QuarterlyIssue 2-3 (230-231)
Scientific Committee
CONTENTS
- Lesław LACROIX: New power units based on fuel coal and gas with power over 400 MW their role in national electric power system
- Paweł KUBEK: Analysis methods of overhead electrical conductors in terms of thermal and mechanical criterias
- Tomasz RUSEK: SF6 economy for electrical installations – selected legal aspects
- Kamil BARCZAK: Light depolarizer for optical fiber current sensor with external transformation
- Sabina DREWNIAK, Tadeusz PUSTELNY, Włodzimierz STRUPIŃSKI, Iwona PASTERNAK, Zbigniew OPILSKI: Methods of graphene characterization using in resistive sensor’s systems
- Aneta OLSZEWSKA: Location of partial discharges in power oil transformers using acoustic emission method and ADP descriptor
- Marcin KASPRZAK, Piotr LEGUTKO, Kamil KIEREPKA: The comparison of L-C and L-LC matching circuts for class D 1,5 KW/300 KHZ inverter
- Adam PILŚNIAK, Lesław TOPÓR-KAMIŃSKI, Piotr HOLAJN, Janusz GUZIK, Aleksander KUMOR: Influence of crest factor on errors of the RMS-DC converter
- Andrzej SIKORA, Barbara KULESZ: Frequency response method in diagnosing condition of insulation system in electrical machines
- Romuald GRZENIK: Electric motor with hibrid excitation
- Damian BIJAK, Grzegorz KŁAPYTA: Inverted pendulum – design of mechanics using autodesk inventor and MATLAB/SIMULINK
- Grzegorz SZERSZEŃ: The low noise optimum preamplifier capable for cooperation with measuring 8AE-PD system
Lesław LACROIX
Politechnika Śląska w Gliwicach
NEW POWER UNITS BASED ON FUEL COAL AND GAS WITH POWER OVER 400 MW, THEIR ROLE IN NATIONAL ELECTRIC POWER SYSTEM
Summary. This article describes the construction and the plans for the construction of power units based on carbon fuel - coal and lignite and the gaseous fuel. The main objective of these investments is to replace the withdrawn blocks to be able to maintain a balance of power system with adequate surplus installed capacity. The reasons for the withdrawal of a certain amount of existing units are described later in the article. The article briefly describes the new technology of steam generation in boilers of the so-called. supercritical parameters, which increase significantly the efficiency of coal-fired units in relation to the technology currently used. The article presents a certain threat to the operation units on the level of power above 850MW at the time of the so-called (off peak) valleys of daily load of the power system The article also mentioned about the IED European Directive, which requires the limitation of emissions of harmful substances (gases) into the atmosphere, mainly it is a harmful gases: as sulfur dioxide or nitrogen multioxides and carbon dioxide.
Paweł KUBEK
Politechnika Śląska w Gliwicach
ANALYSIS METHODS OF OVERHEAD ELECTRICAL CONDUCTORS IN TERMS OF THERMAL AND MECHANICAL CRITERIAS
Summary. A thermal modernization allows to increase the thermal rating of the existing lines. Especially it concerns the older overhead lines designed for the +40°C temperature conductor limit. This paper presents reconductoring the attractive method of existing lines thermal modernization. Article provides an overview of issues related to the selection of HTLS conductor for thermal upgrading of existing overhead transmission lines. Some aspects related to the extension of the thermal and mechanical models used so far for analysis of HTLS conductors are presented in the paper.
Tomasz RUSEK
Politechnika Śląska w Gliwicach
SF6 ECONOMY FOR ELECTRICAL INSTALLATIONS – SELECTED LEGAL ASPECTS
Summary. The article presents some aspects related to the management of SF6 in electrical engineering installations. Briefly discussed possible in the flow of gas to the environment in the context of the greenhouse effect. In the next part presents selected aspects of SF6 economy, especially in the field of condition monitoring of gas purity, decay products, possible defects and leaks. The whole article was supplemented with a brief overview of basic legal acts, both international and domestic, relating to and connected with the SF6 economy.
Kamil BARCZAK
Politechnika Śląska w Gliwicach
LIGHT DEPOLARIZER FOR OPTICAL FIBER CURRENT SENSOR WITH EXTERNAL TRANSFORMATION
Summary. A fiber optic sensor with external processing requires supply of light to its head via an optical fiber. Laser diodes are applied as a source of light, in order to obtain a high-power light beam. However, this solution has a major disadvantage: a light beam at an input of the sensor head is linearly polarized. The direction of polarization changes constantly because the optical fiber is prone to twisting and deformation. The result is a varying intensity of light that passes an input polarizer. Author of this article proposes a solution to this issue depolarizing the input light beam by means of a system of fiber optic couplers. The main goal of presented work is optimization of this system.
Sabina DREWNIAK, Tadeusz PUSTELNY, Zbigniew OPILSKI
Politechnika Śląska w Gliwicach
Włodzimierz STRUPIŃSKI, Iwona PASTERNAK
Zakład Epitaksji Związków Półprzewodnikowych, Instytut Technologii Materiałów Elektronicznych w Warszawie
METHODS OF GRAPHENE CHARACTERIZATION USING IN RESISTIVE SENSOR’S SYSTEMS
Summary. The environmental pollution entails the monitoring of selected gas atmospheres. In this paper, the results of characterization the thin film resistance sensor (characterization of grapheme - sensitive layer) will be presented. Such sensor can detect the hydrogen and nitrogen dioxide in the atmosphere of synthetic air at a very low level. There will be presented, among others, the images of topography and raman’s spectras of the structures. There will be analyzed changes which occure in the structure (observed at the Raman’s spectra) due to its contact with the atmosphere containing 3% hydrogen.
