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Safety of off-grid hybrid energy system operation
Orság, Štěpán ; Vrána, Michal (referee) ; Morávek, Jan (advisor)
The thesis deals with the safety of hybrid systems in island operation. The safety requirements for electrical installation with photovoltaic system and protection against electric shock are discussed. Hybrid battery systems have a lower short-circuit performance in islanded operation, compared to parallel operation with the distribution grid, so the thesis focuses on the specifics of islanded operation and the use of protections that are part of the PV inverter or electrical installation. The work includes the design of test procedures and measurements on selected inverters with subsequent evaluation and recommendation of further protection measures.
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Projet of reconstruction of the 22 kV incoming substation and the cable network in the faculty hospital campus
Komárek, Filip ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This master's thesis deals with the area hospital distribution networkand one of the hospital's entry substation. The first part of this master's thesis deals with the project of the new cable network, her gradual revival without any power outages at the collection points. Futher, in this thesis is project of temporary transformer station for supplying power during the reconstruction of the HV switchboard. Subsequently, in this thesis is project of the new HV switchboard in one of the entry substation. new HV switchgear and a new HV substation were projected. Futher, in this thesis is proposed compensation of the whole area, including the HV network.
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History of protection relays
Šafl, Pavel ; Koudelka, Jan (referee) ; Bukvišová, Zuzana (advisor)
The bachelor thesis deals with mapping the origin and history of electrical pro-tections. The work outlines the circumstances and the new types of protection. It expla-ins and introduces problems encountered in the development and operation of historical protections. On the overcurrent protection AB31, AT31 and REF615, the tripping characte-ristic was measured to evaluate and compare modern digital protection and historical electromagnetic protection. Dependent protection AB31 has been tested and measured for its dependent characteristics and the AT31 protection has been checked for short-circuit current capability. Both of these protections were compared and evaluated with the REF615 digital protection. The measurement results and calculations are processed into well-arranged tables and graphs that are part of the work. The last part of this thesis is the selection of suitable protections for describing and making small exposures.
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Design of Protection Relays for MV Distribution Grid
Sochor, Tomáš ; Bukvišová, Zuzana (referee) ; Toman, Petr (advisor)
The master´s thesis deals with the design of medium voltage power line protection and the calculation of reliability indicators. First, it deals with the possibilities of power system operation. Subsequently, it divides the networks according to the grounding of the transformer node and the switching elements and devices occurring in the MV distribution network are mentioned. It presents the basic classification of power line protection and its use, especially it focuses on overhead and cable MV power lines. It also discusses the reliability of the power supply and lists the basic reliability indicators and their possible calculation. The practical part describes the changes in the considered area of the distribution network, where the reconstruction of the power line VN872 and a new way of powering the village Drnholec will take place. The impact of this change on the reliability of the supplied energy is also calculated. Furthermore, the protection of the power line is designed and the correctness of its setting is then verified on the model in the PSS Sincal software.
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Measurement of mechanical and electrical quantities of bimetals
Kocian, Štěpán ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
This bachelor thesis focuses on bimetals. In the theoretical part is described the principle of operation of bimetals, then important parameters of bimetal, including mathematical equations. Furthermore, methods of heating bimetals are mentioned and mathematically described. The last part in theory concentrates on the standards related to the use of bimetals as circuit breakers and the corresponding agreed breaking currents. The practical part deals with measurements on bimetal. This is measurement of free deflection and the force generated by the bimetal depending on the temperature change. From the measured data, the characteristics and the dependences of the properties for bimetal were processed. The last chapter was devoted to the creation of laboratory work.
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The Protection System Working on Output of Electronic Sensor System Measuring Current and Voltage
Bajánek, Tomáš ; Jiřičková,, Jana (referee) ; Janíček, František (referee) ; Orságová, Jaroslava (advisor)
At present, there is a widespread use of alternative measurement technologies in electrical networks that include current and voltage sensors. Their use is closely related to the use of IEC 61850-9-2 for data transfer of measured values within the substation for the purpose of protection and measurement. The use of sensors and communication standard IEC 61850 together with high-speed Ethernet will simplify the concept of the arrangement of protection terminals in substations and enable the development of a new protection system based on central protection. The dissertation is focused on protection algorithms, which use the SV according to IEC 61850-9-2, and their implementation into the central protection model. Thesis describes development in the field of protection of substations and the currently available solutions using IEC 61850-9-2 and the principle of central protection. Thesis explains algorithms for selected protection functions - overcurrent protection, negative sequence overcurrent protection, logic busbar protection and differential protection. Further, thesis deals with the programming of protection function algorithms in LabView development environment in the form of a central protection model. The model processes data from a process bus according to IEC 61850-9-2 and sends a GOOSE message over Ethernet in the event of a failure. To verify the correct function of the programmed protection algorithms, a testing procedure was developed using OMICRON 256plus, the current sensor and the merging unit. The results of the testing of the central protection model and the proposed algorithms were compared with the results of testing the currently used protections. At the end, the thesis deals with the assessment of the benefits of central protection for protecting substations and the possibility of further utilization of the central protection model. The thesis highlights a new way of protecting the electrification system using digital data from MU transferred via the process bus described in IEC 61850-9-2.
