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Wyniki wyszukiwania dla: WELDABILITY
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Evaluation of conductive-to-resistive layers interaction in thick-film resistors
PublikacjaSpektroskopia szumowa w zakresie małych częstotliwości jest używana do badania oddziaływania warstwy rezystywnej i przewodzącej w wytwarzanych rezystorach grubowarstwowych. Wprowadzono dwa parametry szumowe do określania stopnia tego oddziaływania. Opisano wyniki przeprowadzonych badań oddziaływania warstw z dwutlenku rutenu, rutenku bizmutu z kontaktami ze złota, platyna-złoto, pallad-srebro, od różnych producentów.
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Self-testing of fully differential multistage circuits using common-mode excitation
PublikacjaPrzedmiotem artykułu jest, zorientowane na uszkodzenia, testowanie wielostopniowych układów w pełni różnicowych. Zaproponowano metodę testowania z zastosowaniem pobudzenia układu testowanego sygnałem wspólnym. Rozważane są dwa warianty metody. Pierwszy wariant wykorzystuje do pobudzenia wejście każdego różnicowego stopnia. Drugi wariant wykorzystuje dodatkowe wejście wzmacniacza operacyjnego i testuje wielostopniowy układ bez jego...
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FFT analysis of temperature modulated semiconductor gas sensor response for the prediction of ammonia concentration under humidity interference
PublikacjaThe increasing environmental contamination forces the need to design reliable devices for detecting of the volatile compounds present in the air. For this purpose semiconductor gas sensors, which have been widely used for years, are often utilized. Although they have many advantages such as low price and quite long life time, they still lack of long term stability and selectivity. Namely, environmental conditions have significant...
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Quality assessment of ZnO-based varistors by 1/f noise
PublikacjaNoise has been used as a diagnostic tool of surge arrester varistor structures comprising of ZnO grains of various type and size. The physical and electrical properties of the measured samples have been described. In the experimental study, the applied measurement system and the results of noise measurements for the selected structures of varistors designed for the continuous working voltage 280 V, 440 V and 660 V have been presented....
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The semi-Markov model of the process of appearance of sea-going ship propupsion system ability and inability states in application to determining the reliablity of these systems
PublikacjaThe article presents possible application of the theory of semi-Markov processes in creating the eight-state model of the process of appearance of the propulsion systems ability and inability states on sea-going vessels performing transportation tasks in a relatively long operating time t (t → ∞). The model has been proved to be able to be successfully used for determining the reliability of the abovementioned systems. The probability...
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Single and Series of Multi-valued Decision Diagrams in Representation of Structure Function
PublikacjaStructure function, which defines dependency of performance of the system on performance of its components, is a key part of system description in reliability analysis. In this paper, we compare two approaches for representation of the structure function. The first one is based on use of a single Multi-valued Decision Diagram (MDD) and the second on use of a series of MDDs. The obtained results indicate that the series of MDDs...
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Underwater wet welding of S1300 ultra-high strength steel
PublikacjaMarine Structures Volume 81, January 2022, 103120 Underwater wet welding of S1300 ultra-high strength steel Author links open overlay panelJacekTomkówGrzegorzRogalski https://doi.org/10.1016/j.marstruc.2021.103120 Get rights and content Under a Creative Commons licenseopen access Highlights • Technological method of S1300 steel underwater weldability improving was proposed. • Number of cracks and hardness of welded joints was...
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Transport of dangerous goods by rail, and threats to the subsoil of the railway surface in the event of a disaster
PublikacjaIn Poland, in 2020, the mass of dangerous goods (loads) transported by rail was 26 151.06 thousand tone. This translated into the performance of 8 899 691.89 thousand tone - km of transport performance. In 2020, these figures accounted for 11.72% of the weight of goods transported by rail. The situation is similar in other countries around the world. With such a large volume of transport of dangerous...
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DETERMINATION OF DIFFUSIBLE HYDROGEN CONTENT IN DEPOSITED METAL OF RUTILE ELECTRODES BY GLYCERIN METHOD
PublikacjaThe presence of diffusible hydrogen in welded joints is one of the causes of formation the welding imperfections. Improvement of weldability can be achieved by reducing the hydrogen amount in welded joints. This requires, among others, the finding of sources of hydrogen. For high hydrogen processes the commonly used method of determining the diffusible hydrogen amount is the glycerin method. This paper concerns issues related to...
