ELEKTRYKA - Issue 1/2014 (229) - Politechnika Śląska, Wydział Elektryczny

ELEKTRYKA - Issue 1/2014 (229)

ELEKTRYKAYear LX (2014)

QuarterlyIssue 1 (229)

Scientific Committee

CONTENTS

Foreword

Lukáš KOUDELA, Petr POLCAR, Oldřich TUREČEK: Numerical modeling of sound propagation in anechoic chamber with quadratic residue diffuser
Petr POLCAR, Lukáš KOUDELA: Electromechanical systems with ferrofluid filled GAP
Tadeusz KACZOREK: Analysis of pointwise completeness and pointwise generacy of descriptor electrical circuits by the use of Drazin inverse of matrices
Krzysztof BUDNIK, Wojciech MACHCZYŃSKI, Jan SZYMENDERSKI: Electric field induced by current in overhead conductor
Ryszard PORADA, Adam GULCZYŃSKI: Control of power electronics current source with application of discreet regulators
Wojciech MITKOWSKI: Analysis of nonuniform electric LC-ladder network
Krzysztof GÓRECKI, Janusz ZARĘBSKI: Influence of the mounting of a semiconductor device on its transient thermal impedance
Andrzej ZAWADZKI, Maciej WŁODARCZYK: Application of fractional differential calculus used to modeling a class of nonlinear generators
Andrzej KUKIEŁKA: Dual similarity of voltage to current and current to voltage transfer function of hybrid active two-ports with conversion
Krzysztof SZTYMELSKI, Marian PASKO: B-H loop mathematical model

Lukáš KOUDELA, Petr POLCAR, Oldřich TUREČEK

University of West Bohemia in Pilsen, Czech Republic

NUMERICAL MODELING OF SOUND PROPAGATION IN ANECHOIC CHAMBER WITH QUADRATIC RESIDUE DIFFUSER

Summary. This paper discusses numerical solution of acoustic transient field in the anechoic chamber with quadratic residue diffuser. The goal is to obtain the time evolution of acoustic pressure when the source of signal is Gaussian monocycle pulse with defined parameters. The mathematical model is described by the partial differential equation supplemented with boundary conditions and the numerical solution is realized by a fully adaptive higher-order finite method implemented into codes Hermes and Agros2D developed at the University of West Bohemia.

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Petr POLCAR, Lukáš KOUDELA

University of West Bohemia in Pilsen, Czech Republic

ELECTROMECHANICAL SYSTEMS WITH FERROFLUID FILLED GAP

Summary. This paper deals with the possibility of improving the output characteristics of an electromechanical actuator by filling the air gap with ferromagnetic liquid. The enhancement assumption is theoretically derived, testing device is built and its static and dynamic characteristics are measured to confirm the theory.

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Tadeusz KACZOREK

Bialystok University of Technology

ANALYSIS OF POINTWISE COMPLETENESS AND POINTWISE GENERACY OF DESCRIPTOR ELECTRICAL CIRCUITS BY THE USE OF DRAZIN INVERSE OF MATRICES

Summary. It is shown that every descriptor electrical circuit is a linear system with regular pencil. The pointwise completeness and pointwise generacy of the descriptor electrical circuits is analyzed by the use of Drazin inverse of matrices. Conditions for the pointwise completeness and pointwise generacy of the descriptor electrical circuits are established and illustrated by an example.

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Krzysztof BUDNIK, Wojciech MACHCZYŃSKI, Jan SZYMENDERSKI

Politechnika Poznańska

ELECTRIC FIELD INDUCED BY CURRENT IN OVERHEAD CONDUCTOR

Summary. The paper presents a theoretical study of the calculation of electric field induced in vicinity of an overhead current carrying conductor. Exact method of the determination of the induced electric field bases on the Fourier transform technique, whereas a simplified method uses the concept of complex ground return plane. As an example the induced electric field under a power line conductor is calculated.

