ELEKTRYKA - Issue 1/2011 (217) - Politechnika Śląska, Wydział Elektryczny

ELEKTRYKA - Issue 1/2011 (217)

ELEKTRYKA Year LVII (2011)

QuarterlyIssue 1 (217)

Scientific Committee

CONTENTS

Foreword

Krzysztof GÓRECKI, Janusz ZARĘBSKI, Przemysław PTAK: Investigations of a BUCK converter with SiC semiconductor devices
Marcin MACIĄŻEK, Dariusz GRABOWSKI, Michał LEWANDOWSKI: Frequency analysis of harmonics flow for an active power filter model
Michał GWÓŹDŹ: Stability of discrete-time systems on base of generalized sampling expansion
Henryka Danuta STRYCZEWSKA: Atmospheric pressure cold plasmas. Generation, modeling and applications
Marta KOLASA, Rafał DŁUGOSZ, Aleksandra FIGAS: An influence of the neighborhood function on the learning process of the hardware implemented Kohonen neural networks
Maciej WŁODARCZYK, Andrzej ZAWADZKI: RLC circuits in aspect of positive fractional derivatives
Marek DŁUGOSZ: Minimal energy control of DC motor
Łukasz PUTZ, Ryszard NAWROWSKI: Higher harmonics analize in LED diode lamps used to illumination scenery
Marek Włodarski: Application of ROC analysis to bayesian classifiers of PERG signals
Omelian PŁACHTYNA, Zbigniew KŁOSOWSKI, Roman ŻARNOWSKI: Efficiency evaluation of average-step voltages method comparing to classical methods of numerical integration applied to mathematical models of electrical circuits

Krzysztof GÓRECKI, Janusz ZARĘBSKI, Przemysław PTAK

Katedra Elektroniki Morskiej, Akademia Morska w Gdyni

INVESTIGATIONS OF A BUCK CONVERTER WITH SiC SEMICONDUCTOR DEVICES

Summary. The paper deals with research of the influence of replacing silicon semiconductor devices by devices produced from silicon carbide in the BUCK converter on the converter characteristics. There are presented the measurement results of the considered converter obtained for three sets of semiconductor devices: a silicon MOSFET and a silicon diode, the same transistor and a diode from the silicon carbide as well as a MESFET from the silicon carbide and a diode from the silicon carbide. Investigations were performed for different values of the load resistance, as well as different values of frequency and the duty factor of the control signal.

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Marcin MACIĄŻEK, Dariusz GRABOWSKI, Michał LEWANDOWSKI

Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach

FREQUENCY ANALYSIS OF HARMONICS FLOW FOR AN ACTIVE POWER FILTER MODEL

Summary. A frequency model of an active power filter as well as its simulation investigation in Matlab/Simulink for dq control algorithm are presented in the paper. As a result, the quality of current compensation for selected harmonics as a function of the switching frequency and load power has been determined.

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Michał GWÓŹDŹ

Instytut Elektrotechniki i Elektroniki Przemysłowej, Politechnika Poznańska

STABILITY OF DISCRETE-TIME SYSTEMS ON BASIS OF GENERALIZED SAMPLING EXPANSION

Summary. Dynamic changes of parameters of energy sources and receivers are reasons for decreasing the accuracy of output signals in relation to the reference signals. The fundamental problem with developing such time-discrete systems, working in a closed feedback loop, is time delay in the signal path together with aliasing effects. The paper presents analysis of work of a current regulator with a multi-dimensional sampling system on a basis of extension of the Whittaker-Kotelnikov-Shannon (WKS) sampling theorem. The regulator is a part of the wideband power electronics controlled current source.

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Henryka Danuta STRYCZEWSKA

Instytut Podstaw Elektrotechniki i Elektrotechnologii, Politechnika Lubelska

ATMOSPHERIC PRESSURE COLD PLASMAS. GENERATION, MODELLING AND APPLICATIONS

Summary. The paper presents review of atmospheric pressure low temperature plasma sources, the main areas of their applications and chosen problems of gliding arc discharge modelling. Some modelling results are presented. The applications of cold plasma methods to ecology and bioengineering are discussed.

