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Search results for: NOISE GENERATORS
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Distance measurement errors in silent FM-CW sonar with matched filtering
PublicationThe secretiveness of sonar operation can be achieved by using continuous frequency-modulated sounding signalswith reduced power and significantly prolonged repeat time. The application of matched filtration in the sonarreceiver provides optimal conditions for detection against the background of white noise and reverberation, and avery good resolution of distance measurements of motionless targets. The article shows that target...
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Self-Optimizing Adaptive Vibration Controller
PublicationThis paper presents a new approach to rejection of sinusoidal disturbances acting at the output of a discrete-time linear stable plant with unknown dynamics. It is assumed that the frequency of the sinusoidal disturbance is known, and that the output signal is contaminated with wideband measurement noise. The proposed controller, called SONIC (self-optimizing narrowband interference canceller), combines the coefficient fixing technique,...
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Elimination of impulsive disturbances from stereo audio recordings
PublicationThis paper presents a new approach to elimination of impulsive disturbances from stereo audio recordings. The proposed solution is based on vector autoregressive modeling of audio signals. On-line tracking of signal model parameters is performed using the stability-preserving Whittle-Wiggins-Robinson algorithm with exponential data weighting. Detection of noise pulses and model-based interpolation of the irrevocably distorted samples...
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Scientific research in the Department of Machine Design and Automotive Engineering
PublicationShort descriptions of various research subjects taken up at the Department of Machine Design and Automotive Engineering are included in the paper. The subjects cover a wide range of bearing systems and tribology research and the research on tires and road surfaces. A third field of activity is biomedical engineering – with the attempts to improve methods of modelling biological materials in FEM calculations. The Department has...
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Analysis of soundscape recordings in close proximity to the road in changeable wather conditions
PublicationThe acoustic vehicle sensing is the least invasive type of traffic detection. Also, acoustic-based vehicle detection technology is insensitive to precipitation and can operate in low light level. Therefore, this kind of method may be used for automatic detection of the vehicle passage events. It can also be employed for measurements of a vehicle speed and the vehicle assignment to the particular category. In this paper the results...
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Vapor correction of FTIR spectra – A simple automatic least squares approach
PublicationFTIR spectroscopy is one of the best techniques to study intermolecular interactions. However, such an application requires high quality spectra with as little noise as possible, which are often difficult to obtain. One of the main sources of unwanted interference is water vapor. Here a robust method is proposed for automatic, fast and reliable vapor correction of FTIR spectra. The presented least squares approach of vapor subtraction...
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Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublicationThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...
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Azimuth estimator for a rotating array radar with wide beam
PublicationThe problem of estimating azimuth in rotating array radar with a beam, wide in the azimuth plane, is considered. Under such setup the echo signal usually has a very low signal to noise ratio, but the number of observations is large, because of long dwell times. The proposed solution is based on the maximum likelihood approach, but it employs simplifications which facilitate its implementation in real time systems. Results, obtained...
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Towards Audio Signal Equalization Based on Spectral Characteristics of a Listening Room and Music Content Reproduced
PublicationThis study presents investigations of the influence of the room acoustics on the frequency characteristic of the audio signal playback. First, the concept of a novel spectral equalization method of the room acoustic conditions is introduced. On the basis of the room spectral response, a system for room acoustics compensation based on an equalizer designed is proposed. The system settings depend on music genre recognized automatically....
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Open-transistor fault diagnostics in voltage-source inverters by analyzing the load current
PublicationA novel method is presented for the detection andisolation of open-transistor faults in voltage-source invertersfeeding low-power AC motors. The method is based onmonitoring two diagnostic signals, one indicating sustained nearzerovalues of output current and thus permitting fault detection,the other permitting the isolation of the particular transistorwhich went faulty. The latter signal is the ratio of the averagephase current...
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The study of acoustic climate of the Southern Baltic
PublicationThis paper presents the statistical characteristics of seawater properties, which are necessary for predicting the propagation of acoustic waves in selected areas of the Baltic Sea. The statistics were elaborated based on long-term measurements of vertical distributions of sound speed, temperature, and salinity, and the nonlinearity parameter B/A. Nonlinear properties of the environment are considered, in connection...