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Ryszard PORADA, Adam GULCZYŃSKI

Politechnika Poznańska

CONTROL OF POWER ELECTRONICS CURRENT SOURCE WITH APPLICATION OF DISCREET REGULATORS

Summary. Traditional methods of analog control for systems working as independent power electronics systems with descrete modulation do not enable to obtain required nowdays high-quality output signals. The article provides general characteristics of classical and modern methods with application of digital regulators in control. It presents algorithms of these regulators and description of possibility of their use to the control with independent power electronics current source. Selected simulation results of such system for different type of reference signals are also included.

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Wojciech MITKOWSKI

AGH - Akademia Górniczo-Hutnicza

ANALYSIS OF NONUNIFORM ELECTRIC LC-LADDER NETWORK

Summary. The paper analyzes spectral properties of heterogeneous LC systems. The LC systems have undamped oscillations. Then we considered the problem of controllability of such systems - observability is a property dual to controllability. The controllable and observable system can be stabilized – that fact is important in practical applications. Normally, the stabilization is done by designing appropriate feedback.

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Krzysztof GÓRECKI, Janusz ZARĘBSKI

Akademia Morska w Gdyni

INFLUENCE OF THE MOUNTING OF A SEMICONDUCTOR DEVICE ON ITS TRANSIENT THERMAL IMPEDANCE

Summary. In the paper some results of investigations of the influence of the manner of mounting semiconductor devices on its transient thermal impedance are presented. The applied by the authors the method of measurements of this parameter is described and some results of measurements of waveforms of the transient thermal impedance of selected types of transistors operating at different mounting conditions are shown. With the use of the authors’ program ESTYM the values of parameters of the model of the transient thermal impedance were estimated. The influence of the manner of mounting manner on the value of these parameters is analysed. Investigations were passed both for devices operating one by one, as and for the analog integrated circuit and transistors situating on the common heat-sink.

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Andrzej ZAWADZKI, Maciej WŁODARCZYK

Politechnika Świętokrzyska w Kielcach

APPLICATION OF FRACTIONAL DIFFERENTIAL CALCULUS USED TO MODELING A CLASS OF NONLINEAR GENERATORS

Summary. Linearization method for nonlinear equation of state by using the geometric transformation of the state variables is shown in the paper. Some elements of Lie algebra was used for the construction of this transformation. All necesary definitions and principles that are required to linearize the nonlinear state equation describing a second-order non-linear generator is shown. Continuous linear fractional system is the result of change of the first order differential operator on the order of the fractional operator in the linearized equation. It was solved by using matrix Mittag-Leffler functions. A comparison of the results with the solution of equations of the first order is made. The results are shown in diagrams. The calculations were made for the lower and higher than first orders of equations.

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Andrzej KUKIEŁKA

Politechnika Śląska w Gliwicach

DUAL SIMILARITY OF VOLTAGE TO CURRENT AND CURRENT TO VOLTAGE TRANSFER FUNCTION OF HYBRID ACTIVE TWO-PORTS WITH CONVERSION

Summary. Dual active two-port networks in hybrid connection are discussed and their voltage to current (M) and current to voltage (N) transfer functions for parallel to serial (and serial to parallel) connections are determined. Relations between transformation of their internal structures and kinds of two-port network connections are analyzed. Appropriate use of: dual constant of conversion of internal gain, impedance inversion and overall transfer functions M and N allows to extend the theory of General Principles of Similarity of Electric Networks of Professor Tadeusz Zagajewski.

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Krzysztof SZTYMELSKI, Marian PASKO

Politechnika Śląska w Gliwicach

B-H LOOP MATHEMATICAL MODEL

Summary. In this article the mathematical model of B-H loop has been presented. The formulae describing the B-H loop using the parametric functions and functions B = f(H) have been carried out. Obtained results have been illustrated by an examples including the approximation of B-H loop of real material sample.

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