National Repository of Grey Literature 65 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
LED lamps clasification regarding voltage flicker sensitivity
Štefek, Roman ; Baxant, Petr (referee) ; Drápela, Jiří (advisor)
The master's thesis deals with the design and time optimization of the method designed to determine the classification of LED lamps due to their resistance to power supply fluctuations. Classification of LED lamps in the classification scale and their labelling by the classification index is the task of informing in a simple way those interested in the ability of a concrete light source to function properly, without disturbing flickering, in conditions of electromagnetic interference.
Single railway electrification system design
Svoboda, Ondřej ; Radil, Lukáš (referee) ; Pelc, Jiří (referee) ; Drápela, Jiří (advisor)
The main topic of the thesis is the design of single-track electrification of a direct current system of 3 kV and an alternating current system of 5 kV 50 Hz and then economically evaluate it over a period of 30 years. The work deals with basic traction systems and also deals with the calculation of main parameters of electric trains. The thesis describes in detail the procedure for the design of the electrification of the track and a partial introduction to the simulation programs that were used for energy calculations.
Distributed generation support for voltage regulation by means of power control
Majer, Šimon ; Vrána, Michal (referee) ; Blahůšek, Radim (referee) ; Drápela, Jiří (advisor)
This thesis is focused on voltage regulation in low voltage distribution system. It describes power management methods using photovoltaic inverters. The thesis describes the working PQ space of the inverter and the regulation characteristics of the active and reactive power in dependence on the voltage. The practical part focuses on the simulation of specific PQU control settings on the test models created in PSCAD. The model is used as a basis for real measurement. Outputs obtained from measurement and simulation are validated in the text. The last part of the thesis identifies limits for connecting resources with and without support.
Verification of the Vdip method on the physical model of the MV network
Krčál, Vít ; Drápela, Jiří (referee) ; Topolánek, David (advisor)
This Master's thesis is focused on creating of an algorithm which calculates changes of negative-sequence voltages and currents from their instantaneous values. That allows to conduct localization of asymmetrical faults in MV network in line with the Vdip method, which is based on monitoring the changes of negative-sequence components at distribution substations and at a sub-transmission station. The algorithm is being developed in Matlab environment with continuous implementation of partial procedures which are being assessed and compared with each other. A study of phasor estimating methods is carried out with pointing out related problems which are mainly caused by Ripple control and deviation of system frequency from its nominal value. Optimization precautions are designed to mitigate these problems. For elimination of the Ripple control effects a method based on averaging is presented. The deviation of system frequency is dealt with by resampling the original data recordings. The analysis processes are tested by both simulation signals and real measured data. The optimized algorithm enables precise calculation of negative-sequence components changes which is the main contribution of this thesis. The constructed algorithm is used in verification of the Vdip method on physical model of MV network. For these purposes a simple distribution network is created within which ground faults on different places and with different resistances are realised. The results of localization are not convincing which is mainly caused by specific features of laboratory power line models which are constructed with heterogenous parameters.
Comparison of conventional CT and VT with current and voltage sensors
Dvořák, Petr ; Drápela, Jiří (referee) ; Orságová, Jaroslava (advisor)
The diploma thesis deals with conventional transformers and current and voltage sensors. The first half of thesis describes mainly the basic concepts and accuracy classes of these converters used in electrical substations. The emphasis is given primarily on the differences. In the second half of thesis is presented an exact type of converters, which are installed in the substation Medlánky. There is an analysis of measured data from long – term monitoring from this substation and comparing the results from conventional transformers compared to the results from more modern sensors.
Electrical safety monitoring systems - Insulation monitors
Kurka, Robin ; Bátora, Branislav (referee) ; Drápela, Jiří (advisor)
This thesis deals with solving the problem of insulation monitoring devices (IMD). The aim is to monitor the isolation status in the healthcare system, thus in an isolated power supply (IT) called the medical IT system. A summary of the used means and the used solutions of the way of supply from the point of view of reliability and safety were made to solve the problematics of the medical IT system.The thesis is based on an analysis of the experience of the use of IMD in medical IT system and also provides instructions for using IMD depending on the extent of their functions. The result of this thesis is a design of the electric power switchboard medical IT system with insulation monitoring device. A partial result of this thesis is the technical layout of the components inside the switchboard cabinet and their setting by means of a communication bus.
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.
Effect of distributed generation on medium voltage 22 kV distribution system operation with a new 110/22 kV feeder
Konopová, Tamara ; Bráblík, Libor (referee) ; Drápela, Jiří (advisor)
This thesis deals with the issue of power flow analysis in a medium voltage (22kV) distribution network with a focus on the influence of distributed energy generation recources. At first the issue of operation of distributed energy resources and their reverse effects on the distribution system is presented in the thesis. Furtherly there are described their operational conditions from the legislation point of view. The part dealing with calculation compares two network configurations in terms of power quality and how the power quality is impacted by distributed energy resources. The attention is given to voltage conditions, short-circuit power, power conditions, losses and flicker. The first configuration corresponds to the real situation in the network, the other one is describing the changes after the new 110/22 kV substation implementation to the power supply area and the overal change of network configuration. The network model and run simulation is done using the E-Vlivy program.
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.
Power system operation with a large number of non-rotating power sources
Dohnal, Martin ; Drápela, Jiří (referee) ; Radil, Lukáš (advisor)
This diploma thesis deals with the simulation of various operating situations in the network with many non-rotating power sources, especially focusing on frequency stability. Non-rotating power source is any source that delivers its power to the grid via power electronics. The first part of the thesis describes power system of the Czech Republic and its future development. In the next section, there is short description of today's most common non-rotating power sources. The third part deals with power regulation of the frequency in the grid. The following part describes the models of electrical circuit created for use in PSCAD simulations. The penultimate part describes simulations performed on a model of the network with many non-rotating power sources, which also includes rotating sources. The last part describes simulations performed on a model of the network that is composed of non-rotating power sources only.

National Repository of Grey Literature : 65 records found   1 - 10nextend  jump to record:
See also: similar author names
2 Drápela, Jakub
2 Drápela, Jan
1 Drápela, Josef
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