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Design of a 25 kV traction disconnector
Buchta, Martin ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
This diploma thesis deals with the design of a traction disconnector for 25 kV AC and a rated current of 800 A. The result should be a competitive disconnector that is capable of potential applications on domestic railways and should have parameters that other local manufacturers do not currently offer. This is, for example, electrical strength or the size of the rated current, which is an economic option for most railway lines in the Czech Republic. According to the proposed drawing documentation, the disconnector was assembled and then the selected disconnector parameters were tested. For example, electrical strength tests, short-circuit tests, constant current tests, etc. were performed. The calculated and measured values were compared together. The designed disconnector was financially and technically evaluated on the basis of test results and the construction itself. Finally, some appropriate adjustments were proposed.
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Single-phase DC/AC converter with output parameters 230 V / 50 Hz / 100 VA
Smolák, Martin ; Martiš, Jan (referee) ; Vorel, Pavel (advisor)
This master‘s thesis focuses on optimization of power and control circuits of an inverter, which was developed at UVEE. The principle of function and circuit implementation of a single-phase inventer, various calculations (design of an LC filter, DC link capacitor, semiconductor elements and heat sink) are described in the thesis. A design of fast overcurrent protections, oscillator and saw signal generator is included. Furthermore, a printed circuit board was designed which was optimized by thermal simulation in the Workbench Ansys. Subsequently, the printed circuit board was mounted, debugged and verification measurements were performed on it. At the end of the thesis there is a documentation for the implemented equipment.
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Calculating the temperature field distribution in an electrical machine
Haratek, Jiří ; Mach, Martin (referee) ; Janda, Marcel (advisor)
This diploma thesis deals with methods used to determine the temperature field distribution within an electric machine. The first part is focused on methods of temperature measurement, generation and transfer of the thermal energy within the electric machine, asynchronous motor in particular. The thesis describes classical methods of temperature measurement and it also deals with ANSYS Workbench finite element method for thermal analysis of the motor. The final part of the thesis is focused on a comparation of all discussed methods with respect to results of thermal test for real asynchronous motor and concludes the most proper method.
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The heat build-up of tap-off units of busbar trunking system in relationship to their surfacing.
Forejtník, Jan ; Radil, Lukáš (referee) ; Foral, Štěpán (advisor)
This study is dedicated to the effect of surface modification on lid warming of busbar trunking system BD2 which is manufactured by Siemens company in Mohelnice town (CZ). By using experimental methods, it investigates heat transfer by radiation and natural convection. It evaluates which type of surface modification is more effective by transfer heat. This study uses a method of emisivity comparison and a procedure given in standards for heat up test afterwards. It led to recognition, that various colour shades used on busbar system have similar high emissivity. Smooth colour spraying transfers heat a bit more effectively than rough colour spraying. Outputs of supplementary measurements give basis for numerical simulations in SolidWorks software. Numerical analysis assists to interpret results, for example by sensitivity study of heat transfer depending on emissivity.
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Comparison of the temperature-rise test of low voltage circuit breaker at different operating settings
Kusák, David ; Ing. Kamil Mikyska (OEZ s.r.o.) (referee) ; Dostál, Lukáš (advisor)
The bachelor thesis deals with the evaluation and comparison of the measured values of terminal temperatures of two molded case circuit breakers of the 3VA1 series in different operating settings. temperature rise test is carried out when the device is loaded with rated current and is used to verify whether some parts of the device do not exceed the permissible warm-up value according to the relevant standard. The theoretical part of the thesis focuses on the design, principle of operation and operating states of modular and molded case circuit breakers. Furthermore, a general description of the test conditions of the temperature rise test is presented. In the practical part of this work, 45 temperature rise testand calculation of the power loss of circuit breakers were carried out. breaker series 3VA12
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Design of a 25 kV traction disconnector
Buchta, Martin ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
This diploma thesis deals with the design of a traction disconnector for 25 kV AC and a rated current of 800 A. The result should be a competitive disconnector that is capable of potential applications on domestic railways and should have parameters that other local manufacturers do not currently offer. This is, for example, electrical strength or the size of the rated current, which is an economic option for most railway lines in the Czech Republic. According to the proposed drawing documentation, the disconnector was assembled and then the selected disconnector parameters were tested. For example, electrical strength tests, short-circuit tests, constant current tests, etc. were performed. The calculated and measured values were compared together. The designed disconnector was financially and technically evaluated on the basis of test results and the construction itself. Finally, some appropriate adjustments were proposed.
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Single-phase DC/AC converter with output parameters 230 V / 50 Hz / 100 VA
Smolák, Martin ; Martiš, Jan (referee) ; Vorel, Pavel (advisor)
This master‘s thesis focuses on optimization of power and control circuits of an inverter, which was developed at UVEE. The principle of function and circuit implementation of a single-phase inventer, various calculations (design of an LC filter, DC link capacitor, semiconductor elements and heat sink) are described in the thesis. A design of fast overcurrent protections, oscillator and saw signal generator is included. Furthermore, a printed circuit board was designed which was optimized by thermal simulation in the Workbench Ansys. Subsequently, the printed circuit board was mounted, debugged and verification measurements were performed on it. At the end of the thesis there is a documentation for the implemented equipment.
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The heat build-up of tap-off units of busbar trunking system in relationship to their surfacing.
Forejtník, Jan ; Radil, Lukáš (referee) ; Foral, Štěpán (advisor)
This study is dedicated to the effect of surface modification on lid warming of busbar trunking system BD2 which is manufactured by Siemens company in Mohelnice town (CZ). By using experimental methods, it investigates heat transfer by radiation and natural convection. It evaluates which type of surface modification is more effective by transfer heat. This study uses a method of emisivity comparison and a procedure given in standards for heat up test afterwards. It led to recognition, that various colour shades used on busbar system have similar high emissivity. Smooth colour spraying transfers heat a bit more effectively than rough colour spraying. Outputs of supplementary measurements give basis for numerical simulations in SolidWorks software. Numerical analysis assists to interpret results, for example by sensitivity study of heat transfer depending on emissivity.
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