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Marta KOLASA, Rafał DŁUGOSZ

Zakład Podstaw Elektrotechniki, Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy

Aleksandra FIGAS

Katedra Inżynierii Komputerowej, Politechnika Poznańska

INFLUENCE OF THE NEIGHBORHOOD FUNCTION ON LEARNING PROCESS OF HARDWARE IMPLEMENTED KOHONEN NEURAL NETWORKS

Summary. The paper presents influence of a type of the neighborhood function (NF) on the learning process of the Kohonen neural networks. Four different NF and three topology were compared. The objective was to determine which NF is the most efficient looking both from the transistor level implementation and learning quality points of view. The effectiveness of the learning process of SOMs was assessed using two criteria: the quantization and topographic errors.

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Maciej WŁODARCZYK, Andrzej ZAWADZKI

Katedra Elektrotechniki i Systemów Pomiarowych, Politechnika Świętokrzyska w Kielcach

RLC CIRCUITS IN ASPECT OF POSITIVE FRACTIONAL DERIVATIVES

Summary. At present, the so-called supercapacitors, classic characteristics of which are not precise, arise high interest. To describe their characteristics one tries to use fractional derivatives that model a supercapacitor as a system built with RLC elements. In the paper the analysis of such circuits in transient state is presented. There is assumed that dependencies between currents and voltages in a coil as well as in a capacitor are described with fractional derivatives. There are given general solutions of such a circuit. For selected degrees of derivatives the obtained results are presented in diagrams.

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Marek DŁUGOSZ

Katedra Automatyki, Akademia Górniczo-Hutnicza im. S. Staszica w Krakowie

MINIMUM ENERGY CONTROL OF DC MOTOR

Summary. In this paper the minimum energy control of a DC motor is considered. In order to solve the presented problem the Hilbert space and the orthogonal projection theorem are used. Most computations for finding the optimal control can be carried out with a computer. Numerical experiments confirming the accuracy are also included in the paper.

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Łukasz PUTZ, Ryszard NAWROWSKI

Instytut Elektrotechniki i Elektroniki Przemysłowej. Politechnika Poznańska

ANALYSIS OF HIGHER HARMONICS IN LED DIODE LAMPS USED FOR SCENERY ILLUMINATION

Summary. The paper presents use of electroluminescence diodes (LED). The structure and principles of operation of the diodes are presented. The paper shows positive and negative aspects of LED diode operation. The main part of the paper includes presentation of preliminary study of electroluminescent light sources taking into account generation of higher harmonics. The results provided the plots of the voltage and current harmonics contents in phase and neutral conductors. The characteristics obtained this way have been thoroughly analysed.

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Marek WŁODARSKI

Katedra Elektrotechniki Teoretycznej i Informatyki, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie

APPLICATION OF ROC ANALYSIS TO BAYESIAN CLASSIFIERS OF PERG SIGNALS

Summary. This paper presents use of ROC analysis for assessment of the classifier performance. Either linear or quadratic discriminant analysis assigns objects to classes on the basis of a parametric model. Fitting the decision boundary according to a nonparametric ROC curve allows achieving demanded criteria like the maximum accuracy, the minimum risk or Neyman-Pearson’s criterion. This method was applied to measure the quality of bayesian classifiers of PERG signal real data base.

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Omelian PŁACHTYNA, Zbigniew KŁOSOWSKI, Roman ŻARNOWSKI

Instytut Elektrotechniki, Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy

EFFICIENCY EVALUATION OF AVERAGE-STEP VOLTAGES METHOD COMPARED TO CLASSICAL METHODS OF NUMERICAL INTEGRATION APPLIED TO MATHEMATICAL MODELS OF ELETRICAL CIRCUITS

Summary. In the paper there is presented the effectiveness of the original method of numerical integration by prof. O. Plakhtyna. It was named the method of average-step voltages. The method is compared to classical methods of numerical integration applied to analysis of electrical circuits. The measure of effectiveness is the time consumed for integration of an equation system assuming the constant error between the analytical solution and employed for integration numerical method solution. The average-step voltages method enables more effective in comparison to the other methods. The theoretical description of the method is also presented in the paper.

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