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Design of supply network configuration for large engineering company
Němec, Jan ; Holoubek, Jiří (referee) ; Topolánek, David (advisor)
This master-thesis analyzes issues of suggestion configuration of power supply network of industrial business. The option of the scheme of the configuration, the voltage level, the way of compensation of the reactive power, the way of the suppretion of the energetic interference and other requirements is included in the main tasks. This option has to be convenient with the requirements of the industrial business. The important point of this proposal is to prevent the influence of the superordinate distribution network. The compensation which keeps the power factor in the prescribed limits is one of the precautions against the influencing of the network. The second precaution is the elimination of energetic interference. The higher voltage, the fluctuation and the asymmetry of the voltage are the interferences which have the biggest impact on the industrial networks. The master-thesis offers the summary of the possibilities and ways of the elimination of the basic elements of the energetic interference.
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Power Factor Controllers for Switch-Mode Power Supllies
Gálus, Matej ; Steinbauer, Miloslav (referee) ; Murina, Milan (advisor)
The aim of this thesis is to design an active power factor correction (PFC) circuit for correcting a power factor of a switching power supplies. Various possible causes of bad AC mains power factor are discussed. Differences between linear and non-linear loads’ behaviour to AC mains are recognized and discussed. Various passive and active solutions for correcting current displacement and harmonic distortion are reviewed. Boost converter with quasi-resonant switching controlled by Texas Instruments’ UC3855 is chosen for highest total power factor for given power level against other topologies and its high efficiency and lower EMI against traditional boost converter. Various circuit parameters are simulated using PSpice. Complete circuit diagram for an 1kW output power level and worldwide mains voltage compatiblity is designed. After the device prototype was constructed, efficiency measurements were made and measured values are less than expected. This was apparently caused mainly due to absence of saturable reactor and implementation of resistive damping of the quasiresonant circuit’s parasitic resonance. Measured values of power factor are, however, very high and do meet the design expectations.
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Reactive power compensation in Petrochemie company using a passive power factor correction system instead of synchronous generators
Martinák, Rostislav ; Žila, Drahoslav (referee) ; Drápela, Jiří (advisor)
This thesis deals with the reactive power compensation, namely the possibility of reactive power compensation in Petrochemie company using a passive power factor correction system instead of synchronous generators, as part of the contract Kompel company. The thesis analyzes problems of definition of power in circuits with sinusoidal and nonsinusoidal voltages and currents. Furthermore, this thesis describes the power factor correction systems used in the low and medium voltage industrial and distribution networks. The last four chapters contain description of the existing state of power plant in Petrochemie company. There are considered the possibility of use of existing power factor correction system owned by company. The new static power factor correction system is suggested and functionality of power factor correction systems is verified through the simulations.
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Optimization of the active load of the source with dynamic output parameters
Halama, Petr ; Steinbauer, Miloslav (referee) ; Jirků, Tomáš (advisor)
This bachelor’s thesis deals with Power Factor Correction circuit, meant for the adjustment of the non-linear power source. Usually the PFC is designed for the power levels in the range of tens of Watts and more. New circuit will work at the power levels of maximally 1 W. Such control algorithm was designed, that the circuit represents the constant real load for an energy source. In the beginning of the work the Step-up converter topology was chosen as the best for next solution. More active PFC types were reviewed with the help of PSPICE simulator. In the next part of this project two of the analyzed circuits were implemented. Basic PFC for the demonstration of its principle and the half-bridge topology, which was selected on the basis of the analysis results.
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Micro Hydro Power Plant
Rusnák, František
This paper deals with realization of functional model of control unit for micro hydropower plant. Main task of this work is realization rectifier with active power factor correction,which is used instead of commonly used frequency converter. Control unit is designed for asynchronousmotor in generator operation with self-excitation. The propeller turbine is used as propulsion.To convert rectified voltage from PFC rectifier to mains will be used solar inverter.
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Functional model of a small hydro power plant control unit
Rusnák, František ; Arm, Jakub (referee) ; Benešl, Tomáš (advisor)
This semester work deals with realization of functional model of control unit for hydroelectric power station. Main task of this work is realization rectifier with active power factor correction, which is used instead of commonly used frequency converter. Control unit is designed for asynchronous motor in generator operation with self-excitation. The propeller turbine is used as propulsion. Theoretical part includes theory of the PFC converters. Practical part includes calculations for components of PFC converter and assembly of DPS PFC converter.
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DC-DC converter for onboard charging of electric vehicles
Holub, Miroslav ; Červinka, Dalibor (referee) ; Folprecht, Martin (advisor)
This master thesis deals with design of DC-DC converter for onboard charging of electric vehicle. Developed converter will mainly be used for charging stationary traction battery in laboratory. Output voltage of this charger will be adjustable by user in between 200 V and 450 V depending on the current charged battery configuration. Output current limit is set at 8 A. Since the converter will be supplied from standard household socket, the problem of power factor correction must be solved during the design. That is because a large part of this thesis is focused on describing the problematics of power factor correction. After that, active PFC module is designed, completed and performance of this module is verified. To achieve low overall losses and thus be able to keep small volume of the system, modern switching components based on Silicon Carbide were preferred. Beside laboratory use, completed system will be used to emphasize volumetric difference between onboard chargers based on old versus modern switching components.
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Precise LED lamps dimming for stage technology
Šojdr, Marek ; Šteffan, Pavel (referee) ; Levek, Vladimír (advisor)
This bachelor´s thesis discusses the problems of dimming of LED bulbs using DC voltage. It explains basic converters topologies and power factor correction options. Part of the thesis deals with the subharmonic oscillation and possibilities of its elimination. Describes the design of the circuitry of dimmer module for precise dimming of selected types of LED bulbs, revival and testing of the dimmer module. Part of the work is basic for realization of the dimmer (printed circuit board, list of components).
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Reactive power compensation systems
Lakomý, Marek ; Paar, Martin (referee) ; Drápela, Jiří (advisor)
Bachelor‘s thesis deals with the compensation of reactive power, which enables improved power factor correction. The theoretical part includes an explanation of basic concepts of the theory of reactive power compensation, the basic allocation of compensating equipment, their description and basic computational relations. Simulation of compensation devices, making laboratory models and measuring their parameters were realized as the practical part of the thesis.
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The reactive-power compensation of the industrial consumer
Mišinger, Ondřej ; Bok, Jaromír (referee) ; Toman, Petr (advisor)
The work deals with reactive-power compensation (power factor correction = PFC) at low and medium voltage. The theoretical part is focused on explaining the basic concepts of power factor correction and the reasons why the PFC is made. There is stated the basic allocation of PFC. Attention is devoted mainly for detuned PFC, which is nowadays often used because of the large number of nonlinear loads installed by customers. There are listed also the basic computational relations. Moreover, there are described the basic elements of compensation devices, which are capacitors, detuning reactors, contactors and power factor regulators. The practical part is dealt with power factor compensation for a particular industrial customers. There are offered several variants of the technical implementation of the PFC. These various options are compared from both technical and economic terms.
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