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Fluctuation-Enhanced Sensing (FES): A Promising Sensing Technique
PublicationFluctuation-enhanced sensing (FES) is a very powerful odor and gas sensing technique and as such it can play a fundamental role in the control of environments and, therefore, in the protection of health. For this reason, we conduct a comprehensive survey on the state-of-the-art of the FES technique, highlighting potentials and limits. Particular attention is paid to the dedicated instrumentation necessary for the application of...
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Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublicationThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
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Analiza jakości transmisji treści audio-wideo w symulowanym łączu telekomunikacyjnym z wykorzystaniem techniki OFDM
PublicationWdrożenie niezawodnego systemu komunikacji audio-wideo przynosi wiele korzyści. Z uwagi na fakt, że ilość dostępnego pasma stale się kurczy, badacze koncentrują się na nowatorskich metodach transmisji. Obecnie technika OFDM (Orthogonal Frequency Division Multiplexing) jest szeroko stosowana zarówno w mediach przewodowych, jak i bezprzewodowych. W pracy przedstawiono badania jakości QoS (Quality of Service) symulowanego łącza transmisji...
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AN INTELLIGENT SYSTEM TO SUPPORT THE DESIGN PROCESS OF HYBRID PHOTOVOLTAIC INSTALLATIONS
PublicationThe paper presents the final version of intelligent system to support the design process of hybrid photovoltaic systems supported by fuel cells and / or thermoelectric generators developed and constructed at the Institute of Electron Technology, as well as to conduct experiments and research. A block diagram of the system and the selection of its components is described and discussed. The paper considers the availability of the...
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Surface Dielectric Barrier Discharge Plasma Actuators
PublicationThis paper presents a part of the works conducted in the Plasmaero European project (task 1.1) on surface dielectric barrier discharge actuators applied to airflow control. The study is divided into several parts. In the first part, the goal is to enhance the electric wind produced by a typical single DBD actuator by optimization of the active electrode shape. For instance, the use of a thin wire instead of a plate air-exposed...
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Wideband Model Order Reduction for Macromodels in Finite Element Method
PublicationAbstract: This paper presents a novel algorithm for accelerating 3D Finite Element Method simulations by introducing macromodels created in local model order reduction in the selected subdomains of the computational domain. It generates the projection basis for a compact system of equations associated with a separate subdomain. Due to non-linear frequency dependency in the Right Hand Side (RHS), the standard reduction methods do...
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A fast time-frequency multi-window analysis using a tuning directional kernel
PublicationIn this paper, a novel approach for time-frequency analysis and detection, based on the chirplet transform and dedicated to non-stationary as well as multi-component signals, is presented. Its main purpose is the estimation of spectral energy, instantaneous frequency (IF), spectral delay (SD), and chirp rate (CR) with a high time-frequency resolution (separation ability) achieved by adaptive fitting of the transform kernel. We...
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Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines. Part I: Steady-state processes
PublicationThe article presents a possible method of detecting failures in the flow section and supply system of a naval gas turbine engine based on the exhaust gas temperature measured behind the gas generator. This temperature is a basic diagnostic parameter use for evaluating the technical state of the turbine engine in operation, and is monitored during engine start-ups, accelerations and decelerations of rotor units, and steady-load...
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Power augmentation of PGE Gorzow's gas turbine by steam injection - thermodynamic overview
PublicationThe impact of steam injection upon a gas turbine and a combined power plant performance has been investigated. This article describes and summarizes possibilities of modification for current gas turbine in PGE Gorzow power plant into the Cheng cycle. Our modification deals with a thermal cycle, in which steam produced in a heat recovery steam generator is injected into the gas turbine's combustion chamber. It has been proved that...
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Efficient FPGA Implementation of an RFIR Filter Using the APC–OMS Technique with WTM for High-Throughput Signal Processing
PublicationNowadays, Finite Impulse Response (FIR) filters are used to change the attributes of a signal in the time or frequency domain. Among FIR filters, a reconfigurable filter has the advantage of changing the coefficient in real-time, while performing the operation. In this paper, the Anti-Symmetric Product Coding (APC) and Odd Multiple Storage (OMS) modules are utilized to implement the reconfigurable FIR filter (RFIR–APC–OMS). Herein,...
