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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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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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Ultra low noise switching power supply
Raba, Jaroslav ; Leuchter,, Jan (referee) ; Šrámek, Petr (advisor)
This thesis deals with the issue of switching power supply in terms of noise ratios in the output voltage. In the theoretical part analyzes the basic principle of classical and resonant topology switching power converters in terms of output voltage ripple and switching noise. There are also some possibilities of compensation to minimize switching noise and output ripple. The second part describes the custom design a low noise switching power supply, which is composed of an active power factor corrector, power converters and ripple limiter. The main power converter is designed as an LLC resonant converter. The last part deals with the actual construction of the proposed source, its measurement and presentation of the results.
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The system of load matching to the energy converter
Halama, Petr ; Mandlík, Michal (referee) ; Drexler, Petr (advisor)
This master’s thesis deals with energy harvesting from the mechanical energy sources. The mechanical energy may be converted into the electrical by means of a vibrational microgenerator. The thesis deals also with the production of energy from different renewable sources. There have been identified conditions for effective transformation of the remaining energy. In order to satisfy these conditions a circuit for load matching to energy harvester has to be used. Four variants of matching circuit have been designed and analyzed in PSpice or LTspice. It has been designed a system of power factor correction controlled by circuit with discrete components and also by microcontroller. For one of these variants a specific integrated circuit has been used. The designed circuits have been built and their parameters haven been determined by measurement.
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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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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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Power factor correction and low-frequency conducted disturbances assessment of an industrial induction heating system
Vývoda, Marek ; Žila, Drahoslav (referee) ; Drápela, Jiří (advisor)
This Diploma thesis deals with design of for power factor correction device for mid-frequency-range induction heating and also with assessment of correction device influence in harmonically distorted environment from the distribution net point of view. Research chapters contain of main characteristics of electrical power quality and theoretical background of reactive power, which is in our case caused by driven non-linear elements. Further, the heating power supply block is explained and simulations of power consumption in Matlab - Simulink is done, within the prove of corrective tools design. After the build of corrective tool assemblies, measurements are matched with the simulation results.
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