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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.
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The development of the model of PV system for electric water heating
Sochor, Tomáš ; Radil, Lukáš (referee) ; Ptáček, Michal (advisor)
This thesis deals with designing of a model of a photovoltaic system for domestic water heating in program PSCAD. In theoretical part, an analysis of photovoltaic systems regarding their connection to electrical grid is made. Then a description of chosen concepts of photovoltaic systems for domestic water heating is made. Furthemore, a photovoltaic cell is described with regard to its mathematical description and influence of different parameters on its volt-ampere characteristics. Also, a common topologies of DC-DC converters are described. Control is also related to these converters, that is why a fundamental MPPT algorithms are described. Practical part deals with designing of chosen concepts of photovoltaic systems for domestic water heating in program PSCAD. A basic simulations with regard to behavior of these systems are performed, especially a relationship with respect to irradiance and temperature. Simulations are then discussed in the conclusion.
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Energy self-sufficiency of small sewage treatment plant
Leksa, František ; Pěcha, Jiří (referee) ; Ptáček, Michal (advisor)
The thesis presents basic information from the area of small wastewater treatment plants. It also deals with the theoretical description of the solar radiation issue and describes the modeling of the photovoltaic cell and the selected type of battery. On the basis of the theoretical knowledge obtained, a model of the system representing the cooperation of the wastewater treatment plant with other energy sources is proposed. The model is created in PSCAD system and its function is verified in several operating scenarios. Depending on this, the work evaluates the achievements of individual operating scenarios that demonstrate different energy requirements for the system as a whole.
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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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Modelling and Simulations of Electromechanical Transients is Electrical Power Systems
Gromotovič, Ivan ; Bátora, Branislav (referee) ; Koudelka, Jan (advisor)
This work deals with the issue of evaluating transient stability in the simulation program PSCAD. Factors affecting transient stability were analyzed on a single-machine SMIB model. The results of this analysis confirmed the theoretical assumption that for more accurate results of the analysis of transient stability, it is necessary to consider the mentioned factors. A short circuit was simulated on the IEEE9 test model and subsequently the load angles of the generators were monitored using various methods. The method of reference of the largest generator in the system proved to be a more suitable method for the assessment of relative load angles from the results of the analysis.
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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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Autonomous and dispatching control of distributed power generating plants operated in the HV distribution system
Dvořáček, Jiří ; Jurík, Michal (referee) ; Drápela, Jiří (advisor)
Theses focuses on the evaluation of the possible means of active and reactive power control of generating units connected to medium voltage. First part summarizes analysis of Czech Republic medium voltage distribution grid. It summarizes means of autonomous and dispatcher control of generating units with respect to European Comission directive RfG, standard ČSN EN 50549-2 and national implementation PPDS. Following parts provide description of generating unit and distribution grid models used for simulation in PSCAD. Last part focuses on evaluation of results obtained via simulating steady-state scenarios as well as continuous simulation.
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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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