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Wyniki wyszukiwania dla: FAULT DIAGNOSIS IN ELECTRONIC CIRCUITS
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Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
PublikacjaThe short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The...
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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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Low-frequency tripping characteristics of residual current devices
PublikacjaFast development of various types of converters makes their utilization in industry and in domestic installations very common. Due to converters, an earth fault current waveform in modern circuits can be distorted or its frequency can be different than 50/60 Hz. Frequency of earth fault (residual) current influences tripping of residual current devices which are widely used in low voltage systems. This paper presents the behaviour...
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Verification of safety in low-voltage power systems without nuisance tripping of residual current devices
PublikacjaLow-voltage power systems require initial and periodical verification to check the effectiveness of protection against electric shock. As a protection in case of fault, automatic disconnection of supply is most often used. To verify such a protection measure, the earth fault loop impedance or resistance is measured. This measurement is easy to perform in circuits without residual current devices. When residual current devices are...
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Broken rotor bar impact on sensorless control of induction machine
PublikacjaThe aim of the research is analysis of the sensorless control system of induction machine with broken rotor for diagnostic purposes. Increasing popularity of sensorless controlled variable speed drives requires research in area of reliability, range of stable operation, fault symptoms and application of diagnosis methods. T transformation (Cunha et al.,2003) used for conversion of instantaneous rotor currents electrical circuit...
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A method of earth fault loop impedance measurement without unwanted tripping of RCDs
PublikacjaIn low-voltage networks, earth fault loop impedance (EFLI) measurement is the basis for assessing the effectiveness of automatic disconnection of supply. Such a measurement is performed during initial and periodical verification, especially in a TN low-voltage network. Nowadays, due to widespread application of residual current devices (RCDs), such test is difficult in many circuits because RCDs operate during the test. In this...
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Behavior of residual current devices at earth fault currents with DC component
PublikacjaLow-voltage electrical installations are increasingly saturated with power electronic converters. Due to very high popularity of photovoltaic (PV) installations and the spread of electric vehicles (EV) as well as their charging installations, DC–AC and AC–DC converters are often found in power systems. The transformerless coupling of AC and DC systems via power electronic converters means that an electrical installation containing...
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SELECTION OF DIAGNOSTIC FUNCTIONS IN A WHEELED TRACTOR
PublikacjaIn a classical approach to damage diagnosis, the technical condition of an analyzed machine is identified based on the measured symptoms, such as performance, thermal state or vibration parameters. In wheeled tractor the fundamental importance has monitoring and diagnostics during exploitation concerning technical inspection and fault element localizations. The main functions of a diagnostic system are: monitoring tractor components...
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Analogue CMOS ASICs in Image Processing Systems
PublikacjaIn this paper a survey of analog application specific integrated circuits (ASICs) for low-level image processing, called vision chips, is presented. Due to the specific requirements, the vision chips are designed using different architectures best suited to their functions. The main types of the vision chip architectures and their properties are presented and characterized on selected examples of prototype integrated circuits (ICs)...
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Adaptive dynamic control allocation for dynamic positioning of marine vessel based on backstepping method and sequential quadratic programming
PublikacjaIt is generally assumed in dynamic positioning of over-actuated marine vessels that the control effectiveness matrix (input matrix) is known and constant, or, in case of fault information, it is estimated by the fault detection and diagnosis system. The purpose of the study is to develop the adaptive dynamic positioning control system for an over-actuated marine vessel in the presence of uncertainties and with emphasis on limited...
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Metoda diagnostyki łożysk na podstawie analizy przebiegów prądu i napięcia zasilającego silnik indukcyjny.
PublikacjaW niniejszej monografii przedstawiono oryginalne podejście i realizację diagnostyki łożysk silników indukcyjnych przy użyciu metody opartej na pomiarach i analizie iloczynu wartości chwilowych prądu i napięcia zasilającego maszyny. Uzyskane wyniki badań eksperymentalnych na obiektach rzeczywistych okazały się zbieżne z wynikami badań symulacyjnych i potwierdziły, że powstanie uszkodzeń łożysk w silniku skutkuje pojawieniem się...
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Detection of inter-turn faults in transformer winding using the capacitor discharge method
PublikacjaThe paper presents results of an analysis of inter-turn fault effects on the voltage and current waveforms of a capacitor discharge through transformer windings. The research was conducted in the frame of the Facility of Antiproton and Ion Research project which goal is to build a new international accelerator facility that utilizes superconducting magnets. For the sake of electrical quality assurance of the superconducting magnet...
