QuarterlyIssue 1 (237)

#### Scientific Committee

**CONTENTS**

Foreword

- Mariusz TROJNAR: Application of the Multisim program in analysis of the transmission lines
- Mariusz TROJNAR: Computer aided analysis of transient states in linear circuits
- Przemysław PTAK, Krzysztof GÓRECKI, Janusz ZARĘBSKI: Power supply circuits used in led lamps
- Wojciech MITKOWSKI: Control of DC motor with a time delay controller
- Jerzy JAKUBOWSKI, Janusz LEWANDOWSKI, Agnieszka JAKUBOWSKA: Turn short circuit in synchronous and asynchronous motors
- Marcin SOWA: Simple C# Classes for fast multivariate polynomial symbolic computation – part I: implementation details
- Marcin SOWA: Simple C# Classes for fast multivariate polynomial symbolic computation – part II: analysis of numerical efficiency
- Marcin SOWA: Simple C# Classes for fast multivariate polynomial symbolic computation – part III: polynomial multiplication algorithm and its efficiency
- Sebastian BARTEL: Review of selected designs and conception of electromagnetic pulsating blood flow pump and its control system
- Maciej PILOT: Analysis of magnetic fields in unconventional driving systems with permanent magnets

#### Mariusz TROJNAR

###### Rzeszów University of Technology

#### APPLICATION OF THE MULTISIM PROGRAM IN ANALYSIS OF THE TRANSMISSION LINES

**Summary**. The paper describes the possibilities of Multisim program in the analysis of transmission lines. It also presents examples of lossless and lossy transmission line simulation in steady-state and transient conditions, which have been carried out by means of this program. Results of circuit simulation in Multisim program are consistent with results of simulation in PSpice program.

#### Mariusz TROJNAR

###### Rzeszów University of Technology

#### COMPUTER AIDED ANALYSIS OF TRANSIENT STATES IN LINEAR CIRCUITS

**Summary**. The article presents examples of application of chosen computer programs in the analysis of transient states in linear circuits. Analytical solution of two circuits (calculation of currents and voltage) has been presented on the basis of classical method and Laplace transform method. The circuits were then subjected to computer simulation in Multisim and PSpice programs. Moreover, Mathcad program was used to solve one of the calculation examples. Each of the computer programs mentioned can be successfully applied to analysis of transient states in electrical circuits, both for educational purposes and in scientific research.

#### Przemysław PTAK, Krzysztof GÓRECKI, Janusz ZARĘBSKI

###### Gdynia Maritime University

#### POWER SUPPLY CIRCUITS USED IN LED LAMPS

**Summary**. Load resistance and line voltage impact on electric parameters of power supply circuits used in LED lamps are discussed in this paper. Investigations were performed for two power supplies typically used in CLA25 and CLA60 lamps offered by OSRAM Semiconductor. Measurements were performed for load resistance ranging from 10 Ω to 10 kΩ and for the alternating input voltage of line frequency and RMS value ranging from about 10 V to 230 V. The impact of power supplies of LED lamps on deformation of the current drawn from the network was also analysed.

#### Wojciech MITKOWSKI

###### AGH University of Science and Technology, KRAKÓW

#### CONTROL OF DC MOTOR WITH A TIME DELAY CONTROLLER

**Summary**. The electric drive is and will probably continue to be of primary importance in engineering and technical sciences. In this work a particular issue of controlling dc motor with the time-delay controller is discussed. The time delays in the circuit emerge e.g. when the object is controlled via a great distance (space trips for instance - space ships are controlled from the Earth). The original achievement of this work is determination of the stability range of appropriate time-delay control circuit.