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Quantum security and theory of decoherence
PublicationWe sketch a relation between two crucial, yet independent, fields in quantum information research, viz. quantum decoherence and quantum cryptography. We investigate here how the standard cryptographic assumption of shielded laboratory, stating that data generated by a secure quantum device remain private unless explicitly published, is disturbed by the einselection mechanism of quantum Darwinism explaining the measurement process...
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Measurements of passive components using of an IEEE 1149.4 mixed-signal test bus
PublicationW pracy przedstawiono wyniki badań nad wykorzystaniem magistrali testującej mieszanej sygnałowo IEEE 1149.4 do pomiarów elementów pasywnych zamontowanych na pakietach elektronicznych. Do badań użyto wyposażonych w magistralę układów scalonych typu STA400. Zaprezentowano metody pomiaru rezystancji pojedynczych elementów z wykorzystaniem źródła prądowego oraz źródła VH znajdującego się w analogowych modułach ABM układu STA400. Pokazano...
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Rozpoznawanie oraz lokalizacja w obrazie przewodów linii wysokiego napięcia
PublicationW pracy przedstawiono opracowany algorytm rozpoznawania oraz lokalizacji przewodów linii wysokiego napięcia na podstawie obrazu horyzontalnego. Procedura detekcji przewodu została podzielona na trzy etapy. Pierwszy etap zawiera algorytm wykrywania krawędzi wykazujący największą czułość na krawędzie poziome, a jednocześnie brak czułości na krawędzie pionowe. Efektem jest znaczna redukcja liczby wykrytych krawędzi w porównaniu do...
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Thermodynamic Cycles of Air Microturbine Power Plants Working on Biomass Fuels
PublicationThe gas turbine engine is modified to work as an air turbine set which consists, in the simplest arrangement, of a compressor, a heat exchanger and a turbine. Air is a working medium for both: the compressor and the turbine. This kind of air turbine set can be applied in power plants working on biomass fuels. In this solution we can burn fuels of varying parameters in the external combustion chamber without any harmful effects...
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New Algorithms for Adaptive Notch Smoothing
PublicationThe problem of extraction/elimination of a nonstationary complex sinusoidal signal buried in noise is considered. This problem is usually solved using adaptive notch filtering (ANF)algorithms. It is shown that accuracy of signal estimation can be increased if the results obtained from ANF are further processed using a cascade of appropriately designed filters. The resulting adaptive notch smoothing (ANS) algorithms can be employed...
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Elimination of clicks from archive speech signals using sparse autoregressive modeling
PublicationThis paper presents a new approach to elimination of impulsivedisturbances from archive speech signals. The proposedsparse autoregressive (SAR) signal representation is given ina factorized form - the model is a cascade of the so-called formantfilter and pitch filter. Such a technique has been widelyused in code-excited linear prediction (CELP) systems, as itguarantees model stability. After detection of noise pulses usinglinear...
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R&D of satellite pumps and motors with small geometrical displacement supplied with oil and non-flammable liquids
PublicationThe newest construction of satellite motors and self-suction satellite pumps with small geometrical displacement have been described in this article. The characteristics of volumetric and total efficiency of one satellite motor, selected from the series, supplied with oil have been presented. These characteristics have been compared with the orbital motors' characteristics. The remaining specifications of these motors were also...
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WSN for intelligent street lighting system
PublicationIn this article authors propose to apply WSN to intelligent street lighting system. As a result of such a combination one obtains a system designed to increase functionality of light installations for a wide range of applications and introduce a platform for new additional services, which meets current and future user needs. The system is composed of WSN nodes integrated with light sources based on high power LED diodes, which...
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Comparative analysis of numerical with optical soliton solutions of stochastic Gross–Pitaevskii equation in dispersive media
PublicationThis article deals with the stochastic Gross–Pitaevskii equation (SGPE) perturbed with multiplicative time noise. The numerical solutions of the governing model are carried out with the proposed stochastic non-standard finite difference (SNSFD) scheme. The stability of the scheme is proved by using the Von-Neumann criteria and the consistency is shown in the mean square sense. To seek exact solutions, we applied the Sardar subequation...