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Risk Analysis by a Probabilistic Model of the Measurement Process
PublikacjaThe aim of the article is presentation of the testing methodology and results of examination the probabilistic model of the measurement process. The case study concerns the determination of the risk of an incorrect decision in the assessment of the compliance of products by measurement. Measurand is characterized by the generalized Rayleigh distribution. The model of the meas-urement process was tested in parallel mode by six risk...
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Machine Learning and Electronic Noses for Medical Diagnostics
PublikacjaThe need for noninvasive, easy-to-use, and inexpensive methods for point-of-care diagnostics of a variety of ailments motivates researchers to develop methods for analyzing complex biological samples, in particular human breath, that could aid in screening and early diagnosis. There are hopes that electronic noses, that is, devices based on arrays of semiselective or nonselective chemical sensors, can fill this niche. Electronic...
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Multilevel Converters
PublikacjaThe newest Special Section is intended to focus on recent research and trends in application of multilevel converters. Multilevel converters have been extensively developed over the last two decades and show several important advantages of power electronic circuits, such as: operation at high voltages, harmonics reduction, higher efficiency, modularity, smaller size and lower cost. Also, thanks to increasing interest in renewable...
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Dielectric Barrier Discharge Systems with HV Generators and Discharge Chambers for Surface Treatment and Decontamination of Organic Products
PublikacjaThe article presents applications of systems with power electronic converters, high voltage transformers, and discharge chambers used for nonthermal, dielectric barrier discharge plasma treatment of a plastic surface and decontamination of organic loose products. In these installations, the inductance of the high voltage transformers and the capacitances of the electrode sets form resonant circuits that are excited by inverters....
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Development of the sound field 3D intensity probe based on miniature microphones
PublikacjaThe engineered measuring probe uses three pairs of miniature microphones coupled. The signals from the microphones after an initial amplification are fed to differential circuits. Due to the required symmetry of the circuit it was necessary to select electronic components very carefully. Moreover, additional digital signal processing techniques were applied to avoid amplitude and phase mismatch. The view of the engineered probe...
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Testing sensitivity of A-type residual current devices to earth fault currents with harmonics
PublikacjaIn many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in...
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Dynamics of fault arc traveling along busbars in high voltage switchboards = Dynamika łuku zwarciowego przemieszczającego się wzdłuż szyn rozdziel-nic wysokiego napięcia
PublikacjaThe paper presents the results of magnetic induction and electrodynamic force calculations acting on arc column during short-circuit in medium voltage air-insulated bus-bars. The gap between the bars was 120 mm and the prospective short-circuit currents ranged from 4 kA to 8 kA. The paper also shows the measurement results of average velocity fault arc depending on currents arc diameter and arc current was established and described....
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Analysis of Induced Voltages and Power Losses in High Voltage Power Cables for Selected Methods of Cables Sheaths Bonding
PublikacjaPower is increasingly supplied to city centres with 110 kV cable lines. This is a convenient way to supply power, and practically the only one possible in areas of dense urban development. A high-voltage cable contains a coaxial metallic sheath, in which in normal operation and in fault conditions (during short-circuits) significant line-to-earth voltages can be induced, which threatens electric shock and/or damage to the cable’s...
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Magnetic Field Generated by Short Circuit Current in the 110 kV Power System
PublikacjaElectric fields within tissues induced by magnetic fields including transients or short-term peaks should not be time averaged and be regarded as instantaneous values as established in the ICNIRP (International Commission on Non - Ionizing Radiation Protection) guidelines. Measurements of power lines magnetic fields with regard to human beings exposure are carried out typically with maximum current load at current balance condition...
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Koncepcja, modelowanie i symulacja układu napędowego prototypu samochodu elektrycznego "ELV001"
PublikacjaAbstract: In this paper a conception, modelling and simulation tool for drive system of the prototype electric vehicle ''ELV001'' have been presented. The design and building of this vehicle have been carried out in frame of the project: ''Building a market of electric vehicle and charging infrastructure - fundamentals of energy safety''. The simulation tools are of great assistance to engineers and researchers to reduce product-development...
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RCDs Tripping in the Range from DC to AC 50 kHz for Slowly Rising Residual Current
PublikacjaThe wide use of power electronic converters means that in many low-voltage systems earth fault currents containing components from DC to AC of various frequencies have to be taken into account. Due to the tendency to increase the modulation frequency in converters, components of higher frequencies may be in the order of several tens of kilohertz. Therefore, it is very important to verify the behavior of devices for protection against...
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Time window based features extraction from temperature modulated gas sensors for prediction of ammonia concentration
PublikacjaElectronic gas recognition systems, in literature commonly referred as electronic noses, enable the recognition of a type and a concentration of various volatile compounds. Typical electronic gas-analyzing device consists of four main elements, namely, gas delivery subsystem, an array of gas sensors, data acquisition and power supply circuits and data analysis software. The commercially available metal-oxide TGS sensors are widely...