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Availability of UAV Fleet Evaluation Based on Multi-State System
PublikacjaUnmanned Aerial Vehicle (UAV) applications are extended extremely. Some applications need to use several UAVs for a general mission which can be considered a UAV fleet. One of the important characteristics for the evaluation of a UAV or UAV fleet is reliability. There are studies in which methods for analysis of their reliability are considered. Reliability analysis of UAV fleets is less frequently studied, although a single UAV...
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Multi-objective optimization of water quality, pumps operation, and storage sizing of water distribution systems
PublikacjaA multi-objective methodology utilizing the Strength Pareto Evolutionary Algorithm (SPEA2) linked to EPANET for trading-off pumping costs, water quality, and tanks sizing of water distribution systems is developed and demonstrated. The model integrates variable speed pumps for modeling the pumps operation, two water quality objectives (one based on chlorine disinfectant concentrations and one on water age), and tanks sizing cost...
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Redundancja jako sposób zwiększenia niezawodności siłowni okrętowych
PublikacjaJednym z istotnych sposobów zapewnienia wysokiego poziomu niezawodności siłowni okrętowych jest zaprojektowanie redundancji jego elementów strukturalnych, np.: nadmiarowości strukturalnej systemów generowania energii, układów napędowych itp. W niniejszym artykule omówiono zagadnienia związane z nadmiarem, jako sposobem zwiększenia niezawodności systemów generowania energii i napędu statku. W szczególności zaś zostały zaprezentowane...
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Distributed VoIP telecommunication system
PublikacjaIn the paper a distributed VoIP telecommunication system architecture with load balancing is described. Important features of this architecture are the high level of system reliability and the possibility of using lowcost hardware solutions.
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Effect of shielded electrode wet welding conditions on diffusible hydrogen content in deposited metal
PublikacjaWet welding is the most popular method of joining in water enviroment. During underwater welding, the weldability of steel is limited by the higher cooling rates and hydrogen content in weld metal. Article presents results of preliminary tests on the effects of wet welding conditions on diffusible hydrogen amount. Seven parameters were optimized using a Plackett-Burman plan to get the most relevant variables. These parameters were:...
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The role of robotisation in improving bakery product quality
PublikacjaThe article aims to present the role of robotisation in increasing bakery product quality, as it is closely linked to machine reliability, as well as hygienic and sanitary conditions. All machines employed in the production process ought to be maintained at full production potential and reliability, which also has a fundamental influence on the final product’s quality. While participating in the 2014-2020 Smart Growth Operational...
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Analysis of measurement uncertainty for contact-less method used to measure the position of catenary contact wire, performed with the use of Monte Carlo method
PublikacjaCurrently the majority of main railway lines in Europe are electrified, and electric trains have the biggest share in the entire amount of rail transport. Reliability of electrified railways is closely related to the issue of supplying traction vehicles with energy. The problems connected with diagnostics of energy consumption node, namely the contact line and the current collector, are therefore of fundamental importance for maintaining...
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Future research directions in design of reliable communication systems
PublikacjaIn this position paper on reliable networks, we discuss new trends in the design of reliable communication systems. We focus on a wide range of research directions including protection against software failures as well as failures of communication systems equipment. In particular, we outline future research trends in software failure mitigation, reliability of wireless communications, robust optimization and network design, multilevel...
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Assessment of crack resistance of ship steels according to SEP 1390 standard
PublikacjaThe aim of the study was to evaluate the weldability of E36 nd NVE-36 steels by bending test according to SEP 1390. In the case of the specimen from E36 steel 9 external cracks were found, 5 of which were stopped in the fusion line and 4 in heat affected zone. In the case of the specimen from NVE-36 steel 8 external cracks were found, 4 of which were stopped in the fusion line and 4 in heat affected zone. Results of bending test...
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Exploring the trends in flux-cored arc welding: scientometric analysis approach
PublikacjaFlux-cored arc welding (FCAW) is a universal group of welding methods in terms of the scope of application and automation possibilities, the share of which in various industries in many countries is still increasing. The paper presents the results of bibliographic analyses (scientometric analysis with the use of VOSviewer, Bibliometrix and CitNetExplorer tools) of a data set of 993 publications indexed in the Web of Science database...
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Application of commercial microwave links (CMLs) attenuation for quantitative estimation of precipitation
PublikacjaPrecipitation estimation models are typically sourced by rain gauges, weather radars and satellite observations. A relatively new technique of precipitation estimation relies on the network of Commercial Microwave Links (CMLs) employed for cellular communication networks: the rain-inducted attenuation in the links enables the precipitation estimation. In the paper, it is analysed to what extent the precipitation derived from CML...
