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Modern protection of distributed energy resources
Bučko, Ondrej ; Kopička, Marek (referee) ; Topolánek, David (advisor)
The aim of this thesis is to describe distributed energy resources (DER) protection system’s main problems and to suggests their possible solutions. The second part is focused on collecting information and description of the new functional principles of protection devices used for protecting distribution network against backwards influences from the DER. The purpose of the thesis is the description of functional principles of the protection devices that are not commonly used in the distribution networks of the Czech Republic. In addition, the schemes of functional blocks of the protection devices that help to configure or project them are also part of this thesis.
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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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Evaluation of MV/LV network earthing systems
Sítař, Martin ; Topolánek, David (referee) ; Kopička, Marek (advisor)
This master's thesis deals with the measurement of grounding systems in HV/LV distribution networks, which includes grounding system of distribution substation and transmission lines. Explores the issue and principles for the measurement of parameters, which are important for the protection of persons and animals in order not to touch exposed conductive part accidentally, protection of electrical machines and equipment against high fault current and dangerous surges while the correct function of the connected electrical equipment is maintained. These parameters include earth potential rise, ground resistance, soil resistivity, touch voltage, step voltage and transferred potential to the LV network. The aim of this work is the preparation, analysis and subsequent evaluation for the real measurement in practice. These earthing-system measurements were carried out at the distribution station and the concrete pole with a section disconnector. Then a numerical model of the grounding system of concrete pole was created in ANSYS. Subsequent evaluation of the results as numerical terms (comparison measurements and simulated results) and evaluation in terms of analytical (measurement results compliance with the standard) including the numerical model of the earthing system is solved in the practical part of the master's thesis.
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Options of network operation with distributed generation sources in island operation
Mareček, Tomáš ; Drápela, Jiří (referee) ; Kopička, Marek (advisor)
This diploma thesis presents managing of the island mode using distributed generation. In the theoretical part of the thesis, the power system of the Czech Republic is described, together with its future development, and future development of installed capacity of distributed generation. Types of distributed generation are also mentioned. Next part of this work is focused on technological parts of islanding operation and its requirements. The following part describes components of the smart grids and mentions some of its functionalities. The practical part of the thesis describes the created models of components in PSCAD programme. From those components two slightly different grid models are created. On those grid models, simulations are made, during which island mode is created. Some of the grid functionalities are tested during those simulations, for example; reaction of the island mode for load increase, load decrease and others.
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HV grid model in PSCAD
Tomšů, Vojtěch ; Ptáček, Michal (referee) ; Kopička, Marek (advisor)
This thesis deals with the issue of computer modelling and electroenergetic calculations. The first part focuses on the description of the PSCAD program and selected competitive software. There are listed main characteristics, usage and subsequently the overall comparison of the programs with potential use in electroenergetic industry. It also lists the basics of PSCAD and description of its working environment. Another section deals with the calculation of parameters of overhead lines, transmision lines substitute with pi-section and the process of pi-section phasor diagram construction. In the next part, there is a model of HV grid in the form of pi-section. As reference values for simulation were used values from exercise of the subject Distribution of electric energy. Output values obtained from the simulation in PSCAD were used to create a phasor diagram in Matlab. The last part focuses on the issue of calculating the natural power, cascade and parallel sections sorting and a simple case of three-phase fault.
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Model of Stirling Engine in PSCAD
Gallo, Michal ; Kopička, Marek (referee) ; Radil, Lukáš (advisor)
This dissertation about the Stirling engine deals with the history and formation of the heat engine. At the beginning of this work, fundamental parts and their functions are described, elucidating the principle of operation explained by the thermodynamic cycle and subsequently comparing the ideal and the real Stirling cycle and last but not least provides various modifications whilst describing their differences. The mathematical model of the Stirling engine is processed by Schmidth’s theoretical analysis and thereafter is created in PScad v46. The process of creating a model is shown in one of the chapters of this dissertation. The results were taken into account in the design of 3D models in Inventor Professional by Autodesk. The work concludes with the evaluation of the computational model and its functionality as well as the documentation of the 3D model.
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Voltage profile regulation in Low-Voltage distribution systems
Koštialik, Marek ; Kopička, Marek (referee) ; Drápela, Jiří (advisor)
This paper deals with controlling the voltage profile in low voltage distribution networks. In the first part of the theoretical analysis is the solution view of inadequate elimination connecting renewable energy sources on distribution network. Subsequently, in a published review of factors representing the power quality in LV. The second part is a detailed search of the individual voltage regulators in consideration their specific solvability in LV. In the practical part will followed by the selection and realization of serial voltage regulator and consequently it´s experimental verification functions in low-voltage network.
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Model of electric energy storage with management system based on general assumptions
Sedlák, Miroslav ; Kopička, Marek (referee) ; Radil, Lukáš (advisor)
The accumulation of electricity as an issue is becoming more important and it’s importance is constantly growing. This is due to the fact that more renewable energy sources, mainly photovoltaic and wind power plants, are being incorporated into the electricity system, causing changes in the power grid performance. Changing in the behavior of consumers of electricity can cause further changes in the network. The ability for compensations of these changes in the power grid has just accumulation systems. This Thesis for Master’s Degree presents selected storage systems and ways in which energy can be stored. Further, in this work, a model of accumulation system with management based on general conditions will be created. This model will be tested and its behavior detected under the limit conditions.
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Model of electric energy storage with management system based on general assumptions
Sedlák, Miroslav ; Kopička, Marek (referee) ; Radil, Lukáš (advisor)
The accumulation of electricity as an issue is becoming more important and it’s importance is constantly growing. This is due to the fact that more renewable energy sources, mainly photovoltaic and wind power plants, are being incorporated into the electricity system, causing changes in the power grid performance. Changing in the behavior of consumers of electricity can cause further changes in the network. The ability for compensations of these changes in the power grid has just accumulation systems. This Thesis for Master’s Degree presents selected storage systems and ways in which energy can be stored. Further, in this work, a model of accumulation system with management based on general conditions will be created. This model will be tested and its behavior detected under the limit conditions.
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Electric networks with DC voltage up to 1000 V
Fiala, Martin ; Kopička, Marek (referee) ; Ptáček, Michal (advisor)
This master´s thesis deals with the proposal of DC low voltage network at a voltage level of 1000 V DC in Praskolesy u Mrakotina village. Direct distribution will be realized only at the terminal, which will power the village. Next part of this thesis is theoretical and its main focus is description of both DC and AC distribution systems. The proposed DC grid will use existing distribution grid. The thesis further describes the problems of long terminals in low voltage distribution systems and electrical installation in buildings. The result of this work is a comparison of the losses between AC and the proposed DC system. The last part deals with economical evaluation and technical solution for the proposed network variant, including their advantages and disadvantages.
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