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T1 RELAXATION TIME CALLIBRATION IN MAGNETIC RESONANCE IMAGING USING NANODIAMOND PHANTOMS
PublicationMRI is increasingly used in radiation treatment planning because of the excellent soft tissue contrast in the obtained images. It allows more precise definition of the boundaries between healthy tissues and those affected by cancerous lesions. To obtain good image quality, the difference in signal between two types of tissue must be significant despite the noise so it must be properly calibrated. This calibration includes...
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Generalized adaptive comb filters/smoothers and their application to the identification of quasi-periodically varying systems and signals
PublicationThe problem of both causal and noncausal identification of linear stochastic systems with quasiharmonically varying parameters is considered. The quasi-harmonic description allows one to model nonsinusoidal quasi-periodic parameter changes. The proposed identification algorithms are called generalized adaptive comb filters/smoothers because in the special signal case they reduce down to adaptive comb algorithms used to enhance...
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Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths
PublicationThe sensitivity and selectivity of WO3-based gas sensors can be enhanced by UV-irradiation-induced modulation, especially if different wavelengths are employed. We used fluctuation-enhanced gas sensing, based on measurements of resistance fluctuations in the gas sensor, to study the effects of such modulation on the noise intensity for ambient atmospheres of synthetic air without and with additions of small amounts of ethanol,...
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Investigation of continuous wave jamming in an IEEE 802.15.4 network
PublicationThis paper presents how continuous wave jamming affects IEEE 802.15.4 network. To this end, an office-based measurement setup has been proposed. Within the measurement area, 25 nodes have been set up in order to create a IEEE 802.15.4 tree-based test network structure. A dedicated jamming device that generates and transmits a continuous wave signal has been developed. Several tests have been conducted and presented to demonstrate...
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Market Price Prediction of Property Rights from Gas Fired Plants or Plants with Total Installed CHP Source Capacity Below 1 MW until 2025
PublicationThe resolution on the Polish Energy Policy until 2030 (PEP-30) was adopted by the Council of Ministers on 10 November 2009. The document specifies the combined electricity and heat generation as a direction of pursuing the goals of energy efficiency, fuel and energy supply security, competitive fuel and energy markets development, and reduction of the energy sector’s environmental impact. PEP-30 assumes that electricity generation...
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Tinnitus in COVID-19 Pandemic
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Regarding the “Is Surgery an Inevitable Treatment for Advanced Salivary Lymphoepithelial Carcinoma? Three Case Reports”
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Olfactory Dysfunction in Patients With Relapsing-Remitting Multiple Sclerosis Treated With Disease-Modifying Therapies
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Recovery of Valuable Materials and Methods for Their Management When Recycling Thin-Film CdTe Photovoltaic Modules
PublicationDue to the development of new photovoltaic technologies, there is a need to research new recycling methods for these new materials. The recovery of metals from photovoltaic (PV) modules would reduce the consumption of raw materials. Therefore, the development of recycling technologies for used and damaged modules of newer generations is important for environmental reasons. The aim of the research is to shed light on the nature...
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Application of gamma densitometry and statistical signal analysis to gas phase velocity measurements in pipeline hydrotransport
PublicationThe work presents selected methods of signal analysis used in the processing of data obtained from radiometric probes. The used data came from an exemplary study of a two-phase liquid-gas flow at the laboratory installation. In such rigs many possible transport types may be observed, i.e. slug, plug and bubble flow, and each of them gives different signal-to-noise ratio of recorded data. Therefore, available radiometric methods...
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Application of gamma densitometry and statistical signal analysis to gas phase velocity measurements in pipeline hydrotransport
PublicationThe work presents selected methods of signal analysis used in the processing of data obtained from radiometric probes. The used data came from an exemplary study of a two-phase liquid-gas flow at the laboratory installation. In such rigs many possible transport types may be observed, i.e. slug, plug and bubble flow, and each of them gives different signal-to-noise ratio of recorded data. Therefore, available radiometric methods...