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Polish Adaptation of the Pregnancy-Related Anxiety Questionnaire—Revised 2 for All Pregnant Women
PublikacjaPregnancy-related anxiety (PrA) is a specific type of anxiety characteristic of the perinatal period. PrA can affect pregnancy and birth. However, no validated tool exists to measure PrA in Polish obstetric practice. The aim of this study was to translate the Pregnancy-Related Anxiety Questionnaire—Revised 2 (PRAQ-R2) into Polish and to evaluate its reliability and factorial and construct validity. This study was conducted in Poland...
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Experimental research on marine oil-lubricated stern tube bearing
PublikacjaBearings of propeller shafts are very crucial elements of the propulsion system of each of the ships. The safety of shipping depends on their durability and reliability. The new legal restrictions mean that today we are looking for environmentally friendly solutions. That is why water-lubricated bearings are becoming more and more popular. So, will oil-lubricated shaft bearings belong to the past? The bearing with a white metal...
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Health monitoring services based on off-the-shelf mobile devices
PublikacjaDevelopment of health monitoring systems usually involves usage of dedicated devices with provided guarantees in terms of their reliability. Those devices raise the cost of the whole system, because of which such platforms are limited only to specific areas and constrained number of users. Usage of off-the- shelf devices could lower the cost and bring those systems to the masses. The paper covers possible uses of common off-the-shelf...
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Genetic Programming for Workload Balancing in the Comcute Grid System
PublikacjaA genetic programming paradigm is implemented for reliability optimization in the Comcute grid system design. Chromosomes are generated as the program functions and then genetic operators are applied for finding Pareto-suboptimal task assignment and scheduling. Results are compared with outcomes obtained by an adaptive evolutionary algorithm.
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COLREGS compliance in Evolutionary Sets of Cooperating Ship Trajectories
PublikacjaIn general, Evolutionary Sets of Cooperating Ship Trajectories combine some of the assumptions of game theory with evolutionary programming and aim to find optimal set of cooperating trajectoriesof all ships involved in an encounter situation. In a two-ship encounter situation the method enables the operator of an on-board collision-avoidance system to predict the most probable behaviour of atarget and to plan the own manoeuvres...
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MODEL OF MULTILEVEL STOCHASTIC ANALYSIS OF ROAD SAFETY ON REGIONAL LEVEL
PublikacjaIn this paper multilevel approach to the issue of road safety level on the road network of European regions, classified as NUTS 2 in statistical databases of the European Union, has been presented. Following the pattern of many publications on road safety it has been assumed that the risk calculated as the number of death casualties in road accidents per 100,000 inhabitants of a given region has Poisson distribution. Therefore,...
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Treatment Wetlands in Rural Areas of Poland for Baltic Sea Protection
PublikacjaWater and wastewater management, especially in rural areas, greatly affects loads of nutrients discharged to the Baltic Sea. In Poland, this management is unbalanced because of the dispersed development and in many locations construction of sewerage system is uneconomic or even impossible. For this reason, a significant part of sewage from single-family houses in rural areas must be discharged into domestic sewage systems. The...
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COLD CRACKING OF S460N STEEL WELDED IN WATER ENVIRONMENT
PublikacjaThis paper shows results of weldability testing of fine-grained high -strength low- alloy S460N steel welded in water environment by covered electrodes. The tests were carried out by using the CTS test specimens with fillet welds. Four specimens were welded under water and one specimen in air. Welded joints were subjected to non-destructive visual and penetration tests. The accepted joints were then subjected to macroscopic and...
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Size and mass minimization of capacitor bank in a power converter DC line of DC drive with closed loop control system with PWM and current limitation
PublikacjaPaper deals with evaluation equations for power filter of AC-DC power converter which allows to provide size and mass minimization of capacitor bank in DC drive closed loop systems with PWM and current limitation. Reliability of provided equations is proved by simulation in MATLAB/Simulink
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Fault detection and diagnostics of complex dynamic systems using Gaussian Process Models - nuclear power plant case study
PublikacjaThe article examines the use of Gaussian Process Models to simulate the dynamic processes of a Pressurized Water nuclear Reactor for fault detection and diagnostics. The paper illustrates the potential of Gaussian Process Models as a tool for monitoring and predicting various fault conditions in Pressurized Water nuclear Reactor power plants, including reactor coolant flow and temperature variations, deviations from nominal working...
