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MV Cables Failures and Malfunctions
Holuša, Martin ; Pelikán, Luděk (referee) ; Krbal, Michal (advisor)
The aim of this diploma thesis is to define cable and his accessories and describe defects and fault which can appear on the cable and his accessories. The thesis also divides the cable and his accessories into individual parts, which are describe in more detail. Diagnostic methods that can be used to detect individual faults and monitor their status on individual parts of the cable and cable accessories are also listed. The thesis's practical part focuses on the test of one component of the cable assembly using PD measurement and monitoring its surface temperature.
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Sensors for electromagnetic detection of partial discharges
Pločeková, Natália ; Čáp, Martin (referee) ; Drexler, Petr (advisor)
Tato bakalářská práce se zabývá návrhem externího typu UHF sensoru, který bude umístněný na štěrbině transformátorové nádoby. V prvním kroku byl vlnovod-koax adaptér simulován v programu Ansys HFSS. Na základě poznatků byl zkonstruován sensor. Sensor využívá pro měření dva typy buzení vlnovodu, buzení proudovou sondou a buzení magnetickou smyčkou. Simulovaný a vyrobený sensor je porovnán z hlediska funčnosti a citlivosti.
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Optimalization of the die cast process of high-voltage transformers.
Borunský, Tomáš ; Fiala, Alois (referee) ; Maroš, Bohumil (advisor)
This thesis deals with choises of using mathematical statistics when optimising the compression casting process of high-voltage device transformer. There is a theoretical consideration to be found in the introduction which concerns the compression casting itself and all necessary information connected with it. Then there is a key numerical analysis part following. In the first instance there are variability problems of individual casting device discussed and then a regression analysis made to demonstrate and prove a link between the partial discharge and the key parameters of casting process. Finally an “optimal” casting sequence is suggested and alternative attitude problems with the assistance of Design of Experiments (DOE) are discussed.
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Diagnosis of high voltage capacitors for cascade voltage multiplier
Baev, Dmitriy ; Špinka, Jiří (referee) ; Krbal, Michal (advisor)
The main subject of the final thesis is to find a suitable method for measuring the partial discharge (PD) in the dielectric of high-voltage capacitor. In the theoretical part of my thesis contains from the mechanisms of origin and the harmful effects of partial discharge at high voltage insulation of capacitor. It describes the global galvanic method of partial discharge measurement, the principle of cascade voltage multiplier, its main components are high-voltage capacitor and diode, facilities quality measurement of capacitors for voltage multipliers, advantages and disadvantages and principles of HIPOTRONICS DDX-8003 with the pulse discrimination system. In the experimental part of the diploma thesis is familiar with the diagnostics of high – voltage capacitors by means of laboratory measurements on the electronic bridge and with the help of partial discharge measurement system. Design of suitable electrode arrangement is described which eliminates the influence of corona which makes it impossible to measure partial discharges and the dissipation factor (tg ). Analysis data from measurement and determination of quality level, eventual degradation of measured capacitors. The result of this project should be designed the methodology for finding of poor – quality capacitors in order to increase the reliability of the voltage multiplier.
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Faults identification of AC windings in production process
Samek, Josef ; Kurfűrst, Jiří (referee) ; Ondrůšek, Čestmír (advisor)
In this paper stator manufacturing process of stator is described. Mainly description is aimed on winding, insulation and copper wire. Discussion about origin of insulation damage possibilities during manufacturing is included. Statistics survey about failure causes of stator revealed during manufacturing process and warranty claims is presented. One test method from list of market available winding tests is chosen - partial discharge; described in detail and applied on the correct stator and the damaged stator. Results are interpreted.
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Insulation system of synchronous and induction motors for 18kV
Šporcr, Viktor ; Vetiška, Vojtěch (referee) ; Ondrůšek, Čestmír (advisor)
Bachelor’s thesis is divided into two separate sections. First part is concentrated on insulation system of high voltage machines impregnated by vacuum pressure impregnation. This part of semester thesis concisely describes the composition of individual components used for construction insulation systems of air and water cooled rotation machines. Second practical part contains evaluation of dielectric resistance of coil set with insulation system designed for voltage level 18 kV. This part contains a short description of used insulations. Further includes a report of dielectric tests of used coil set. This set of coils was tested on following tests. Heating measurement semi conductive tape with infrared camera at impulse voltage. The coils was exposed to impulse voltage for one 100 hours and sinus voltage for one 1000 hours. Before and between, aging was measured value of charge partial discharges and dissipation factor.
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Partial discharge
Macek, Vratislav ; Krbal, Michal (referee) ; Toman, Petr (advisor)
The main subject of this diploma’s thesis is the creation of laboratory task on the partial discharge. The thesis is made up of two parts: theoretical and practical. In the theoretical part there are information about partial discharge. One of them is classification partial discharge by type, effects of partial discharge in insulation systems, parameters to assess the quality of electrical insulation of power systems and measurement techniques. Further part is user’s manual for measurement instrument. In practical part is created laboratory task on problematic of the partial discharge measurement. It is demonstrative measure of partial discharge with the aim of understanding problematic of partial discharge, calibration and noise.
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Diagnosis of high voltage capacitors for cascade voltage multiplier
Baev, Dmitriy ; Zatloukal, Miroslav (referee) ; Krbal, Michal (advisor)
The main subject of the final thesis is to find a suitable method for measuring the partial discharge (PD) in the dielectric of high-voltage capacitor. In the theoretical part of thesis contains from the mechanisms of origin and the harmful effects of partial discharge at high voltage insulation of capacitor. It describes the global galvanic method of partial discharge measurement, the principle of cascade voltage multiplier, its main components (high-voltage capacitor and diode). Nowadays are presented the possibilities of measuring the quality of capacitors for voltage multipliers. In the experimental part of the diploma thesis is familiar with the diagnostics of high – voltage capacitors by means of laboratory measurements on the electronic bridge and with the help of partial discharge measurement system. It describes the design of a suitable electrode arrangement that eliminates the influence of the corona, which makes it impossible to measure partial discharges and the dissipation factor tg . The thesis analyzes the obtained data from measurements and determines the quality level or the degradation of the measured capacitors. The result of the project should be designed the methodology for finding poor quality capacitors in order to increase the reliability of the voltage multiplier.
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Partial Discharge in Electronic Equipments
Mammadov, Anar ; Maschke, Jan (referee) ; Dřímal,, Jiří (referee) ; Boušek, Jaroslav (advisor)
Tato disertační práce se věnuje studiu částečných výbojů (PD) způsobených poklesem spolehlivosti a životnosti elektronických zařízení a systémů. Diagnostika PD je dnes známá metoda pro vysoké napětí u vysoko-výkonných zařízení. V případě elektronických zařízení PD testování není ale běžně používáná metoda, přestože je zde také potenciál pro vysoké elektrické zatížení vzhledem k velmi krátké vzdálenosti. Tato práce je zaměřena na vyšetřování PD činnosti u elektronických zařízení. Bylo navrženo a provedeno pracoviště pro diagnostiku PD v elektronických zařízeních. Pracovní frekvence se pohybuje od několika stovek Hz až 100 kHz. Maximální amplituda PD testovaného napětí je vyšší než 10 kV. Navzdory jednoduché konstrukci toto zařízení přináší vysokou spolehlivost měření. Více než 300 PD testů bylo provedeno na různých elektronických zařízeních a elektronických součástí,např. na planárních transformátorech a elektronických komponentách používaných při vysoko-napěťových měničích
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