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Search results for: customer-side resources interconnection , single phase vapf , voltage active power filter , power electronics converter , energy cost reduction
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Analysis of possible application of high-temperature nuclear reactors to contemporary large-output steam power plants on ships
PublicationThis paper is aimed at analysis of possible application of helium to cooling high-temperature nuclear reactor to be used for generating steam in contemporary ship steam-turbine power plants of a large output with taking into account in particular variable operational parameters. In the first part of the paper types of contemporary ship power plants are presented. Features of today applied PWR reactors and proposed HTR reactors...
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Multipulse inverter structures with low voltage distortion
PublicationA novel approach to the voltage source inverters (VSI) construction is presented in the paper. The invented inverter structures allow to operate several DC/AC converters in parallel resulting in lower voltage distortions at extremely low switching frequency. The research presented in the paper describes such a parallel operation of the VSI’s which is possible thanks to the use of coupled inductors. The eighteen-pulse three-level...
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Energy-Aware Scheduling for High-Performance Computing Systems: A Survey
PublicationHigh-performance computing (HPC), according to its name, is traditionally oriented toward performance, especially the execution time and scalability of the computations. However, due to the high cost and environmental issues, energy consumption has already become a very important factor that needs to be considered. The paper presents a survey of energy-aware scheduling methods used in a modern HPC environment, starting with the...
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Simplified saturation modelling in three-leg power transformer for the system stability analisys
PublicationThe paper presents a simplified method for modelling non-linearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The transformer model is described...
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The project of pull system for storehouse and production line in a company provides electronics
PublicationThe chapter below presents how to reduced delivery of the material to production by using a "Kanban schedule board" and related tools from 48 hours and 59 minutes to 41 minutes in a company provides electronics. The solution was found through analysis of the current way of supplying stands and using Just In Time idea, the reduction of ''muda''. To solve the problem was used Kanban card", which has the shape of two triangles joined...
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The extended model predictive-sliding mode control of three-level AC/DC power converters with output voltage and load resistance variations
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Secondary arc modelling for single pole reclosing analyses
PublicationThe paper discusses two evaluation methods of single pole auto-reclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage calculation results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a nonlinear secondary arc model implementation is presented. The paper presents the study results for the three types of EHV transmission...
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Winding function approach based design of novel five-phase brushless doubly fed induction generator
PublicationThe paper presents the concept of the new design of the five-phase brushless doubly fed induction generator. The generator is dedicated to the modern wind turbine. The innovative design approach uses a five-phase power supply from the stator control winding side of the generator with a stator three-phase classic power winding. The research results presented indicate that the electromagnetic coupling between the control and power...
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Revisiting The Determination Of Cutting Power While Sawing Of Wood With Circular Saw Blades By Means Of Fracture Mechanics
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, cutting forces (power) could be considered from a point of view of modern fracture mechanics. Cutting forces may be employed to determine not only toughness...
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Degree of monopoly and market power vs. price flexibility in Polish economy: empirical analysis based on COICOP classification
PublicationResearch background: The issue of price flexibility is crucial in the economy both in the aspect of company theory and its macroeconomic consequences. In a number of publications, the sources of variable price flexibility are linked to the market power of enterprises as well as the market structure that has developed in a given branch. It is difficult to indicate empirical studies that would state clearly whether price flexibility...
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Non-isolated resonant quasi-Z-source network DC–DC converter
PublicationA novel non-isolated resonant quasi-impedance (quasi-Z)-source network DC–DC converter is proposed. The resonant impedance source network is derived from the quasi-Z-source network by including the autotransformer-based resonant cell instead of the second inductor of the quasi-Z-network. The leakage inductance of the autotransformer and two resonant capacitors connected in series with the autotransformer windings constitute a high-frequency...
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Photovoltaic maximum power point varying with illumination and temperature
PublicationW pracy przedstawiono wyniki badań eksperymentalnych zmian położenia punktu maksymalnej mocy na charakterystyce prądowo-napięciowej modułu ogniw fotowoltaicznych, związanych ze zmieniającą się temperaturą i natężeniem padającego promieniowania. Badano czas narastania napięcia pracy i temperatury ogniw w początkowej fazie ekspozycji na promieniowanie słoneczne. Przedstawiono niektóre praktyczne aspekty zastosowania układu automatycznego...
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The QDMC Model Predictive Controller for the Nuclear Power Plant Steam Turbine Control
PublicationThere are typically two main control loops with PI con trollers operating at each turbo-generator set. In this paper a model predictive controller QDMC for the steam turbine is proposed - instead of a typical PI controller. The QDMC controller utilize a step-response model for the controlled system. This model parameters are determined, based on the simplified and linear model of turbo-generator set, which parameters are identified...
