Sixty Years of Silesian Technical University (1945-2005). First Hard Years
Energetyka 2005, No. 12, p. 829
NOWAK-GAJEWSKA M., KANIA A.
Use of Thermovision in Diagnosis of Overvoltage Limiters
Energetyka 2005, No. 12, p. 835, 4 figs, 3 tabs
Thermovision diagnosis of lightning arresters with use of possibilities of modern thermovision systems can be treated as a supplement to traditional measurements and in the case of modern overvoltage limiters, as an essential method used together with measurement method of components of the leakage current. The method discussed in the paper is used at all voltage levels without regard whether it is a lightning arrester or an overvoltage limiter, as well as without regard to the kind of the insulation cover. Occurring explosions of lightning arresters and overvoltage limiters force their more frequent inspection in order to assure faultless operation of the power system and the safety for the operation staff.
BUJKO J., HALAWA T
How to Reduce Participation Costs of Power Units in Automatic Power and Frequency Control
Energetyka 2005, No. 12, p. 843 (IASE Bulletin p. 1), 4 figs, 12 refs
The paper provides estimated costs shared by power units of thermal power stations in Load-Frequency Control (LFC). An algorithm for determining short-term variations of the P action gained in central governor of automatic power and frequency control (CG-LFC) in order to accelerate the return of larger control errors G(t) to the zone of normal variations is given. Maintaining the signal in this zone for extended time influences the reduction of costs shared by power unit in LFC. This would also enable a function of automatic release of intervention power from generating units with Y1i signal to be introduced into CG-LFC system when rapid increase of G(t) signal occurs.
Electricity Market Reform in Europe
Energetyka 2005, No. 12, p. 850 (IASE Bulletin p. 8), 8 refs
The process of market transformations in accordance with EC Electricity and Gas Directives has varied widely across the EU Member States, offering the opportunity of learning from the various experiences. In the paper are presented main topics of joint SESSA-CMI Conference "Refining Market Design" (Cambridge, UK, 2004), focused on examining the performance of various market paradigm in Europe.
BORGOSZ-KOCZWARA M., STAWSKI P.
Promotion Centre for Innovations in Power Industry at Lower Silesia
Energetyka 2005, No. 12, p. 854 (IASE Bulletin p. 12), 1 fig.
In October 2005 there was formed Promotion Centre for Innovations in Power Industry called CEPRIN, which was situated at Institute of Power Systems Automation in Wrocław. Forming the Centre is partly-financed from EU Structural Funds within the European Social Funds and within the Integrated Operational Programme for Regional Development. The main objective of the Centre is the promotion of problems referred to power industry innovations and promotion of local power engineering. A success of the Centre activity depends on creation of a platform of the co-operation between leading local power companies, science centres and local governments.
BROSZKIEWICZ-SUWAJ E., MAKAGON A., WERON A.
Electricity Option Pricing. Black Model Versus HJM Model
Energetyka 2005, No. 12, p. 855 (IASE Bulletin p. 13), 6 figs, 8 tabs, 5 refs
A specific feature of the energy market is a significant contradiction between high daily prices volatility and possibility to forecast these prices. High volatility of energy prices forces producers and large consumers of energy to protect themselves against losses. The future markets provides needed tools (future contracts and options) for building secure strategies of risk management. In this paper two models for pricing the electricity options are discussed. The theoretical results are calibrated to the data achieved from the European Energy Exchange EEX.
KOZŁOWSKI M., MISIOREK A.
Earnings at Risk Approach to Energy Demand Prediction
Energetyka 2005, No. 12, p. 860 (IASE Bulletin p. 18), 2 figs, 2 tabs, 9 refs
In the paper three different methods of prediction of energy demand are compared. The usefulness of the models using popular EaR (Earnings at Risk) risk measure is verified.
BAŁUKA G., BŁASIAK M.
System for Power Quality Estimation in LV Networks
Energetyka 2005, No. 12, p. 882 (IASE Bulletin p. 20), 1 fig.
