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Transient Thermal Response Measurements
Stejskal, Martin ; Čala, Martin (referee) ; Beneš, Petr (advisor)
This Bachelor thesis is interested in measurement of thermal parameters of three-phase power switching module. The module contains IGBT power transistors and power diodes, whose dynamic parameters are measured. Based on these measurements, substitute thermal models are constructed, necessary for heat loss simulations and calculations.
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Converter for high-speed induction motor
Veselý, Petr ; Pazdera, Ivo (referee) ; Procházka, Petr (advisor)
The semestral thesis deals with designing a frequency changer. It describes general information about induction motors and power electronics, focusing on pulse converters. Based on given parametres, appropriate components were chosen and described. Also, there is power loss calculated in this document, which is used for dimensioning cooling. Also an LC filter is designed in this dokument. At last, there is a printed circuit board designed for the power part.
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Utilization of FPGA circuits in multilevel inverters
Repčík, Juraj ; Pavlík, Michal (referee) ; Fujcik, Lukáš (advisor)
Tento projekt zkoumá vybrané způsoby implementace víceúrovňových měničů do praxe. V předložené práci je do hloubky prezentována tzv. ANPC (Active Neutral Point Clamped) pětiúrovňová topologie. Autor se v práci zaměřuje zejména na návrh technického řešení experimentálního vzorku a implementaci řídicích algoritmů jako jsou aktivní řízení napětí na pomocném kondenzátoru nebo aktivní balancování vstupního kapacitního děliče. Pro aplikaci zmíněných struktur byl vybrán moderní digitální integrovaný obvod, který slučuje mikroprocesor a FPGA do jednoho systému. Výsledný měnič umožňuje autonomní provoz a umožňuje generovat přesné a stabilní výstupní napětí.
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Power Inverter Online Diagnostics
Knobloch, Jan ; Chlebiš,, Petr (referee) ; Drábek,, Pavel (referee) ; Klíma, Bohumil (advisor)
This doctoral thesis focuses on the problems of IGBT failure prediction in pulse converters using measurable changes of selected parameters (so--called trending variables) being influenced of transistor degradation during aging. Firstly the state--of--the--art in this field is presented in the dizertation. The description of designed and constructed automated measurement stand follows, enabling monitoring and recording of switching processes during accelerated aging. Further the problems of high--bandwidth measurement of electrical quantities during IGBT switching are described. Especially the problems of current sensing are analyzed and the most suitable sensor is selected. The data recorded using the developed apparatus served to identify potential trending variables allowing the failure prediction. Here the dependence of trending variables on aging and on parasitic influences (current, temperature, voltage) had to be distinguished. Finally the evaluation of trending variables is performed. Their insignificant sensitivity on accelerated aging is shown which complicates their practical implementation for the purpose of failure prediction.
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Motor inverter for Formula Student
Macko, Maroš ; Tomíček, Pavel (referee) ; Šteffan, Pavel (advisor)
This thesis is focused on a power inverter for traction motors for a Formula Student car. Part of the work involves the design and implementation of this system. The main high-voltage power board design and the selection of suitable components are described. Furthermore, a secondary board is designed, which is used for communication and diagnostic measurements. All systems must comply with the rules of the Formula Student competition.
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Vývoj zařízení pro excitaci plazmatu a měření jeho parametrů
IŠKA, František
This bachelor thesis is focused on the design of high power switching power supplies for applications such as plasma excitation. In the teoretical part of this thesis some common topologies of switching power supplies and principles of their operation are described. Furthermore, theoretical part of this thesis deals with topics related to the designing of switching power supply such as principle of operation of power transistors, transformers and pulse width modulation. Practical part of the bachelor thesis is focused on design of power part of switching power supply with full-bridge topology, simulating of operation of its parts using Multisim programme, realization of this power supply and verification of its functionality by measurement.
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Power Converters For Cell Electroporation
Folprecht, Martin
This contribution refers about some topologies of power converters, which are used for medical purposes. The use of power converters in treatment of a cancer or an arrhythmia is a modern medical technique, which is still in development. The aim of the contribution is to compare current samples of power converters for medical purposes and briefly describe a design of a high-frequency power generator for AC electroporation.
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Estimating The Power Bjt Excess Charge Recombination Time Constant
Mikláš, Ján
The paper demonstrates an experimental way of estimating the excess minority carriers charge stored within the the power bipolar transistor in the saturation mode, i.e. with both junctions forward-biased, as a reference to future IGBT switching action analysis. The method is based on analyzing the transient turn-off base current waveforms at different conditions right before this event. The base current is known to supply the minority carriers within the device. Estimating the recombination time constant serves as a basal precondition for further identification of the excess charge storage depending on various operating conditions and retrospectively an accurate identification of power BJT and IGBT various partial stage of switching action.
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