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New Insights into Dietary Supplements Used in Sport: Active Substances, Pharmacological and Side Effects
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Design and Implementation of a Dual-band Filtering Wil-kinson Power Divider Using Coupled T-shaped Dual-band Resonators
PublicationThe paper introduces a novel structure of a dual-band filtering Wilkinson power divider (WPD). Its essential component is a dual-band bandpass filter (BPF), implemented using coupling lines and two T-shaped resonators. The BPF is incorporated into the divider structure to suppress the unwanted harmonics within the circuit. The latter is achieved owing to a wide stopband of the filter. The deigned dual-band WPD can suppress third...
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Fault detection and diagnostics of complex dynamic systems using Gaussian Process Models - nuclear power plant case study
PublicationThe 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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Empirical analysis of tree-based classification models for customer churn prediction
PublicationCustomer churn is a vital and reoccurring problem facing most business industries, particularly the telecommunications industry. Considering the fierce competition among telecommunications firms and the high expenses of attracting and gaining new subscribers, keeping existing loyal subscribers becomes crucial. Early prediction of disgruntled subscribers can assist telecommunications firms in identifying the reasons for churn and...
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The Concept of a Methodology for Selecting the Optimal Parameters of Heat Received from a Nuclear Power Plant Operating in a Partial Cogeneration Mode
PublicationThe paper presents the concept of the objective function which is to allow the selection of optimal parameters of the district heating system using a nuclear power plant operating in partial cogeneration mode. The concept is based on research carried out a number of years ago. The size of annual expenses was proposed as the objective function, which allows to compare the operation of a nuclear power plant in partial cogeneration...
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Design advantages and analysis of a novel five-phase doubly-fed induction generator
PublicationPurpose – The purpose of this paper is to provide an analysis of the performance of a new five-phase doubly fed induction generator (DFIG). Design/methodology/approach – This paper presents the results of a research work related to fivephase DFIG framing, including the development of an analytical model, FEM analysis as well as the results of laboratory tests of the prototype. The proposed behavioral level analytical model is based...
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Diagnosis of bearing damage in induction motors by instantaneous power analysis
PublicationResearch of the machine with simulated bearing damages has been carried out, where variable load torque, simulating bearing damage, was introduced. The results show that components which can be used for bearings diagnosis appear in the spectrum of the product of current and supply voltage instantaneous values. These components are easier to identify than the components of current spectrum, which have been used so far in diagnostic...
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Fuzzy Based Maximum Power Point Tracking (MPPT) Control System for Photovoltaic Power Generation System
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Optimization of Graphene Oxide Synthesis and Its Reduction
PublicationIn this article, we present the review of the chemical methods of synthesis of graphene oxide and its reduction in order to obtain the so-called reduced graphene oxide (rGO) whose properties are similar to those of pure graphene. We also present our experiments and the results in this field and the comparison of the efficiency of different methods of synthesis as well as the reduction of graphene oxide. To characterize the obtained...
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Comparison analysis of selected nuclear power plants supplied with helium from high-temperature gas-cooled reactor
PublicationThe article presents results of efficiency calculations for two 560 MW nuclear cycles with high-temperature gas-cooled reactor (HTGR). An assumption was made that systems of this type can be used in so-called marine nuclear power plants. The first analysed system is the nuclear steam power plant. For the steam cycle, the efficiency calculations were performed with the code DIAGAR, which is dedicated for analysing this type of systems....
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Predicting cutting power for band sawing process of pine and beech wood dried with the use of four different methods
PublicationWood drying is an important stage in the woodworking process. After drying, wood is subject to a re-sawing process, for which a high quality surface, low material loss, and high efficiency are often required. In this paper, forecasted values were presented of cutting power for the re-sawing process of pine and beech wood that were dried with four different methods. Forecasting of cutting power for an industrial band saw machine...
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Credibility of Business Operations via Internet: Customer Perspective
PublicationTourism plays an important role in economy of Mediterranean countries. Year after year, more and more people spend or like to spend their vacations (and money) in the Mediterranean region. Hiring private apartments or houses by individual persons for themselves and their families becomes more and more popular way of vacation arrangement and, in the result, constitutes an important factor of the countries' incomes. Versatile and...
