, Jan (referee) ; Topolánek, David (advisor)
This bachelor’s thesis deals with the practical verification of the various elements of the model of 22 kV distribution system. This model was designed within the laboratory space to remind of the most realistic distribution system. User of the model can (besides the normal operating conditions) perform a simulation of a fault condition. The aim of the work is to create guidelines for measuring key parameters of the system components (transformers, power lines), to compare the designed a measured values and to create the complete assembly documentation. This documentation serves as a guide with the detailed description of each component. The final part of the work is to create a complete schematic diagram of the power substation and the selection of the suitable protective devices.
|
|
|
Design of supply network configuration for large engineering company
Němec, Jan ; Holoubek, Jiří (referee) ; Topolánek, David (advisor)
This master-thesis analyzes issues of suggestion configuration of power supply network of industrial business. The option of the scheme of the configuration, the voltage level, the way of compensation of the reactive power, the way of the suppretion of the energetic interference and other requirements is included in the main tasks. This option has to be convenient with the requirements of the industrial business. The important point of this proposal is to prevent the influence of the superordinate distribution network. The compensation which keeps the power factor in the prescribed limits is one of the precautions against the influencing of the network. The second precaution is the elimination of energetic interference. The higher voltage, the fluctuation and the asymmetry of the voltage are the interferences which have the biggest impact on the industrial networks. The master-thesis offers the summary of the possibilities and ways of the elimination of the basic elements of the energetic interference.
|
|
|
Evaluation of nonstandard operation possibilities of power sources in MV network
Čáslava, Jiří ; Opat, Jaroslav (referee) ; Topolánek, David (advisor)
This Master's thesis deals with solution of nonstandard operation connection of E.ON's 22kV distribution network in given area, considering the possibilities of operating dispersed electric power sources currently available, as well as possible power sources connected to the distribution network in the future and its potential operation limitation. A part of this paper is a description of calculation methods used for network evaluation in steady state, with emphasis on linear calculations used by E-Vlivy program, in which the operational possibilities are simulated. Therefore, a description of this program is also included. Suggested operation possibilities correspond with E.ON's valid distribution network operation rules. The outcome of this paper will serve to E.ON's 22kV network's controllers as materials for network operating in nonstandard operation states.
|
|
|
Distribution Network Development and Configuration
Pospíšil, Petr ; Beneš, Jan (referee) ; Topolánek, David (advisor)
The theme of this master‘s thesis is distribution network development and configuration in the part of Brno – Trnitá. There is expected to be investments there in the next few years. The thesis consists of two parts. For better understanding of this problem, the first theoretical part concerns with the description of electrical network (subdivision in accordance with voltage levels, conductor types, network types and other electrical network parts), solution of grid’s steady state (as a linear task and also non-linear task, elimination of the balancing node, the iterative method) and Brno distribution network characteristics. The second part concerns with distribution network development and configuration depending on anticipated load development in Trnitá. The result is proposal for transformer station construction Opuštěná fitted with three transformers of nominal output SN = 40 MVA and network configuration change required both for providing new consumption supply as well as sustaining current one.
|
|
|
Earth Faults Protections
Ostruška, Jan ; Topolánek, David (referee) ; Orságová, Jaroslava (advisor)
The thesis deals with wattmetric and conductance principle of faulted feeder detection in medium voltage compensated distribution networks. These principles are analysed and tested with particular emphasis on high impedance earth faults. The first part of testing utilizes data about state of the system with earth fault, which was determined by designed static model of earth fault. The testing in the second part utilizes real records of high impedance earth faults. In both parts the wattmetric and conductance protections was presented on protective relays ABB REF 615, ABB REM 543 and Protection&Consulting RYo by means of unit OMICRON CMC 256plus. As a major result of performed tests are records of detection of particular earth faults. Based on these records it could be concluded, that functionality of protections is substantially dependent on magnitude of zero sequence voltage. Furthermore the wattmetric protections are dependent on fault resistance as well.
|
guest ::