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Analysis of impact of lossy audio compression on the robustness of watermark embedded in the DWT domain for non-blind copyright protection
PublicationA methodology of non-blind watermarking of the audio content is proposed. The outline of audio copyright problem and motivation for practical applications are discussed. The algorithmic theory pertaining watermarking techniques is briefly introduced. The system architecture together with employed workflows for embedding and extracting the watermarks are described. The implemented approach is described and obtained results are reported....
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Application of Barkhausen effect in the impact assessment of welding to internal stress distribution in steel
PublicationThe paper presents identification method of internal stresses in plane steel elements in the chase of deliverance and welding assembly. The assessment was made by means of a non-destructive experimental method based on measurements incorporating local external magnetic field and the measurement of induced voltage, including Barkhausen noise. This method allows a degradation assessment due to internal and external actions, causing...
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Application of Barkhausen effect in the impact assessment of welding to internal stress distribution in steel
PublicationThe paper presents identification method of internal stresses in plane steel elements in the chase of deliverance and welding assembly. The assessment was made by means of a non-destructive experimental method based on measurements incorporating local external magnetic field and the measurement of induced voltage, including Barkhausen noise. This method allows a degradation assessment due to internal and external actions, causing...
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Analysis of Vibration and Acoustic Signals for Noncontact Measurement of Engine Rotation Speed
PublicationThe non-contact measurement of engine speed can be realized by analyzing engine vibration frequency. However, the vibration signal is distorted by harmonics and noise in the measurement. This paper presents a novel method for the measurement of engine rotation speed by using the cross-correlation of vibration and acoustic signals. This method can enhance the same frequency components in engine vibration and acoustic signal. After...
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Prevention of resonance oscillations in gear mechanisms using non-circular gears
PublicationOne of the main disadvantages of gear mechanisms is the occurrence of noise and vibrations. This study investigated the applicability of non-circular gears for preventing resonance oscillations in gear mechanisms. The influence of a small deviation of the gear centrodes from the nominal circles on kinematic and oscillatory characteristics was analysed. It was shown that a larger deviation results in a smaller resonance amplitude...
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Investigation of Acoustic Properties of Poroelastic Asphalt Mixtures in Laboratory and Field Conditions
PublicationMeasures for the improvement of acoustic conditions in the vicinity of roads include the construction of pavement structures with low-noise surfaces with optimal macrotexture and the highest possible sound absorption coefficient. Laboratory evaluation of acoustic properties of a designed asphalt mixture before its placement in the pavement is a good solution. Currently, the most popular method for the determination of the sound...
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UV Light-Modulated Fluctuation-Enhanced Gas Sensing by Layers of Graphene Flakes/TiO2 Nanoparticles
PublicationWe present experimental results of fluctuation-enhanced gas sensing by low-cost resistive sensors made of a mixture of graphene flakes and TiO2 nanoparticles. Both components are photocatalytic and activated by UV light. Two UV LEDs of different wavelengths (362 and 394 nm) were applied to modulate the gas sensing of the layers. Resistance noise was recorded at low frequencies, between 8 Hz and 10 kHz. The sensors’ response was...
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Modelowanie małej elektowni wiatrowej
PublicationW pracy przedstawiono model elektrowni wiatrowej o mocy 8500W wyposażonej w generator z silnikiem synchronicznym z magnesami trwałymi. W oparciu o analizę dostępnej literatury naukowej, norm technicznych, opracowano model elektrowni wiatrowej, który został zaimplementowany w środowisku Matlab Simulink. Model ten pozwala przeprowadzić analizę elektrowni wiatrowej, w której regulacja wytwarzanej energii odbywa się z wykorzystaniem...
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Synteza układu regulacji maszyny dwustronnie zasilanej zmodyfikowanego przez zastosowanie sieci neuronowej.
PublicationMaszyna dwustronnie zasilana stosowana jest jako generator w elektrowniach wiatrowych, gdzie występują bardzo ostre wymagania dotyczące jakości wytwarzanej energii elektrycznej oraz specyficzne problemy mechaniczne. Projekt dotyczy układu regulacji mocy maszyny dwustronnie zasilanej, będącej złożonym, nieliniowym obiektem, w którym mogą pojawiać się bardzo słabo tłumione oscylacje. Celem pracy było opracowanie układu regulacji...