QuarterlyIssue 4 (220)
Scientific Committee
CONTENTS
Foreword
- Jerzy BARANOWSKI: Nonlinear velocity observer for separately excited DC motor
- Marcin MACIĄŻEK, Dariusz GRABOWSKI, Michał LEWANDOWSKI: Analysis of compensation efficiency carried out by means of an active power filter
- Mariusz NAJGEBAUER, Jan SZCZYGŁOWSKI: Magnetic composites in electric machines
- Paweł JABŁOŃSKI: Approximate BEM analysis of thin conductive shell in static electroconductive field
- Paweł JABŁOŃSKI: Approximate BEM analysis of thin electromagnetic shield
- Piotr GACKOWSKI: Analysis of selected environmental conditions affecting safety enter LNG gas carriers to terminal LNG
- Piotr PRUSKI, Stefan PASZEK: Modal analysis of instantaneous power disturbance waveforms in the polish national power system
- Roman MUSZYŃSKI: Requirements and structure of the inverter for adjustable AC drives
- Zbigniew GORYCA, Mariusz MALINOWSKI, Artur PAKOSZ: Minimalization of cogging torque in the multipole machine with permanent magnet
Jerzy BARANOWSKI
Akademia Górniczo-Hutnicza, Katedra Elektrotechniki i Elektroenergetyki
NONLINEAR VELOCITY OBSERVER FOR SEPARATELY EXCITED DC MOTOR
Summary. In this paper an observer for separately excited DC motor is presented. This observer is constructed with an application of nonlinear coordinate change which allows obtaining linear estimation error dynamics. Operation of the observer is illustrated with numerical experiments.
Marcin MACIĄŻEK, Dariusz GRABOWSKI, Michał LEWANDOWSKI
Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach
ANALYSIS OF COMPENSATION EFFICIENCY CARRIED OUT BY MEANS OF AN ACTIVE POWER FILTER
Summary. A frequency model of an active power filter as well as its simulation investigation in Matlab/Simulink for dq control algorithm and a sample test system have been developed in the paper. As a result the quality of current compensation for selected harmonics as a function of switching frequency and load power has been determined.
Mariusz NAJGEBAUER, Jan SZCZYGŁOWSKI
Instytut Elektroenergetyki, Politechnika Częstochowska
MAGNETIC COMPOSITES IN ELECTRIC MACHINES
Summary. Magnetic composites are produced from magnetic powder bounded by dielectric binders or resins, which makes a dielectric layer on magnetic grains. Magnetic composite materials are more and more often applied in electric machines due to their favorable magnetic and mechanical properties. The paper describes the structure and properties of magnetic composite materials as well as advantages result from their application on magnetic circuits of electric machines.
Paweł JABŁOŃSKI
Electrical Engineering Faculty, Częstochowa University of Technology
APPROXIMATE BEM ANALYSIS OF THIN CONDUCTIVE SHELL IN STATIC ELECTROCONDUCTIVE FIELD
Summary. A method of approximate analysis of a thin conductive shell in static electroconductive field is considered and proposed in the paper. Thin shells almost always lead to problems in numerical calculations. When applying the Boundary Element Method (BEM) to solve equations for a thin shell, two difficulties arise: significant increase of the number of algebraic equations, and the presence of nearly singular integrals. The proposed model avoids them both by using an approximate analytical solution for the shell. Numerical examples confirm its usability.
Paweł JABŁOŃSKI
Electrical Engineering Faculty, Częstochowa University of Technology
APPROXIMATE BEM ANALYSIS OF THIN ELECTROMAGNETIC SHIELD
Summary. A method of approximate analysis of a thin electromagnetic shield is considered and proposed in the paper. Due to presumably small thickness of the shield, its numerical analysis is troublesome. Applying the Boundary Element Method (BEM) to solve equations for a thin shield creates two difficulties: significant increase of the number of algebraic equations, and the presence of nearly singular integrals. The proposed model avoids them both by using an approximate analytical solution for the shield. Numerical examples confirm its usability.
Piotr GACKOWSKI
Katedra Eksploatacji Statku, Akademia Morska w Gdyni
ANALYSIS OF SELECTED ENVIRONMENTAL CONDITIONS AFFECTING SAFETY ENTER LNG GAS CARRIERS TO TERMINAL LNG
Summary. Analysis of major hydro-meteorological parameters, such as ocean currents, winds and waves in the Pomeranian Bay, having the greatest impact on the safety of the LNG gas carriers entering port. Presented of the criteria and weather limits leading to reduce risks associated with poor weather or heavy hydro-meteorological conditions.
Piotr PRUSKI, Stefan PASZEK
Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach
MODAL ANALYSIS OF INSTANTANEOUS POWER DISTURBANCE WAVEFORMS IN THE POLISH NATIONAL POWER SYSTEM
Summary. The paper presents the calculation results of eigenvalues (associated with electromechanical phenomena) of the state matrix of the Polish National Power System model. These results were obtained on the basis of analysis of the instantaneous power disturbance waveforms in particular generating nodes. Calculations of the eigenvalues were carried out by approximating the instantaneous power waveforms with the waveforms being superposition of the modal components of the parameters dependent on the searched eigenvalues and their participation factors. A hybrid algorithm consisting of genetic and gradient algorithms was used for minimisation of the objective function determined by the deviation vector (in particular time instants). Simulated instantaneous power waveforms were used in investigations.
Roman MUSZYŃSKI
Instytut Automatyki i Inżynierii Informatycznej, Politechnika Poznańska
REQUIREMENTS AND STRUCTURE OF THE INVERTER FOR ADJUSTABLE AC DRIVES
Summary. In the paper the structure optimisation problem for voltage source inverter drives with consideration of its reaction on supply network and others important requirements is treated. The standards relating to the current harmonic emission into the network are given. There are determined the ranges of power in which the requirements are fulfilled by the simplest converter structures with DC capacitor or DC filter and the network side choke as well as the cases when the systems with decreased harmonic emission must be used. The problem of power loss and parameter co-ordination is examined on the example of concrete structures. A multi-criterion comparison of different structures is done. The method of system optimisation based on the aggregation of the separate requirements into one generalised criterion by means of special function is presented.
Zbigniew GORYCA
Instytut Automatyki i Telematyki, Politechnika Radomska
Mariusz MALINOWSKI
Instytut Sterowania i Elektroniki Przemysłowej, Politechnika Warszawska
Artur PAKOSZ
Zespół Szkół Elektronicznych, Radom
MINIMALIZATION OF COGGING TORQUE IN THE MULTIPOLE MACHINE WITH PERMANENT MAGNET
Summary. The paper presents the manner of minimization of cogging torque of multi-pole permanent magnets motor. This method has been patented by the author. This method consists in the right choice of the number of rotor's poles and the number of stator's grooves. Simulation results performed in Comsol Multiphisics and measuring results performed in three prototypes have been presented. Obtained results clearly show, that proposed method is the best among all known methods basing on minimization of cogging torque.