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Short time overload of cables in UPS applications
Toman, Dominik ; Pravda, Luděk (referee) ; Šimek, David (advisor)
This bachelor’s thesis is about dimensioning power cables in electrical instalation which is described in the third chapter. If is used cable with small cross-section, relatively high direct current which is flowing through these cables could cause too high warming. Function of this electrical instalation and comparison of batteries which should be possibly used, are described in the first chapter. Second chapter shows risk of using cable with small cross-section, which could be overheated due to current overloading. Cables are designing in accordance with IEC 60364-5-52, IEC 60364-5-54 and duty cycle. Cross section values calculated according to all methods are very different. Cross section calculated in accordance to IEC 60364-5-54 and duty cycle are smaller then cross-section values calculated in accordance to IEC 60364-5-52. Cable with smaller cross section is cheaper, but it is possible that smaller cross section could cause bigger warming. This thesis also contains thermal model and warming measurement, both methods are for verification that cable with smaller cross-section could be used. Third chapter also contains calculations of voltage drops on all calculated cross-sections. Values from thermal model and warming measurement are different but they are both confirming that the cable with smaller cross section could be used.
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Calculation and measurement of disconnecter temperature
Šimek, David ; Dohnal, Petr (referee) ; Bušov, Bohuslav (advisor)
Bachelor‘s thesis is focused on the theoretical analysis of heating of electrical wires, electrical contacts and current necking in electrical apparatus. This bachelor’s thesis contains complete practical calculation of disconnector. The main part of work is experimental measurement of disconnector warming. The thesis points on possible causes of deviations between calculated and measured values.
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Testing of HV switch-disconnectors
Hanák, Zdeněk ; Dohnal, Petr (referee) ; Bušov, Bohuslav (advisor)
This project describes the problems of high voltage switch disconnectors and their requirements. In this project are described type tests which are done for high voltage switch disconnectors and for testing their characteristics. Further was also performed measurement and calculation of warming on outdoor switch disconnector.
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Design and implementation of a workplace for temperature rise testing
Bartek, Zbyněk ; Bušov, Bohuslav (referee) ; Šimek, David (advisor)
This master thesis deals with design and implementation of a workplace for temperature rising measurement in electrical devices. The thesis deals with contact and non-contact temperature measurement, with the current equipment of the laboratory of switching devices used to measure temperature rising, and also deals with normative requirements for temperature rising tests for specific electrical devices and their systems. The next part of the thesis lists requirements for workplace design and subsequently describes the workplace design with 3D models of individual parts. The practical part describes the implementation of the workplace, then the test measurements with the current equipment of the laboratory of switching devices and with the newly created workplace for temperature rising measurement. The end of the work deals with the evaluation of the new workplace and the possibilities of further improvement of the workplace.
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Testing of HV switch-disconnectors
Hanák, Zdeněk ; Dohnal, Petr (referee) ; Bušov, Bohuslav (advisor)
This project describes the problems of high voltage switch disconnectors and their requirements. In this project are described type tests which are done for high voltage switch disconnectors and for testing their characteristics. Further was also performed measurement and calculation of warming on outdoor switch disconnector.
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Calculation and measurement of disconnecter temperature
Šimek, David ; Dohnal, Petr (referee) ; Bušov, Bohuslav (advisor)
Bachelor‘s thesis is focused on the theoretical analysis of heating of electrical wires, electrical contacts and current necking in electrical apparatus. This bachelor’s thesis contains complete practical calculation of disconnector. The main part of work is experimental measurement of disconnector warming. The thesis points on possible causes of deviations between calculated and measured values.
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