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The small hydroelectric power station design
Kokeš, Petr ; Pěcha, Jiří (referee) ; Matoušek, Antonín (advisor)
The thesis deals with comprehensive design of the small hydroelectric power station in the particular site. There is the site description in the first part followed by evaluation of the hydroenergetic capacity of the watercourse and description of the inlet building and piping. Building and machinery part of the turbine hall is described in the next part. The electric part of the power station is worked up to wider scope and includes hydroalternator, switchgears incl. power for self-consumption, electric protections, cabling, transformer substation and high voltage inlet line. There is a description of the control system in the next part and economical evaluation of the investment is at the end.
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Overcurrent protection relay testing using tester TZO3.
Vavreczky, Gábor ; Paar, Martin (referee) ; Toman, Petr (advisor)
The main task of this bachelor’s tesis is testing digital protection 7SA610 from Siemens. Purpose of the project is to take up with overcurrent functions of the protection, and realize it's testing through secondary tester TZO3. For this, the project grants theoretical foundations: deals with basic fault conditions in electrical networks, in detail describes the principle of individual types of overcurrent protections, grants informations about the used tester and about the used protection. In the final section of the thesis suggests applicable laboratory task in teaching at Department of Electrical Power Engineering, based on performed tests.
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Distance Protection Design Using Digital Input Data
Wannous, Kinan Hasan Wafaa ; Müller,, Zdeněk (referee) ; Braciník, Peter (referee) ; Toman, Petr (advisor)
Standard IEC 61850-9-2 definuje přenos vzorkovaných měřených hodnot (sampled measured values, SMV) prostřednictvím sítě Ethernet a využití SMV získaných ze slučovacích jednotek nebo přístrojových transformátorů. Implementace IEC 61850-9-2 závisí na vlastnostech datového souboru, jakými jsou časová synchronizace, počet vzorků a časový interval. Dizertační práce je zaměřena na algoritmy chránění a analýzu vlivu standardu IEC61850-9-2LE na fyzická zařízení ochran s analogově/digitálními vstupními daty o proudu a napětí. S ohledem na narůstající míru interakce mezi fyzickými zařízeními a komunikačními prvky byl navržen test pro analýzu komunikace pro rozvodnu využívající konvenční metody (analogové vstupy) a metody digitální založené na standardu IEC 61850-9-2. Práce dále popisuje funkci slučovací jednotky využívající standard IEC61850-9-2LE. Navržená metoda definuje zdroj SMV a analyzuje přenos dat. V rámci práce byl za využití softwaru Matlab naprogramován algoritmus ochrany. Vytvořený model je schopen vyhodnotit vliv harmonického zkreslení na funkci digitálních ochran a vliv přesycení proudového transformátoru na distanční ochranu. V práci jsou zhodnoceny i možnosti zrychlení testování systémů chránění s využitím neuronové sítě. Závěrečná kapitola se zabývá aplikacemi v reálném čase, využívajícími data z rozvodny v blízkosti Vysokého učení technického v Brně. K přenosu dat z rozvodny do univerzitní laboratoře je zde využíváno SMV přenášených optickým kabelem o délce 16 km. Aplikace je vytvořena v programu Matlab a je schopna číst data z ethernetového portu, dekódovat je, převést z formátu ASCII do desítkové soustavy a poté vykreslit průběhy proudu a napětí. Mezi vlastnosti aplikace se řadí jednoduchost použití, schopnost implementace funkcí distanční ochrany, výpočet RMS hodnot proudu a napětí a harmonického zkreslení, harmonická analýza prostřednictvím rychlé Fourierovy transformace a výpočet impedance poruchové smyčky. Všechny výpočty běží v reálném čase a provedena je i citlivostní analýza modelu.
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