#### Jerzy JAKUBOWSKI^{1}, Janusz LEWANDOWSKI^{1,2}, Agnieszka JAKUBOWSKA^{3}

^{1} Ośrodek Pomiarów i Automatyki Przemysłu Węglowego SA w Zabrzu

^{2} Katedra Mechaniki i Podstaw Konstrukcji Maszyn, Wydział Mechaniczny, Politechnika Opolska

^{3} Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach

#### TURN SHORT CIRCUIT IN SYNCHRONOUS AND ASYNCHRONOUS MOTORS

**Summary**. The paper presents comments and observations resulting from research of electrical power devices. Drive motors are essential elements of the processing chain in industrial plants. Synchronous and asynchronous motors are about the most important group among the drive motors, due to their power properties and the simplicity of power and control systems. During failures of synchronous and asynchronous machines, a burnout of coil turns takes place. RMS values of phase currents during the short-circuit of turn do not show a significant asymmetry, which consequently results in a lack of effective protection against short-circuit of individual turns. The authors propose a solution of this issue based upon the phase angle control of different currents. The phenomenon of current phase angle asymmetry occurring during turn short-circuit has been utilized.

#### Marcin SOWA

###### Silesian University of Technology, Gliwice

#### SIMPLE C# CLASSES FOR FAST MULTIVARIATE POLYNOMIAL SYMBOLIC COMPUTATION – PART I: IMPLEMENTATION DETAILS

**Summary**. The paper deals with a lightweight C# implementation that allows to perform symbolic computation on multivariate polynomials in expanded forms. The classes called SPoly and SMono (which represent the expressions) are explained along with their limitations. Furthermore a few remarks are made on the usefulness of methods working as += and –= operators. A further analysis of the implementation is given in parts II and III of the paper.

#### Marcin SOWA

###### Silesian University of Technology, Gliwice

#### SIMPLE C# CLASSES FOR FAST MULTIVARIATE POLYNOMIAL SYMBOLIC COMPUTATION – PART II: ANALYSIS OF NUMERICAL EFFICIENCY

**Summary**. In part I of the paper the implementation details of a lightweight C# implementation of symbolic computation of multivariate polynomials has been presented. The current part presents the results of an analysis of the numerical efficiency. The symbolic addition/subtraction, differentiation and definite integration operations are studied. The multiplication and exponentiation operators are discussed in part III.

#### Marcin SOWA

###### Silesian University of Technology, Gliwice

#### SIMPLE C# CLASSES FOR FAST MULTIVARIATE POLYNOMIAL SYMBOLIC COMPUTATION – PART III: POLYNOMIAL MULTIPLICATION ALGORITHM AND ITS EFFICIENCY

**Summary**. Part I of the paper represented the implementation details of a lightweight C# implementation of symbolic computation of multivariate polynomials. Part II represented the results of an analysis of the numerical efficiency. The current part discusses the multiplication and exponentiation operations. An original algorithm for sparse multivariate polynomial multiplication is proposed. An analysis on polynomial exponentiation is also performed.

#### Sebastian BARTEL

###### Silesian University of Technology, Gliwice

#### REVIEW OF SELECTED DESIGNS AND CONCEPTION OF ELECTROMAGNETIC PULSATING BLOOD FLOW PUMP AND ITS CONTROL SYSTEM

**Summary**. Model of electromagnetically driven pulsating micropump and control system of the drive are presented in this paper. The task of the micropump is to pump liquid (blood) in accordance with natural cycle of the human heart. Two classical examples of rotary assist pumps (LVAD type) and two examples of fully artificial heart designs are presented in section II (Devices assisting performance of left ventricle and fully artificial hearts). Spatial design and description of the proposed innovative drive design are presented in section III (Design of innovative pulsating micropump with electromagnetic drive). Field analysis of this devised novel micropump drive for two proposed modes of operation is described in section IV (Field model of pulsating electromagnetically driven micropump). On the basis of analysis results, the pros and cons of the proposed design of micropump drive are discussed.

#### Maciej PILOT

###### Silesian University of Technology, Gliwice

#### ANALYSIS OF MAGNETIC FIELDS IN UNCONVENTIONAL DRIVING SYSTEMS WITH PERMANENT MAGNETS

**Summary**. The article presents analysis of magnetic fields in unconventional driving systems with permanent magnets. Muammer Yildiz patent (No. WO 2009/019001 A2 [1] ) and Claus Turtur publications [2] constitute the basis for the designs. The analysis is based on FEM static simulations, which do not take into account either interaction dynamics between the objects or propagation speed of interacting fields. The analysis focuses on the changes of torque turning driving system rotor as a function of rotor angle and excitation current.