Krzysztof BADYDA, Janusz LEWANDOWSKI
Polish power industry based on coal - conditions of its development
Energetyka 2008, nr 3, s. 167 Inevitable challenges awaiting hard coal based Polish power industry in the perspective of forthcoming years are: continuation of intensive investing in environment protection installations, replacement of the decapitalized production assets with new ones i.e. reproduction investments, ensuring fuel supply adequate to planned production needs resulting from accomplishment of production stabilization plans and stabilization on present level of hard and brown coal consumption.
Housing near power transmission lines
Energetyka 2008, nr 3, s. 177
The high development of housing has been observed lately. This development requires areas for buildings. These areas very often are crossed by power transmission lines. Therefore there are problems with placement of buildings and other objects near lines. The proper insulation distances should be kept and electric field intensities should be lower than 1 kV/m and magnetic field intensities shoul be lower than 60 A/m. The paper presents analysis of these problems. Condition E < 1 kV/m is mostly more restrictive than insulation distance.
Andrzej SOWA, Krzysztof WINCENCIK
Protection against threats caused by surge currents during direct lightning strikes to wind turbines
Energetyka 2008, nr 3, s. 179
The problem of lightning flash damage to wind turbine has become more pronounced with the upward trend unit capacities, necessitating increasingly taller structures to accommodate larger blade lengths. Therefore, effective lightning protection methods are required. This paper presents the information about lightning damages observation and different methods of measurements these threats. These results help to prepare lightning protection of structure
and protection of signal or power supply system against lightning overvoltages.
Technological conditions of ships power supply system tests
Energetyka 2008, nr 3, s. 181
Paper presents technological aspects of acceptance tests in view of voltage quality and reliability. Power supply system of con-ro vessel B201 was shown as an example of modern ship's solution fulfilling class requirements. Production technology determinants and input data for creating and conducting dock tests and sea trials programs have been determined.
Creation of nanopolymers in epoxy resin-copper sulfide set-up
Energetyka 2008, nr 3, s. 183
One of barriers stopping nanocomposites from wide applications is problem
of preparing the filler with high level of granularity. The paper presents easy
way of new material's production, which is nanocomposite of epoxy resin and copper sulfide, created during the process of resin's hardening. As a base for copper sulfide aminepolysulfide and copper benzoate were used. Conditions necessary for sustained suspension formation with submicrometric sizes of particles were found out and new application of the new material were given.
Edward CADLER, Kazimierz HERLENDER
Electromagnetic compatibility and low voltage non-linear receivers
Energetyka 2008, nr 3, s. 184
Technological progress in recent times caused increase in the amount of power electronic receivers and low power receivers fed from impulse converters. Especially negative influence on the level of electromagnetic disturbances have installations of non-linear current-voltage characteristics which are the current source of harmonics. All these effects have big influence on electric energy quality.
Adam GUBAŃSKI, Jan ZIAJA
Thermally stimulated currents of Zn-Bi-O thin film varistors
Energetyka 2008, nr 3, s. 188
Ceramic varistors based on zinc oxide have exellent properties as protection devices used in power industry.. In this article performace of micro-devices having varistor-type current-voltage characteristics with low breakdown voltage is reported.The thermally stimulated depolarization current (TSC) technique was used to study the dielectric relaxation of the Zn-Bi-O thin film arresters. Surface varistors layers were prepared by r.f. magnetron sputtering on Cu support.
Two-core phase shifting boost transformers in anaspect of making computations of temperatures and allowable emergency loading currents
Energetyka 2008, nr 3, s. 190
The problem of working out of the numerical program to estimate oil and copper windings temperatures and load ability of phase shifting transformers (PST) is considered in this paper. Moreover, a short comparison of power transformers and PSTs, the electrical diagram and equations used to calculate winding currents are also presented. The calculations of temperatures and load ability of PSTs are more complicated than for power transformers, mainly because the estimation of winding currents is impossible without using trigonometric functions. Additionally, some of PSTs are designed as a two-tank unit with common cooling system or independent one. In case of independent cooling systems of two-tank PST, the unit should be considered as one unit for electrical calculations and separate units for thermal calculations.