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Cold Cracking Of Underwater Wet Welded S355G10+N High Strength Steel
PublikacjaWater as the welding environment determines some essential problems influencing steel weldability. Underwater welding of high strength steel joints causes increase susceptibility to cold cracking, which is an effect of much faster heat transfer from the weld area and presence of diffusible hydrogen causing increased metal fragility. The paper evaluates the susceptibility to cold cracking of the high strength S355G10+N steel used,...
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Application of principal component and hierarchical cluster analysis in classifying defects of trolleybuses
PublikacjaThe failure rate of vehicles is a relevant task, which is strictly connected with the reliability of transportation systems. Methods of data analysis allow us to find similarity and differences between failure rates of several parts of trolleybuses. This paper deals with the statistic of failure of trolleybuses from the municipal transport company of Gdynia (Poland).
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Hybrid constructed wetlands for the National Parks in Poland - a case study, requirements, dimensioning, preliminary results
PublikacjaWater and wastewater management, especially in rural areas, greatly affects loads of nutrients discharged to the Baltic Sea. In Poland, this management is unbalanced because of the dispersed development and in many locations con struction of sewerage system is uneconomic or even impossible. For this reason, a significant part of sewage from single-family houses in rural areas must be discharged into domestic sewage systems. The...
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Implementation of integrated control In drinking water distribution systems - IT system proposal
PublikacjaImplementation of integrated control algorithms requires suitable hardware and software platforms. Proposed solution must allow realizing control and monitoring tasks, while ensuring high reliability and security of processed data. Additionally, the software and hardware solutions must be immune to outside influence. This paper presents an approach to implementation of control systems in drinking water distribution system. Presented...
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Horizontal velocity field derived from EPN and ASG-EUPOS satellite data on the example of south-western part of Poland
PublikacjaPresently the determination of the velocity field in the global reference frame is possible by using different space techniques and dense terrestrial networks from global to local and regional scales. However, the reliability of such determinations is strongly limited by the restricted number of unmodeled effects. Some of them are periodic (atmospheric or hydrological effects), some instantaneous (natural or man-made seismicity)...
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Temper bead welding of S460N steel in wet welding conditions
PublikacjaWet welding is the most common method of welding in water environment. It is most often used for repairing of underwater parts of offshore structures. However, the water as a welding environment causes an increase of susceptibility of steels to cold cracking. For underwater constructions high strength low alloy (HSLA) steel are widely used. In wet welding condition a HSLA steel is characterized by high susceptibility to cold cracking....
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An experimental study of high-hydrogen welding processes
PublikacjaThis paper presents investigation results of determination of the diffusible hydrogen content in deposited metal obtained by means of two most often used methods-the glycerin method and the mercury method. Relation has been defined between results of those methods in the area characteristic of low-hydrogen as well as high-hydrogen welding processes. Relations available in the literature do not include the diffusible hydrogen content...
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Five-phase Induction Motor Drive Operation During Stator Phase Fault
PublikacjaThe article presents the most important advantages of multi-phase electric drives. The construction of a five-phase squirrel cage induction motor together with possible stator winding distribution cases is presented, which affect the properties of such motor. Increased reliability of five-phase drives was indicated. The drive operation properties were confirmed by experimental results.
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Machine Learning Algorithm-Based Tool and Digital Framework for Substituting Daylight Simulations In Early- Stage Architectural Design Evaluation
PublikacjaThe aim of this paper is to examine the new method of obtaining the simulation-based results using backpropagation of errors artificial neural networks. The primary motivation to conduct the research was to determine an alternative, more efficient and less timeconsuming method which would serve to achieve the results of daylight simulations. Three daylight metrics: Daylight Factor, Daylight Autonomy and Daylight Glare Probability have...
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Discovery of Stylistic Patterns in Business Process Textual Descriptions: IT Ticket Case
PublikacjaGrowing IT complexity and related problems, which are reflected in IT tickets,create a need for new qualitative approaches. The goal isto automate the extraction of main topics described in tickets in order to provide high quality support for the IT process workers and enablea smooth service delivery to the end user. Present paper proposes a method of knowledge extraction in a form of stylistic patterns in business...