Aneta OLSZEWSKA
Politechnika Śląska w Gliwicach
LOCATION OF PARTIAL DISCHARGES IN POWER OIL TRANSFORMERS USING ACOUSTIC EMISSION METHOD AND ADP DESCRIPTOR
Summary. The study presents results of the location of partial discharge (PD) sources in selected power oil transformer. This location has been carried out by the method of degree of advancement of acoustic emission (AE) signals, the method is based on the calculation of specially defined descriptors, designation of maps of these descriptors on lateral walls of transformers in different frequency bands, and then the analysis of AE signals recorded in areas with a greater degree of advancement of the signals on the map of the descriptor. In this article the location of PD sources using ADP descriptor is presented.
Marcin KASPRZAK, Piotr LEGUTKO
Politechnika Śląska w Gliwicach
Kamil KIEREPKA
Student, Politechnika Śląska w Gliwicach
THE COMPARISON OF L-C AND L-LC MATCHING CIRCUTS FOR CLASS D 1,5 kW/300 kHz INVERTER
Summary. Two load matching circuits of Class D inverter for induction heating applications are presented in the paper: serial resonant L-C and series-parallel L-LC. The theory of L-LC is presented too. The new reconfiguration method of L-C into L-LC based on the same resonant capacitor is proposed. Both matching circuits are compared based on measurements of 1,5 kW inverter and applying the same heating coil and load. The conclusion is, that main advantages of L-LC over conventional L-C is lower matching transformer current levels and lower transformer turns ratio.
Adam PILŚNIAK, Lesław TOPÓR-KAMIŃSKI, Piotr HOLAJN, Janusz GUZIK, Aleksander KUMOR
Politechnika Śląska w Gliwicach
INFLUENCE OF CREST FACTOR ON ERRORS OF THE RMS-DC CONVERTER
Summary. Usually a maximum error is defined in data sheets of True RMS analog converters. It includes two components. One of them is a multiplication error which depends of actual voltage value. The second is an additional error, caused by a noise and offset voltage.
Andrzej SIKORA, Barbara KULESZ
Politechnika Śląska w Gliwicach
FREQUENCY RESPONSE METHOD IN DIAGNOSING CONDITION OF INSULATION SYSTEM IN ELECTRICAL MACHINES
Summary. The paper presents problem of accelerated insulation aging in electrical machine cooperating with power electronics converter. The method of assessing insulation’s condition based on generation of ac voltage during breaking dc current flowing through the circuit is described. Examples of ac voltage wave generated in different insulation systems are shown.
Romuald GRZENIK
Politechnika Śląska w Gliwicach
ELECTRIC MOTOR WITH HIBRID EXCITATION
Summary. Conception of brushless motor with hybrid excitation has been presented in the paper. The poles are excited with permanent magnets and electromagnetically. Field calculations for motor with 3 pole pairs have been conducted (two pairs excited with permanent magnets and one pair excited electromagnetically). The calculations have been carried out for rated load and for overload conditions (load equal to twice its rated value). The calculations show that in the second control zone motor may achieve twofold change in rotational speed
Damian BIJAK, Grzegorz KŁAPYTA
Politechnika Śląska w Gliwicach
INVERTED PENDULUM – DESIGN OF MECHANICS USING AUTODESK INVENTOR AND MATLAB/SIMULINK
Summary. The inverted pendulum is a physical device arranged to provide a suspended vertical position stabilization of devices with the center of gravity located above the drive system. Studies of this type of equipment led to the design and development of various types of transport platforms. A popular vehicle, which is a kind of inverted physical pendulum, is "Segway" - Human Transporter. Its two-wheeled chassis easily overcomes bumps in the road while driving. The goal of the article is to present the design of the mechanical part of the demonstrative physical pendulum including its drive system. The following chapters present the mechanical design of the pendulum, the selection of device components: constructional components, drive with the powertrain, sensors. The paper presents also selected 3D models prepared for the simulation of dynamics of the pendulum, the Matlab-Simulink implementation of its mathematical model and chosen results of simulations. This paper summarize the engineering project realised in the Chair of Mechatronics at SUT Gliwice.
Grzegorz SZERSZEŃ
Politechnika Śląska w Gliwicach
THE LOW NOISE OPTIMUM PREAMPLIFIER CAPABLE FOR COOPERATION WITH MEASURING 8AE-PD SYSTEM
Summary. The subject of the article concerns investigations and conceptional works realized by scientific workers from Department of Optoelectronics Silesian University of Technology aimed at design and construct a low noise preamplifier assigned for collaboration with computer measuring system 8EA-PD which serves for detection and location of partial discharges by means of acoustic method within power transformers. The principal purpose of works presented in the article was optimization of parameters of the measuring preamplifier which is used at present and built on a base of well-known INA110KP integrated circuit.The publication contains investigation results which point out possibility to construct a new preamplifier with parameters considerably better than the predecessor. Chosen constructional solutions, based on the latest self-contained measuring preamplifiers, worked out at 2012 year by the firm Analog Devices, have been presented.The result of carried out works was construction of entirely functional voltage preamplifier assigned for collaboration with computer measuring 8EA-PD system as well as with measuring sensors of WD series and D9241A. It offers in its basic version amplification of 70 dB (regulated step by step) and transfer band from 15 kHz to 1.3 MHz.