Problems of storing from renewable sources the electric energy
Energetyka 2008, nr 3, s. 193
The renewable sources of energy have both their advantages how and defect. Basic advantage of such sources how the energy of wind or else general their accessibility is the sunny radiation as well as the unrestricted supplies.We for carriers these kinds of energy need not pay. Basic problem however periodical accessibility of these carriers is. The sunny radiation reaches to us in day only, and this under condition of lack of cloudiness, however the wind is not always it blows with sufficient required through generator power. In other hands, these forms of energy are accessible in suitable time not always. It comes into being so to make with produced in time energy problem, what, when there is no sale, np. on her during windy night. The different ways of storing the energy exist np. for help of whirling masses, magnetical field, fuel cells, water reservoirs and gas, the battery of batteries etc. Exists however the problem, with what criteria to act near selection of arrangement storing in concrete case the energy.
Magdalena BORGOSZ-KOCZWARA, Kazimierz HERLENDER
Power security and renewable energy sources
Energetyka 2008, nr 3, s. 194
The most of renewable energy systems are distracted generation systems. These systems can have positive influence on reliability of supply, by faster rebuilding power network after failure, can improve reliability of supply to all kinds of customers and can reduce depth of voltage collapse. It can't be made assumption that renewable energy sources automatically improve reliability of power network but it must be taken necessary activities to assure of power security of local power systems.
Investigation of electrical discharges development in transformer oil using photo-optical methods
Energetyka 2008, nr 3, s. 197
Preliminary results of investigations on electrical discharge developement in transformer oil using photo-optical methods are presented in this paper. The photographs of discharges were taken out together with time resolved pattern of the light emmited by their channels.
Janusz MICHALSKI, Kazimierz ZASADZIŃSKI
Evolution of railway infrastructure implies modernization of traction system
Energetyka 2008, nr 3, s. 199
This article presents influence of the train speed increase on construction changes of section insulators, investigation results of tension insulators with modyfied EPDM housing after 8 years operation on the traction system located in hard environment
Artur ROJEK, Wiesław MAJEWSKI
Construction and materials of railway overhead contact line (OCL)
Energetyka 2008, nr 3, s. 201
The paper presents constructional foundations and requirements of OCL construction. Differences between OCL and 3-phase power line were accentuated. There are given parameters of the new type of OCL designed for high speeds. Constructions and materials of elements of OCL are talked over.
Paweł KIEŁKOWSKI, Grzegorz CYGANEK
Application of cold shrinkable technology in MV cable accessories
Energetyka 2008, nr 3, s. 204
Development of cable joints technology caused evolution not only in the way of attitude to cable solutions but also the evolution of insulation materials used for cable joints and endings. Thanks to their properties cable boxes and heads have now wider range of application, they are more resistant and simpler in assembling and operation. Market solutions existing for the last few years outrun all competition in the field of their possibilities.
Comparison of trends in financing and implementations of material
engineering and electrotechnologies in polish and german economy
Energetyka 2008, nr 3, s. 206
The Authors compared the problems of research and organisation of technological implementations in material engineering and electrotechnology in Poland and Germany.
Modern installation for desulphurization of flue gases with the use of ammonia semi-dry method
Energetyka 2008, nr 3, s. 209
The faster is chemical reaction the bigger is degree of reacting substances fineness. Increase of reaction speed causes shortening of sorbent-flue gases contact time and enables diminishing of installation overall dimensions. Ammonia water is reacting substance in the method described. It is sprayed acquiring the form of dry mist with the help of atomizers. Given are their features and types.
Notes on contracts applied to electric power supplies
Energetyka 2008, nr 3, s. 216
Given are basic types of contracts which are obligatory according to the Energy Law and concerning selling, transmission and distribution of electric energy. Described is procedure of contract changing. Specified are illicit contractual clauses.
Microbial fuel cells processing organic sewage directly into electricity
Energetyka 2008, nr 3, s. 220
Described is a microbial fuel cell principle of operation in which bacteria are biocatalysts in direct conversion of organic substance into electricity. Organic substances used in the process of microbial fuel cells electricity production can be carbohydrates, municipal wastes and sea sediments as well as animal, agriculture and industrial wastes.