|
|
Low-speed Wind Turbines for Small and Medium Size Applications
Forró, Bálint ; Paar, Martin (referee) ; Procházka, Zdeněk (advisor)
Bachelor’s thesis deals with usage of slow-running wind turbines for small and medium applications, especially with Savonius rotor. In first part I described theoretical usage of wind and analysis of wind power plants. Next part describes advantages and disadvantages of Savonius wind rotor and its practical usage. Thesis is ended with engineering design of wind rotor of this type for according performance at specific wind speed.
|
|
|
The Continuity Indicators Calculation of E-ON ČR Distribution Network Segment
Girga, Eduard ; Černý, Pavel (referee) ; Paar, Martin (advisor)
The aim of this master’s thesis is calculation and analysis of reliability indicators of the company E.ON Česká republika, s.r.o. distribution network in the south Moravia territory (area of former Jihomoravská energetika) for the period of one year, from 1st November 2008 to 31st October 2009. We consider events incurred on overhead or underground lines of level of high voltage or directly connected with these lines. Events originated from extensive disaster interruption of electric energy supply caused by particularly unfavourable external effects are not considered, because network components can not be efficiently dimensioned on those influences. Known aspects of the events are time of origin, time duration, place and cause of failure inception. Analysis of reliability indicators is accomplished according to different point of view. The first aspect is the hours of day, during which the event lasted. The second aspect is the hours of day, during which the event incurred. The third one focuses component pointed as reliable for the origin of the event. The last standpoint is percentage load of the line outlet, on which the event occurred. We can ordain this load as the proportion of current flowing through the line outlet in the time of event inception and of the value of maximum current set up on the protection of the line outlet. Indications mentioned in the last sentence were searched in the dispatcher centre thanks to graphical interface of application RIS JME Brno. In the theoretical part of the work there is described the structure of distribution network and its fundamental influence on the continuity of electric energy supply, the ways of evaluation and increasing of electric energy supply reliability, regulation of continuity of electric energy supply with emphasis on regulation in the Czech Republic valid until 26th February 2010 and since 27th February 2010. The last theoretical part focuses on definition of failure and differentiation of failures according to various aspects.
|
|
|
Determination of electromagnetic field distribution around underground power cable
Gromotovič, Ivan ; Paar, Martin (referee) ; Vyčítal, Václav (advisor)
The thesis deals with the distribution of the electromagnetic field around the conductor in the way of laying the conductors. The paper describes the structure of the cables and their lettering. More detailed is described the underground cable and various ways of protecting the conductor against mechanical damage are shown. The functions of the locator of underground lines on the electromagnetic field principle are briefly described . In the practical part, in simulation software Ansys Maxwell has been designed models to simulate the layout of the underground line. The output of the thesis is the comparison of the results created by the simulations.
|
|
|
Voltage magnitude deviations in a low-voltage distribution network due to increase in impedance of Y-connected load node to ground and unbalanced load
Blažek, Ondřej ; Paar, Martin (referee) ; Drápela, Jiří (advisor)
This work deals with the issue of an unbalanced power load of a three-phase main load and the associated network load of a PEN conductor. The introduction discusses the various types of systems where the distribution networks are implemented. Followed by the description of network segments causing issues discussed in this paper. The theoretical part discusses the possible operating conditions which lead to balancing the flow of neutral current, also shows the relation of the size of countervailing power charges and the form of the network load. There are also hints of possible risks that the mentioned situations may cause to the network operation in terms of function and safety. The practical part deals with the mathematical simulation model created in MATLAB. There are simulations based on which there is a description of the network behavior for the cases of induced adverse factors. The conclusion summarizes the most important results and findings produced by the simulations.
|
|
|
Weak Points Analysis of Distribution Network in Municipality with High Numbers of Photovoltaic Sources
Sedlák, Petr ; Lunga, Jiří (referee) ; Paar, Martin (advisor)
The master‘s thesis deals with the issue of weak points of the distribution network in a municipality with high numbers of photovoltaic sources. Photovoltaic power plants are gradually being added to the current state of the electric power distribution network of a specific municipality, while changes in the network are being monitored. Due to the output of the highest possible power from the sources into the distribution system in compliance with the established rules, the thesis also describes network modifications. These established rules of connection and operation of resources in the distribution network and effects of injecting disturbances in the low voltage network are discussed in the theoretical part of the thesis.
|
|
|
Evaluation and Comparison of Power Quality Changes from Multiple Measured Points
Koštialik, Marek ; Kopička, Marek (referee) ; Paar, Martin (advisor)
This diploma thesis deal with the description of electrical energy quality in low voltage. A test data model is created in the thesis which can automatically evaluate the state of the quality of electric energy in terms of higher harmonic voltages in the MATLAB programming environment. To verify the correct design of the model, two possible views of simulated data are created in the form of tables and graphical dependencies. An user interface is created for more complex control of each model states of the data being considered.
|
|
|
Simulation of Broken Conductor in Distribution Network by ATP-EMTP Program
Pacula, Václav ; Novotný, Jan (referee) ; Paar, Martin (advisor)
When broken conductor will impact on the ground. In isolated networks to ground fault occurs. For fault detection is the most commonly used method of zero-sequence voltage. The principle of the method is the sum of the voltage in all phases in the symmetric systém is the sum zero. The aim is to compare this method with the method of symmetrical sequence method and timeshiftomg. The method of symmetrical sequences compares sequency currents. To change the status of the systemis changed period, this method is based on the time shift.For comparison is used the ATP-EMTP program, that simulates the electrical transients. In this program are designed network model in which, these methods are investigated. It is a simple model of an idealized model and part of distribution network. After the simulation waveforms of events are processed and the results found faultdetection. Protection used today are based on measurements of zero-sequence voltage. A newer method of protection that extends further the possibility of detection and localization.
|
|
| |
|
|
Differential protection of transformer.
Svoboda, Miloslav ; Paar, Martin (referee) ; Toman, Petr (advisor)
This bachelor thesis is divided into several chapters, which consist of two main parts of the work, theoretical and practical. In the theoretical part the work deals with disorders of electric network, causes and limit of their adverse effects. Further it theoretically analyses the function of electrical protection, requirements for the protection , their basic elements. Then there is described the principle and function of instrument transformers and the differential protection of transformers. The practical part of the work deals with protection for a specific transformer. The proposal involves the calculation of three-phase short-circuit, the selection of differential protection, the proposal of instrument transformers and settings of the protection function.
|
|
|
Comparison of Connection Conditions of Photovoltaic Systems in the Czech Republic and the Slovak Republic
Vašica, Radoslav ; Radil, Lukáš (referee) ; Paar, Martin (advisor)
The objective of this work is an analysis and a comparison of legislative conditions of the connection of the photovoltaic power station on the territory of Czech Republic (CR) and Slovak Republic (SR). Presented are the working procedures for connecting of the power station to Distribution Grid (DG) and requirements of individual documents needed for a successful connection. Listed are also circumstances, which are taken into account during the consideration of the influence for connection, for the safe operation of DG. In the work are discussed the ways of support of constructing buildings of the photovoltaic power plant and the principle of repurchasing energy from renewable sources. The other part of work deals about hybrid photovoltaic power stations (HPPS), thus allowing to the power station to save energy into accumulators. There are the composition and principle of operation of the hybrid power stations. The following part deals with options of connectivity with hybrid power station to the DG. There are explained the advantages and disadvantages of connected and unconnected hybrid power plants to the DG.
|
guest ::
