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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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Models of distribution systems integrating distributed resources in PSCAD and simulation of chosen operational regimes
Bezecný, Ján ; Kopička, Marek ; Drápela, Jiří
The content of this Master´s Thesis is creating of dynamic models of distributed energy sources in PSCAD and their validation in chosen operation regimes. In the introduction of this thesis is summarized theoretical knowledge about methods for power systems analysis and there is a comparison of static and dynamic methods for power systems analysis. Static methods are used to calculate electric variables in grid nodes. In compare with them, dynamic methods are used to study instantaneous electrical and mechanical variables not only in grid nodes, but also at components of power system. Secondly, we individually designed distributed energy sources in according to requirements, we made a topology of distribution grid and we integrated these energy sources to the distribution grid. Finally, we chose some operation regimes, and studied a behavior of energy sources during these operation regimes.
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Analysis of Ferroresonance Overvoltage in Electrical Net
Bátora, Branislav ; Eleschová,, Žaneta (referee) ; Krejčí, Petr (referee) ; Toman, Petr (advisor)
This thesis deals with the ferroresonance phenomenon and ferroresonance overvoltage in electric networks. That’s why the introduction part explains the theoretical basis of ferroresonance and its consequences in the power system. The work then focuses on the power system as a non-linear dynamic system and describes various analytical methods for solving these systems. These methods are further applied to diagnose specific systems. There are a number of various power system configurations susceptible to ferroresonance. The most frequent one is theoretically analyzed in this thesis and a number of recommendations are offered for reducing the ferroresonance phenomenon. The thesis further deals with the selection of suitable software for this computationally chal-lenging task. A number of different tools are considered and efficiently reduced to Matlab Sim-ulink and PSCAD software. Matlab Simulink and its SimPowerSystem Toolbox are used to ana-lyze the effect of hysteresis of the magnetic core of the transformer on the emergence and course of the ferroresonance phenomenon. Using PSCAD, various configurations of the power systems are compared in terms of possible emergence and course of ferroresonance and also to find the limiting conditions that increase the probability of this phenomenon. The possibility of using arti-ficial neural networks for ferroresonance diagnosis is also mentioned in this thesis. The final part provides a number of recommendations for design and operation of both new and existing power systems.
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Ground Fault Location in Compensated Distribution Network
Topolánek, David ; Janíček,, František (referee) ; Mišák,, Stanislav (referee) ; Toman, Petr (advisor)
The most widespread system of an earthing neutral point of a supply transformer in a MV network is an earthing through an arc-suppression coil. In this case of a resonant-earthed power system a fault current is compensated by the suppression coil and only residual current flows through a fault point. A value of the residual current is much smaller then a value of an original capacitive current of the network and is not dependent on the fault location. According to that reasons it is really complicated to fast and accurately determine the fault point location. Since nowadays used methods for the ground fault location inside wide distribution networks have a lot of disadvantages, the thesis is focused on a proposal of a new method for the ground fault location especially inside of a compensated network. The main reasons for a consecutive installation of power quality meters into distribution transformer substations are a power quality monitoring and a global evolution of an electrical network onto the “SmartGrids”. In case that all results from the meters are properly synchronized and centralized, new possibilities of control or of an evaluation of a network are enabled. This doctoral thesis proposes the possibility for the ground fault detection with an aid of synchronized records recorded on the low-voltage side of the distribution transformers 22/0.4 kV into the network equipped with automatics for short-time increasing of an active part of a faulty current. The described method uses a voltage drop evoked by connecting of the auxiliary resistor for location of the faulty section. The proposed method is tested with help of numerical model which presents a part of the distribution network Series of simulation are executed and correct function and force function of the method is reviewed. Finally the thesis describes real experiment and also a confrontation between simulation and real measuring, and also possibilities of method usage are commented.
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Model of microgrid with energy storage
Halás, Andrej ; Drápela, Jiří (referee) ; Kopička, Marek (advisor)
This thesis describes the operation , characteristics and operating conditions of microgrid with energy storage , provides insight into the benefits of using listed concepts . The first part deals with the description of microgrid systems, distribution and shows examples of its use. The second part describes individual elements of the storage systems, energy production and energy transformation used in microgrids . The third part describes the work with PSCAD software. The main goal is to design a micro grid model in PSCAD and validate its function.
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Models of distribution systems integrating distributed resources in PSCAD and simulation of chosen operational regimes
Bezecný, Ján ; Kopička, Marek (referee) ; Drápela, Jiří (advisor)
The content of this Master´s Thesis is creating of dynamic models of distributed energy sources in PSCAD and their validation in chosen operation regimes. In the introduction of this thesis is summarized theoretical knowledge about methods for power systems analysis and there is a comparison of static and dynamic methods for power systems analysis. Static methods are used to calculate electric variables in grid nodes. In compare with them, dynamic methods are used to study instantaneous electrical and mechanical variables not only in grid nodes, but also at components of power system. Secondly, we individually designed distributed energy sources in according to requirements, we made a topology of distribution grid and we integrated these energy sources to the distribution grid. Finally, we chose some operation regimes, and studied a behavior of energy sources during these operation regimes.
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Modeling and simulation of a hybrid micro grid in PSCAD environment
Moravčík, Martin ; Mastný, Petr (referee) ; Drápela, Jiří (advisor)
In the opening part of this master´s thesis there is given concept, description, usage and advantages of micro hybrid grids in comparison to micro grids and there are evolution steps towards hybrid grid. There is also a mention about economics of operation of these grids. In the second part of this thesis there are descriptions of devices that are suitable for usage in micro hybrid grids with emphasis on generators and accumulation possibilities. In the next part of this thesis there is given an approach and description for modeling of various components of hybrid grids in PSCAD environment. In the next part of this thesis there are given simulation results that were conducted on created model. Especially power balance in 24 hour operation of the grid with method for determining suitable size of accumulation and installed capacity of photovoltaics. And next there are showed responses from change of power from photovoltaics, next there is a transition to islanded mode and last there is showed the behavior of converter when the limits of accumulation are reached. In the final part of this thesis there are conclusions, fulfillment of goals of this thesis and possibilities of further study.
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Generating of the fault record for protection and fault indicator testing
Bažata, Petr ; Jinderle, Pavel (referee) ; Topolánek, David (advisor)
The thesis is focused on a presentation of a model creating which is followed by the simulation of running real network with using the compensatory elements to minimize the incurred failures. This thesis is divided into two thematic parts – the first theoretical one deals with the basis structuring of short-circuit faults and more detailed study of ineffective ground connection. Particularly this part attends to the problematic of a network description with extinguishing suppression. Using the compensation minimizes the impact of the failure state. A short-term fixing of a resistor improves the function of the ground-fault protection and helps to detect the outgoing section damaged by the defect. Furthermore the thesis indicates simulation programs, compares them and chooses the most suitable one for the next practical part. This is focused on a simulation of a real network run, together with elements for an effective defect-reduction or easier detection of ground connection. As a simulation of a ground short-circuit is the model in the end of the thesis modified on a network with an effective grounded bundle. Testing of the model correctness and creating a record of a model using the real ground protection settings is also one part of this thesis.
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