National Repository of Grey Literature 136 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Testing of the experimental model of the distribution system 22 kV
Musil, Milan ; Topolánek, David (referee) ; Novotný, Jan (advisor)
The aim of this project is practical verification and finding of the main parameters of model elements (lines, transformer, suppresion coil). This supresion is needed for eventual model testing of faults that might occur in the configured distribution network. The measurement was done using the equivalent model and computing zero-sequence impedance or admittance and their parts. Also it was necessary to find out the parameters of transformer, which consisted of a force measurement. Another part of thesis deals with the proposal of the new model elements. The most important of them is the model of switch, witch needed to protect model and the surroundings during nonstandart network conditions (faults).
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 %.
Testing of Distance Protection
Řehoř, Jiří ; Topolánek, David (referee) ; Orságová, Jaroslava (advisor)
The testing of distance protection in bachelor´s task is made a distinction between protection, requirements and relegation. This testing is also consisted in principle of function, describing terms of distance protection and comparing with time-current characteristics. The next step after short estimation was describing digital distance protection SIPROTEC 7SA511. The advantages are included in this estimation. The next part contains some configurations and connections with a test equipment in order to take control of measuring through the computer. The extended configurations are also comprised of two programms – DIGSY and TZO3. We had to make a suggestion of suitable methodics for measuring a time-current characteristic. We carried out three measurements where the test equipment was set to role of type TREND. A magnitude is generated at the output that is changed linearly in time with required rate (speed). We changed a current IX1 for our measurements that was undertaken with a rate of current rise. This process was given by a test equipment when the set values were constant. In the second measurement we modified a size of shift phase in the test equipment. In the third measurement we tried to set up different sizes of particular impedance characteristics (zone) inside of the distance protection where was set a neutral breaking time for the measured zone. On the contrary, the previous measurements had an absolute time.We have introduced evaluated results of measuring and observations in the end of this bachelor’s thesis.
Appropriateness of modelling the actual soil model as a uniform or horizontal two-layer soil model
Kuběna, Michael ; Topolánek, David (referee) ; Vyčítal, Václav (advisor)
The present thesis deals with soil resistivity and especially the suitability of replacing various soil models with a two-layer horizontal model. First, the factors that influence soil resistivity as well as the methodology of its measuring are described, and various soil models are introduced. Then, the Ansys program was used to create several soil models: a vertical model with perpendicular or oblique division, a model with a pronounced inhomogeneity and a three-layer model. In all of these models, a Wenner measurement simulation was performed, followed by a two-layer horizontal replacement model. Then the size of the error that was created by replacing the actual model with a two-layer horizontal model was examined.
Dynamic Compensation of Reactive Power
Horenský, Martin ; Topolánek, David (referee) ; Drápela, Jiří (advisor)
This master’s thesis is focusing on compensation of reactive power, especially on creating demonstrative model of static var compensation unit (SVC). Main topic of thesis is to apply this device for fast balancing dynamic conversions of recieved reactive power. In theoretical part is described suitable method for determination of instantaneous power. Next, there is basic description of all means used for compensation of reactive power and detailed description of the SVC compensator. Practical part includes design of compensation unit and control program in LabVIEW. The pq theory is implemented for detection instantaneous power. The results of validating functionality of compensator are presented in the last part of thesis.
Voltage profile regulation in LV distribution systems by means of OLTC equipped distribution transformer and series transformers based on distributed monitoring data
Hála, Tomáš ; Topolánek, David (referee) ; Drápela, Jiří (advisor)
This diploma thesis discusses two major topics. The first one is the control size of the voltage in LV networks in regard to the increase in distributed generation concered to renewable energy sources. The study contains a review focused on the current state of low voltagegrid followed by a proposal for the solution of the oncoming state. The solution is identified as a deploying OLTC distribution transformer. In the case of more complex topology is deployed a series voltage transformer. Both methods are part of the Smart Grid. The thesis also analyzes the issue of the data measurement and data transmission. The second part of the thesis consists of the description of selected control strategies and their simulations. The design of individual system elements in the PSCAD is described. From these elements, a test network was constructed and tested the individual simulation scenarios.
Primary testing of the protection relays
Macek, Vratislav ; Topolánek, David (referee) ; Toman, Petr (advisor)
The main subject of this bachelor’s thesis is the creation of laboratory task on the issue of primary injection testing of the protection relays. The thesis is made up of two parts: theoretical and practical. In theoretical part there are information concerning the issue of protecting. One of them the meaning and relay function, requirements applicable on them, failure states, which may arise on the device operation, description of instrument transformers and methods of testing relays. In practical part is created laboratory task on the issue of primary injection testing of overcurrent relay, of which will demonstrate the influence of load current transformer to its function. In task are used Overcurrent and Earth-fault protection REJ 525A and measuring instrument Omicron CPC 100.
Analyses of the breaker/limiter functions for low voltage supply points
Bajánková, Denisa ; Toman, Petr (referee) ; Topolánek, David (advisor)
The diploma thesis provides an insight into the remote control and disconnection of DSO supply points phenomenon. The remote or local disconnection/connection of supply point is allowed by the breaker function. The automatic disconnection of supply point is enabled by the limiter function. Due to the anticipated implementation of smart meters in the Czech Republic in the future, this work contains the comprehensive description of breaker/limiter function with proposed possibilities of use in the Czech Republic. The thesis deals with the current breaker/limiter function use in the Czech Republic and in other countries. It introduces the smart meter installation in pilot projects to analyze the breaker/limiter function use in other countries. The thesis is focused on the technical solution of breaker/limiter. Moreover, it describes the ways of connecting the breaker, settting the limiter, connecting/disconnecting a supply point and breaker operation. Further, the thesis introduces the ways of activating the breaker by a customer and defines in which cases it is possible to limit and interrupt the electricity supply in the Czech Republic currently. The main aim of thesis is to describe the specific possibilities of breaker/limiter function use in the Czech Republic. With regard to the function use in other countries and the limiting or interrupting the electricity supply by DSO according to energy law, the possibilities of use are proposed. Each possibility of use is analyzed when implementing the breaker function or the breaker/limiter function. The benefits are defined for a DSO and for a customer. The proposed uses are evaluated in terms of applicability and valid legislation in the Czech Republic. The result of this work is the summary of information about breaker/limiter function which is one of the new features in the implementation of smart metering. The function installation and the implementation of possibilities described in the thesis depends on the DSO decision.
Traction protection
Šüli, Nicolas ; Wasserbauer, Vojtěch (referee) ; Topolánek, David (advisor)
This bachelor’s thesis focuses on methods of protection for AC and DC traction systems. In thesis first deal with current state in traction, next with undesirable conditions and electrical protections. The work describes a draw in the program INKSCAPE two most often used traction power station with protection.
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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