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Fault detection in the marine engine using a support vector data description method
PublikacjaFast detection and correct diagnosis of any engine condition changes are essential elements of safety andenvironmental protection. Many diagnostic algorithms significantly improve the detection of malfunctions.Studies on diagnostic methods are rarely reported and even less implemented in the marine engine industry.To fill this gap, this paper presents the Support Vector Data Description (SVDD) method as applied to thefault detection...
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Review of Methods for Diagnosing the Degradation Process in Power Units Cooperating with Renewable Energy Sources Using Artificial Intelligence
PublikacjaThis work is based on a literature review (191). It mainly refers to two diagnostic methods based on artificial intelligence. This review presents new possibilities for using genetic algorithms (GAs) for diagnostic purposes in power plants transitioning to cooperation with renewable energy sources (RESs). The genetic method is rarely used directly in the modeling of thermal-flow analysis. However, this assignment proves that the...
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Wybrane metody diagnostyki łożysk silników indukcyjnych oparte o pomiar prądu
PublikacjaW artykule zawarto przegląd wybranych metod diagnostyki łożysk silnika indukcyjnego, bazujących na pomiarach prądu zasilającego. Jedno z nowych rozwiązań przetwarzania sygnałów zostało zaadaptowane przez autorów do stosowanego przez nich systemu diagnostycznego. Wyniki wstępnych badań symulacyjnych zweryfikowanych badaniami na rzeczywistym obiekcie wskazują, że rozwiązanie to ułatwia diagnozowanie. Autorzy zamierzają prowadzić...
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Metoda diagnostyki cieplno-przepływowej turbin parowych wykorzystująca elementy algorytmów genetycznych
PublikacjaRozprawa doktorska poświęcona jest opisowi budowania metody diagnostyki cieplno-przepływowej z wykorzystaniem elementów algorytmów genetycznych. Do tworzenia założeń i algorytmów metody posłużono się przykładem funkcjonowania bloku elektrowni kondensacyjnej ze szczególnym uwzględnieniem układu łopatkowego turbiny parowej. Celem pracy jest zbudowanie metody diagnostyki cieplno-przepływowej. Zadaniem metody jest przeprowadzenie procesu...
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Distribution of relaxation times as a method of separation and identification of complex processes measured by impedance spectroscopy
PublikacjaImpedance spectroscopy is one of the most commonly performed measurements to characterize electronic and electrochemical systems. Impedance spectra have limited resolution and many different processes may overlap what could be the reason of obstructions in its proper later analysis. Up to date, there are three approaches to solve this problem: examining impedance spectra itself, fitting spectra with equivalent circuits, and calculating...
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A Development of a Capacitive Voltage Divider for High Voltage Measurement as Part of a Combined Current and Voltage Sensor
PublikacjaThis article deals with the development of capacitive voltage divider for high voltage measurements and presents a method of analysis and optimization of its parameters. This divider is a part of a combined voltage and current sensor for measurements in high voltage power networks. The sensor allows continuous monitoring of the network distribution status and performs a quick diagnosis and location of possible network failures....
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Diagnostic system of wheeled tractors detecting four defect's categories
PublikacjaIn a classical approach to damage diagnosis, the technical condition of an analyzed machine is identified based on the measured symptoms, such as performance, thermal state or vibration parameters. In wheeled tractor the fundamental importance has monitoring and diagnostics during exploitation concerning technical inspection and fault element localizations. The main functions of a diagnostic system are: monitoring tractor components...
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Study of oxygen electrode reactions on symmetrical porous SrTi0.30Fe0.70O3-δ electrodes on Ce0.8Gd0.2O1.9 electrolyte at 800 °C–500 °C
PublikacjaIron doped strontium titanates (SrTi1-xFexO3-δ) are an interesting mixed ionic-electronic conductor model used to study basic oxygen reduction/oxidation reactions. In this work, we performed an impedance spectroscopy study on symmetrical porous SrTi0.30Fe0.70O3-δ (STF70) electrodes on a ceriabased electrolyte. The sample was measured in varying oxygen concentration: from 0.3% to 100% in 800 °C - 500 °C temperature range. Low polarisation...
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Application of infrared thermoography to non-contact testing of varistors
PublikacjaTesting of varistors using thermography was carried out in order to assess their protective properties against possible overvoltage phenomena in the form of high-level voltage surges. An advantage of the thermography technique is non-contact temperature measurement. It was proposed to assess the properties of varistors workingin electronic devices as protective elements, on the basis of estimating temperature increments on varist...