There is described in the paper a realisation of the device for recording the curves of voltages and currents in LV networks; it is equipped with the sof- tware enabling to determine the electricity quality parameters and their conformance with standards. The system can serve too for recording optional curves (up to 16 measuring channels) in order to analyse their variation or to perform the spectral analysis of recorded data. The sampling frequency amounts up to 6400 Hz and can be set as an input parameter for the acquisition program. The mobile version of the system is described additionally.
New - Old Diagnostics Problems of Long Operated Power Equipment
Energetyka 2005, No. 12, p. 875 (Pro Novum Bulletin p. 13), 6 figs, 6 refs
Diagnostics of power equipment means logically integrated system of testing, result interpretation and formulating conclusion. An objective of the diagnostics is an assessment of the technical condition and forecast. Tests and measurements are its fragment only. The test programme should arise from the analysis of equipment operation history. Statistics of failures of equipment with near design, operating in similar conditions is the second important source of the knowledge at the elaboration of the test scope and the choice of the test methods. In the case of the power equipment operated longer than 150 000 h. diagnostic problems are rather good recognised and "new" problems very rare occur. An essence of professional diagnostics is not only to determine facts but first of all to interpret them and to draw the conclusions. Diagnosis gives advantages only, when it solves real problems, e.g. limiting or eliminating failure reasons, so creating conditions for improvement of security and availability, as well as extension of the equipment life time. Such approach to the diagnostics is obvious and known for a long time. However the practice shows that one tries rather frequently to discover truths known for long time or to create not existing "problems".
GRZESICZEK E., RAJCA S.
Examples of Failures of Rotor Discs Caused by Stress Corrosion
Energetyka 2005, No. 12, p. 881 (Pro Novum Bulletin p. 19), 1 tab., 20 figs, 3 refs
In that part of the turbine flow system where exists conditions for arising Wilson zone, i.e. when from saturated steam begins to condense the water (it causes that in beginning phase the great concentration of salt occurs), there exists the real danger of crack occurrence in places of stress accu- mulation, in area of key grooves on rotor disc hubs and at the edges of the blade grooves. There are presented in the paper examples of failures detected in last time and the manners of repair of failed elements and prevention ways against the failures are discussed.
State Assessment of Boiler Pipes which Wall Thickness Decreases as Consequence of Erosion and Corrosion
Energetyka 2005, No. 12, p. 886 (Pro Novum Bulletin p. 24), 1 tab., 1 fig., 3 refs
The EMA method described in the paper has an important advantage (measurement without touch) and it is very useful during exceptional tests and wall thickness measurements. Conventional ultrasonic method is more frequently used during accurate tests, when there is necessary to define more precisely flaw dimensions in material.
New Technologies in Steel Pipe Diagnostics
Energetyka 2005, No. 12, p. 888 (Pro Novum Bulletin p. 26), 9 figs, 6 refs
Magnetic tests of steel pipes have an essential importance for assuring operational security and reliability of the heat exchange equipment. Measurement gauges of the LRM-EMAT and LRM-RS types and measurement magnetic heads of the LRM-MH type enable to test the technical condition of steel pipes as from their inner side as from outside of the pipes as well.
MIKŁAS E., ŚLIWA A.
Failure of Feed Water Pump Caused by Corrosion of New Pipes in MP Heat Exchanger
Energetyka 2005, No. 12, p. 892 (Pro Novum Bulletin p. 30), 1 tab., 28 figs, 2 refs
During the 4 month operation of the power unit after it overhaul there occurred two cases of failure of the feed water pump. The balance disc and balance ring of the pump failed (they were seized). During the inspection of failed elements there were proved black sediments with ferromagnetic properties on their surfaces and these occurred within whole pump. As an effect of investigations there was ascertained that the arising place of the sediments and their emission was the new pipe cartridge for the MP heat exchanger. Reasons of the failure occurrence of the feed water pump and accompanying phenomena are presented.