|
|
Design and optimization of laboratory HV models
Kočí, Zbyněk ; Vyčítal, Václav (referee) ; Varmuža, Jan (advisor)
Bachelor's thesis is focuses on the operation of the distribution system in the Czech Republic and the use of new types of cables in the world. It describes the characteristics, division and use of overhead lines and cable lines. This work also deals the division and control DC networks, their advantages and disadvantages. In superconducting cables is engaged in their development, advantages and disadvantages. Describes their application and use in the future. It also describes the parameters affecting the properties of the ropes and the cables of the AC and DC wiring and ways to mitigate the negative effects on the ropes and on the surrounding environment. Work deals with measurement and counting of the laboratory models for their optimization. Finally, the work describes a proposal of new laboratory model for the measurement and stating components, which are needed for optimization models and the production of a new model
|
|
|
Unsymmetrical power flow calculation with the help of software applications
Ermolenko, Ilya ; Koudelka, Jan (referee) ; Vyčítal, Václav (advisor)
This work consists of four parts. The first part of the thesis provides a theoretical introduction to the power flow calculation problem. Furthermore, the analysis of power flow calculation as a linear and as a nonlinear problem is performed. In this thesis, Newton’s iteration method is used in the calculation of the nonlinear problem. The following describes possibilities for improving the power flow calculation by improving the Newton's iteration method and using non-standard methods. The second part describes the possibilities of power flow calculation using various software applications, such as Pandapower, Matpower, OpenDSS and PSS Sincal. In the third part of the thesis the selected software applications tool is used to test the possibility of unsymmetrical power flow calculation in the LV network for the state with and without the PEN conductor, and the calculation of the ground fault in the compensated network. In the fourth part of the work, the unsymmetrical power flow calculation is tested for a larger LV network, further is performed the evaluation of the influence of PEN conductor modeling on the calculation results compared to the calculations of a network without this conductor.
|
|
|
Measurement of electrical soil resistivity
Matyska, Stanislav ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
This master’s thesis deals with the measurement of the electrical soil resistivity. In the theoretical part there are described the methods by which the soil resistivity is measured – especially the Wenner’s method, which was used for the practical measurements. Then there is also described the one-layered and the two-layered model of this method. Furthermore, there is described the procedure for the measurement of soil resistivity using the OMICRON CPC 100 and PU 193 instruments used in the measurement. To verify the modeling of a two-layered soil model, the theoretical part of the thesis describes the soil modeling process using the program Ansys. As for the practical part of the thesis, the measurements were carried out in three localities: Brno – Královo Pole; Hrušovany nad Jevišovkou – Pravice; Hustopeče nad Bečvou – Vysoká. The measured values were processed using the Matlab’s graphical user interface (GUI) that was developed within this thesis. From these values, at least one two-layered soil model was created for each location and both meters – a total of 12 models were created. For these models, measurements were simulated in Ansys. The results of the simulations were then compared with the measured values. The aim of this thesis is to compare the measured data with the data obtained by the simulations and subsequently to describe the suitability / unsuitability of the substitution of the one-layered soil model for the two-layered one for given measurements.
|
|
| |
|
|
Touch voltages and earth surface potentials of selected earthing systems designs
Novodomec, Radim ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
The aim of the bachelor’s thesis was to investigate the influence of the shape, size, placement of earthing systems designes as well as the influence of the soil model on the size of the resulting potential and touch voltage during the passage of ground current. For the construction and subsuquent simulation of these phenomena, the Ansys Maxwell Desktop program was used, which is suitable for using the finite element method, as the use of analytical methods is demanding. The results were further processed in Excel into graphs. The resulting touch voltage was determined as the difference between the maximum potential of the earthing system and the potential at distance of 1 meter.
|
|
|
Magnetic field measurement with gaussmeter FW BELL 4090
Urbánek, Pavel ; Krčál, Vít (referee) ; Vyčítal, Václav (advisor)
This thesis focuses on the basics of magnetic field and its measurement. The field will be measured with the FW Bell 4090 instrument and depending on the success and accuracy of the measurements, the bachelor thesis should include a possible integration into teaching. The measurement of the magnetic field will be adjusted to verify whether the device parameters in accordance to the manual. The most important attributes are the accuracy of single field or multi-field measurements, the accuracy of measurements in all axes of the instrument, and measurements over a given frequency range.
|
|
|
Conventional energy sytems in numbers
Mičánek, Jiří ; Paar, Martin (referee) ; Vyčítal, Václav (advisor)
Tato práce hodnotí možné budoucí energetické mixy pro Českou republiku. Uvádí údaje týkající se jednotlivých dostupných energetických zdrojů se zaměřením na výrobu elektřiny. Emise skleníkových plynů a další relevantní parametry jsou váženy a použity k hodnocení různých návrhů pomocí Pughovy matice, která umožňuje objektivně kvantifikovat scénáře. Pro zjištění názorů veřejnosti a ověření, zda se údaje dostupné prostřednictvím výzkumu shodují s jejími názory, je použit průzkum. Metodiky použité k hodnocení scénářů jsou podrobeny kritice a jsou uvedena doporučení, které z nich by měly být vyřazeny a jak zlepšit opakovanou analýzu.
|
|
|
Impact of cross-country double earth faults on voltage condition in LV networks
Fojtášek, Jan ; Vyčítal, Václav (referee) ; Topolánek, David (advisor)
This master's thesis is focused on the influence of double earth fault on voltage ratios in the compensated network. This thesis is focuses on, in particular on the analysis of voltage ratios on the secondary sides of distribution transformers when this non-local fault occurs. The compensation of the non-local double earth fault using the symmetrical components method is performed and the performance of this method is verified. The analysis of the effect of double earth fault on the proposed power system is carried out in PSCAD software and further evaluated. This type of non-local fault is investigated while modifying the various parameters of the designed system. To differentiate the double earth fault from the two phase ground fault, the asymmetry on the LV sides of the distribution transformers is investigated. A locator is provided to locate the location of the double earth fault and the two-phase ground fault, which, combined with the asymmetry values, is able to determine both the location of the fault and the differentiation of the co-located fault from the non-co-located fault.
|
|
| |
|
|
Simulation of earthing system resistance measurement
Pirochta, Josef ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
In this bachelor thesis, the effect of different soil models and random wire placed underground on the results of earth resistance measurements using the 4-pole method was investigated. To determine this influence, simulations were performed in Ansys Electronics software, in which different soil models (with local inhomogeneity, horizontally divided soil and soil divided at an angle) were created. In these models, the measured earth was placed together with the measured random wire and its resistance was determined by simulating the measurements and with respect to the distant ground. The effect of the different soil models on the accuracy of the measurements was determined from the differences in the resistance of the earth random wire obtained by measurement and with respect to the distant ground. It was found by simulations that, of all the variants investigated, performing measurements in the presence of different soil models and a random wire can lead to a measurement error of up to 7,2 %.
|
guest ::
RSS feed.