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COMPARISON OF SYSTEM ON CHIP TECHNOLOGIES FOR SPACE APPLICATIONS
PublikacjaThe paper presents a review of technologies available for the implementation of digital and mixed signal systems, particularly the system on a chip (SoC) for space applications. The phenomena encountered in the space environment are briefly presented, together with the known solutions, regarding the design of complex electronic systems. The most important norms regarding single die integrated circuits designed for space are also...
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Diagnostyka uszkodzeń analogowych układów elektronicznych z zastosowaniem specjalizowanej sieci neuronowej
PublikacjaNa tle trendów rozwojowych diagnostyki analogowych układów elektronicznych AEC (Analog Electronic Circuits), przedstawiono nową metodę diagnostyki uszkodzeń parametrycznych układów analogowych, ze specjalizowanym klasyfikatorem neuronowym, o zwiększonej odporności na tolerancje elementów układu i niepewności pomiaru. Zastosowano specjalizowaną sieć neuronową z dwucentrowymi funkcjami bazowymi TCRBF (Two-center Radial Basis Function),...
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STANY NIEUSTALONE TOWARZYSZĄCE POMIAROWI IMPEDANCJI PĘTLI ZWARCIA W OBWODACH WYJŚCIOWYCH ZASILACZY BEZPRZERWOWYCH UPS
PublikacjaW pracy przedstawiono metodykę i wyniki pomiarów stanów nieustalonych w zasilaczu bezprzerwowym (UPS) typu on - line. Do rejestracji zdarzeń po stronie zasilania i na wyjściu UPS wykorzystano dwa przyrządy do pomiaru jakości energii elektrycznej zsynchronizowane czasowo. Rejestratory kompresują uzyskane dane pomiarowe, co może wprowadzać dodatkowe błędy pomiaru wielkości mierzonych – napięć i prądów. Dodatkowe rejestracje oscyloskopem...
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The Multiplatform Environment for Simulation and Features Estimation of Mixed-Signal Devices
PublikacjaThe use of simulation laboratories is gaining popularity in thedomains of engineering programs. However, the experience in teaching showsthat the simulation itself is not very effective in didactic processes. Teachingprocesses in thefield of specialist subjects, designed for students of technicaluniversities, should be based on direct operations performed by the student onreal devices. At the same time, at the later stages of didactic...
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A System for Heart Sounds Classification
PublikacjaThe future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods. As for the cardiac diseases – one of the major causes of death around the globe – a concept of an electronic stethoscope equipped with an automatic heart tone identification system appears to be the best solution. Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue. However,...
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Multimodal human-computer interfaces based on advanced video and audio analysis
PublikacjaMultimodal interfaces development history is reviewed briefly in the introduction. Examples of applications of multimodal interfaces to education software and for the disabled people are presented, including interactive electronic whiteboard based on video image analysis, application for controlling computers with mouth gestures and the audio interface for speech stretching for hearing impaired and stuttering people. The Smart...
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On Decision-Making Strategies for Improved-Reliability Size Reduction of Microwave Passives: Intermittent Correction of Equality Constraints and Adaptive Handling of Inequality Constraints
PublikacjaDesign optimization of passive microwave components is an intricate process, especially if the primary objective is a reduction of the physical size of the structure. The latter has become an important design consideration for a growing number of modern applications (mobile communications, wearable/implantable devices, internet of things), where miniaturization is imperative due to a limited space allocated for the electronic circuitry....
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Li nucleation on the graphite anode under potential control in Li-ion batteries
PublikacjaApplication of Li-ion batteries in electric vehicles requires improved safety, increased lifetime and high charging rates. One of the most commonly used intercalation anode material for Li-ion batteries, graphite, is vulnerable to Li nucleation, a side reaction which competes with the intercalation process and leads to loss of reversible capacity of the battery, ageing and short-circuits. In this study, we deploy a combined grand...
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Youth Civic Participation in the South Baltic Region. Example of Lithuania, Poland and Sweden
PublikacjaThe aim of this study was to show youth civic participation as a social inclusion element in the Southern Baltic region in need of reinforcement, based on the examples of selected municipalities from Lithuania, Poland and Sweden. The authors focused on the diagnosis of key elements of youth civic engagement at local and cross-border level, taking into account the context of national youth policies and the European Union policy....
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New Applications of Multimodal Human-Computer Interfaces
PublikacjaMultimodal computer interfaces and examples of their applications to education software and for the disabled people are presented. The proposed interfaces include the interactive electronic whiteboard based on video image analysis, application for controlling computers with gestures and the audio interface for speech stretching for hearing impaired and stuttering people. Application of the eye-gaze tracking system to awareness...