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Nonlocalized thermal behavior of rotating micromachined beams under dynamic and thermodynamic loads
PublikacjaRotating micromachined beams are one of the most practical devices with several applications from power generation to aerospace industries. Moreover, recent advances in micromachining technology have led to huge interests in fabricating miniature turbines, gyroscopes and microsensors thanks to their high quality/reliability performances. To this end, this article is organized to examine the axial dynamic reaction of a rotating...
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Selected Problems of Cogeneration Energy Systems Designing, Fueled with Landfill Biogas
PublikacjaThe article discusses the impact of the quality of biogas fuel for operation of generating sets with internal combustion engines. There are presented selected investigation results of landfill biogas fueled gensets operation. The article includes also discussion of the possibility of increasing the efficiency of biogas fuelled cogeneration systems. It also presents guidelines for the optimal design of landfill biogas fueled engines,...
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Immunity of residual current devices to the impulse leakage current in circuits with variable speed drives
PublikacjaThis paper concerns reliability of supply in variable speed drive circuits with residual current devices. During normal operation of these circuits high value of leakage current causes unwanted tripping of residual current devices. Immunity of residual current devices to the impulse leakage current should be evaluated. The system for testing of residual current devices and results of the test are presented
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Zastosowanie techniki ściegu odpuszczającego do spawania mokrego
PublikacjaW artykule przedstawiono zastosowanie techniki ściegu odpuszczającego do poprawy właściwości złączy ze stali konstrukcyjnych wykonywanych w warunkach mokrego spawania pod wodą. Scharakteryzowano spawanie mokre elektrodami otulonymi zmiany struktury i właściwości złączy spawanych przez nakładanie ściegów odpuszczających. Przedstawiono metodykę oraz wyniki badań metalograficznych i twardości próbek ze stali konstrukcyjnej o podwyższonej...
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Testing the Weibull distribution in road traffic losses analysis
PublikacjaThe paper presents an attempt of applying the Weibull distribution for the purpose of analysing road traffic losses (fatalities). The question it asks is whether reliability engineering methods can be applied for the analyses. If this is the case, what should be the interpretation of the numbers and terms? It was assumed that the losses generated by a malfunctioning road transport system are fatalities. Risk exposure to these losses...
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SIMPLIFIED MODELING OF STRESS AND DEFLECTION LIMIT STATES OF UNDERGROUND TANKS
PublikacjaFuel tanks are designed with regard to standard actions and operating conditions. The work analyses the impact of corrosion and other means to variation of stresses and deformation of a horizontal underground tank shell. The computations are preliminary. Due to the long computational time of the entire tank the analysis is restricted to its part only. The full analysis is bound to assess structural reliability, further allowing...
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Analiza Niezawodności Człowieka w Ramach Funkcji związanych z Bezpieczeństwem w Przykładowej Instalacji
PublikacjaW analizie bezpieczeństwa funkcjonalnego systemów sterowania i zabezpieczeń należy określić wymagany poziom nienaruszalności bezpieczeństwa SIL w procesie analizy ryzyka, a następnie zweryfikować ten poziom stosując odpowiednie metody modelowania probabilistycznego. Działania człowieka mogą mieć istotny wpływ na realizację funkcji bezpieczeństwa. Wpływ ten ocenia się na podstawie wyników analizy niezawodności człowieka HRA. W niniejszym...
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Voltage Control of a Stand-Alone Multiphase Doubly Fed Induction Generator
PublikacjaThis article presents a multiphase doubly fed induction generator (MDFIG) with a dedicated and unique control algorithm in a stand-alone wind energy conversion system. The algorithm has been developed and elaborated in the case of different emergency modes. Compared with the traditional double-fed induction generator, the MDFIG has increased reliability, reduced current level per phase, and low rotor harmonic currents. The control...
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Quality Modeling in Grid and Volunteer-Computing Systems
PublikacjaA model of computational quality in large-scale computing systems was presented in the previous chapter of this book. This model describes three quality attributes: performance, reliability and energy efficiency. We assumed that all processes in the system are incessantly ready to perform calculations and that communication between the processes occurs immediately. These assumptions are not true for grid and volunteer computing...
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Frequency Diagnostics of Transformer Insulating Parameters
PublikacjaIn the article is presented experimental analysis and diagnostics of insulating system oil-paper for power transformers, mainly by progressive frequency method – dielectric spectroscopy. In the 1-st part of the article is described base theory about measurement and diagnostics insulating part (oil and paper) of power transformers. In the 2-nd part of article is described measuring method of insulating frequency diagnostics - frequency...