QuarterlyIssue 2 (222)
Scientific Committee
CONTENTS
Foreword
- Górecki K., Zarębski J., Detka K.: Magnetic materials used in DC-DC converters
- Jankowski P.: Simple models of transmission line in Mathcad enviroments
- Brociek W., Wilanowicz R.: Simulation studies of the supplying system with nonlinear load and filtering copensating devices
- Brock S.: Effect of torque ripple produced by a permanent magnet synchronous motor on the accuracy of the direct drive
- Mynarek P., Kowol M.: Transient thermal analysis for small motors
- Kolańska-Płuska J.: Verification of measurment impedances of height current busdact
- Pruski P., Paszek S.: Calculations of electromechanical eigenvalues based on simulation and measurement instantaneous power waveforms of generating units
- Przytulski A.: HF elektromagnetic wave at the boundary between the air and human body environments
- Walczak J., Stępień R.: Discrete modeling of LFSR registers
Krzysztof GÓRECKI, Janusz ZARĘBSKI
Katedra Elektroniki Morskiej, Akademia Morska w Gdyni
Kalina DETKA
Pomorska Wyższa Szkoła Nauk Stosowanych w Gdyni
MAGNETIC MATERIALS USED IN DC-DC CONVERTERS
Summary. In the paper the properties of selected magnetic materials used as cores of choking-coils and impulse-transformers are analysed. The differences in the form of most important characteristics of the ferrite, powder and nanocrystalline cores are shown and discussed. The ranges of utilizations of the mentioned cores are pointed and some situations in which each core has an optimum exploitive properties are analyzed.
Piotr JANKOWSKI
Department of Marine Electrical Power Engineering, Gdynia Maritime University
SIMPLE MODELS OF TRANSMISSION LINE IN MATHCAD ENVIROMENTS
Summary. The article presents the possibilities of the Mathcad environment which allow to create simple models of transmission lines. Two models are discussed: the discrete model based on the circumferential model of line treated as a system of L-type four-terminal networks and the model called continuous which implements solution of the telegraphy equations in the quasi-steady state. The article emphasizes the didactic features of the above models, mainly because of the use of the animation possibilities of the Mathcad which allow to easily implement existing analytical solutions also for transients.
Wiesław BROCIEK
Instytut Elektrotechniki Teoretycznej i Systemów Informacyjno-Pomiarowych, Politechnika Warszawska
Robert WILANOWICZ
Instytut Systemów Transportowych i Elektrotechniki, Uniwersytet Technologiczno-
Humanistyczny im. Kazimierza Pułaskiego
w Radomiu
SIMULATION STUDIES OF THE SUPPLYING SUSTEM WITH NONLINEAR LOAD AND FILTERING COPENSATING DEVICES
Summary. The paper presents the simulation results concerning the cooperation of the filtering compensating device and the nonlinear load of high power the inductive character. The load is supplied from the network of the middle voltage of the known short circuit power. The paper will determine the currents and voltages of the succeeding harmonics in percentage of the fundamental harmonic at application of the single and double section filter, at different values of its quality D. The nonlinear load may be characterized be constant or varying parameters. The results of simulation may be used in practice to determine the degree of deformation of the voltage in the power system.
Stefan BROCK
Instytut Automatyki i Inżynierii Informatycznej, Politechnika Poznańska
EFFECT OF TORQUE RIPPLE PRODUCED BY A PERMANENT MAGNET SYNCHRONOUS MOTOR ON THE ACCURACY OF THE DIRECT DRIVE
Summary. In the paper the influence of the electromagnetic torque ripple produced by a permanent magnets synchronous motor for precision direct drive operation is analyzed. In the first part the practical method of identifying those components of the motor torque is proposed. Tests are carried out in a closed loop control system. The next part presents a method of compensation effectively reduces the ripple of the speed. In the compensation block is calculated the additional reference component of the current in the q-axis.
Piotr MYNAREK, Marcin KOWOL
Instytut Układów Elektromechanicznych i Elektroniki Przemysłowej, Politechnika Opolska
TRANSIENT THERMAL ANALYSIS FOR SMALL MOTORS
Summary. The work describes a method of thermal calculations for an induction motor. Thermal model of the analyzed motor was built based on the thermal network method and was implemented in PLECS package. A model of motor presented in the paper allows to determine temperatures of particular components of the machine. Simulations were performed for different motor operating states Simulation results, were verified by measurements performed on the physical model of the motor. Temperature measurements were made with use of LabView environment.
Joanna KOLAŃSKA-PŁUSKA
Instytut Układów Elektromechanicznych i Elektroniki Przemysłowej, Politechnika Opolska
VERIFICATION OF MEASURMENT IMPEDANCES OF HEIGHT CURRENT BUSDACT
Summary. The designation of inductance of their own and their mutual and impedance height current busdact leading electricity to the coil is a process complex. In many cases the omission of impedance track replacement height current busdact is possible. In the case of toughening conduction internal surfaces of steel tubes using actuator cables internal impedance height current busdact omission of the track, however, is too much simplification and may result in the poor choice of a power source and the whole system parameters. In this work shows the results of impedance measurement system input busdact – internal inductor designated as the quotient of the values complex voltage to the current. Measurement has been carried out, at the input terminals of the track grouped with internal inductor and at the terminals of the same actuator cables. The results obtained resistance and inductance was compared with the values obtained in the FEMM.
Piotr PRUSKI, Stefan PASZEK
Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach
CALCULATIONS OF ELECTROMECHANICAL EIGENVALUES BASED ON SIMULATION AND MEASUREMENT INSTANTANEOUS POWER WAVEFORMS OF GENERATING UNITS
Summary. The paper presents the results of calculating the eigenvalues (associated with electromechanical phenomena) of the state matrix of the Polish National Power System model on the basis of analysis of the instantaneous power disturbance waveforms of generating units in Power Plant Łaziska. Calculations of the eigenvalues were carried out by approximating the instantaneous power deviation waveforms with the waveforms being a superposition of the modal components associated with the searched eigenvalues and their participation factors. A hybrid algorithm consisting of a genetic and a gradient algorithms was used for calculations Simulated and measurement instantaneous power waveforms were used in investigations.
Andrzej PRZYTULSKI
Instytut Układów Elektromechanicznych i Elektroniki Przemysłowej, Politechnika Opolska
HF ELEKTROMAGNETIC WAVE AT THE BOUNDARY BETWEEN THE AIR AND HUMAN BODY ENVIROMENTS
Summary. The behaviour of a HF plane harmonic wave at the boundary between the air and human body for the case of perpendicular incidence has been studied in the paper. The aim of the performed research was to estimate parts of the wave and energy absorbed by the body in percentage terms, since the articles dealing with the harmful effects of HF electromagnetic fields on the human body usually assumed „silently” that they penetrated the body in one hundred per cent.
Janusz WALCZAK, Rafał STĘPIEŃ
Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach
DISCRETE MODELING OF LFSR REGISTERS
Summary. This paper shows a method of describing pseudo random signal generators with LFSR registers in discrete circuits and signal terminology. The generalized equations of the LFSR register and their creation are shown. The LFSR structures based on proposed equations are also shown.