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Optimization of hybrid parallel application execution in heterogeneous high performance computing systems considering execution time and power consumption
PublicationMany important computational problems require utilization of high performance computing (HPC) systems that consist of multi-level structures combining higher and higher numbers of devices with various characteristics. Utilizing full power of such systems requires programming parallel applications that are hybrid in two meanings: they can utilize parallelism on multiple levels at the same time and combine together programming interfaces...
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Simulation of the Remanence Influence on the Transient States of the Single-Phase Transformer Including Feedback Preisach Model
PublicationThis paper presents the results of the experimental and simulation investigation concerning the influence of remanence in the core of a single-phase transformer at the no-load transient state. Experimental studies consisted of the discharge of the capacitor through the primary winding at several different values of the residual magnetic flux. The paper presents a model of the transformer test system, taking into account the magnetic...
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Modelling Of Commercial Websites. A New Perspective On Usability And Customer Relation
PublicationFrom an economic point of view, a critical aspect of online services is their ability to retain customers. The aim of presented study was the use of a layered model VIPR (Visual - Interaction - Process - Relation ) for commercial services online. The indicator of trust and establishing lasting relationships were assessment achieved from experienced users of commercial online services (n = 207), obtained by means of Web Credibility...
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Accuracy of a low-cost autonomous hexacopter platforms navigation module for a photogrammetric and environmental measurements
PublicationA photogrammetry and environmental measurements from an unmanned aerial vehicle (UAV) are a low-cost alternative for a traditional aerial photogrammetry. A commercial off-the-shelf products (COTS) offers a variety of cheap components that a suitable to be used on board a UAV. In this paper a low-cost navigation module based on Ublox NEO-M8N GPS and Pixhawk flight controller have been described, as a main extrinsic parameters source...
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Small hydro-power in the European Union
PublicationW pracy przedstawiono informacje na temat udziału energii odnawialnej w produkcji energii w świecie oraz udziału odnawialnych źródeł energii (OZE) w 25 krajach Unii Europejskiej w roku 1997 i przewidywany udział w roku 2010. Omówiono historię rozwoju małych elektrowni wodnych (MEW) w Unii Europejskiej i dokonano ogólnego przeglądu MEW w krajach UE i w pozostałych krajach Europy. Przedstawiono możliwy rozwój małej energetyki wodnej...
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The laboratory model of wind power generator
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Pumped-storage power plant Żarnowiec.
PublicationPrzedstawiono historię budowy, główne zadania i parametry techniczne elektrowni szczytowo-pompowej w Żarnowcu
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Neural simulator of steam power unit.
PublicationZbadano możliwości zbudowania neuronowego symulatora turbinowego bloku energetycznego. Zamodelowano ten obieg i sprawdzono konfiguracje sztucznych sieci neuronowych (SSN) zapewniające dużą dokładność symulatora neuronowego. Zwrócono uwagę na problemy dotyczące węzłów siłowni, w których następuje mieszanie się strumieni czynnika o zróżnicowanych parametrach cieplno-przepływowych. Wskazano na zastosowanie takiego symulatora w diagnostyce.
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Hydraulic power plant on the Radunia River
Publicationprzedstawiono rys historyczny, paramerty techniczne i walory turystyczne elektorwni wodnych.
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Voltage Dependence of Supercapacitor Capacitance
PublicationElectronic Double-Layer Capacitors (EDLC), called Supercapacitors (SC), are electronic devices that are capable to store a relatively high amount of energy in a small volume comparing to other types of capacitors. They are composed of an activated carbon layer and electrolyte solution. The charge is stored on electrodes, forming the Helmholtz layer, and in electrolyte. The capacitance of supercapacitor is voltage- dependent. We...
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Can Communication Power of Separable Correlations Exceed That of Entanglement Resource?
PublicationThe scenario of remote state preparation with a shared correlated quantum state and one bit of forward communication [B. Dakić et al., Nat. Phys. 8, 666 (2012)] is considered. Optimization of the transmission efficiency is extended to include general encoding and decoding strategies. The importance of the use of linear fidelity is recognized. It is shown that separable states cannot exceed the efficiency of entangled states by...
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Limiting distribution of the three-state semi-Markov model of technical state transitions of ship power plant machines and its applicability in operational decision-making.
PublicationThe article presents the three-state semi-Markov model of the process {W(t): t 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application...
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Direct-contact condensation from vapour- gas mixture in a spray ejector condenser for negative CO2 power plant
PublicationDirect-contact condensation of vapour containing the inert gas on a spray of subcooled liquid exists in a number of technical applications. For example, it may be found in the nuclear industry (e.g. pressurized jet under normal operating conditions, in safety analyses) or in the chemical industry (e.g. mixing-type heat exchanger, degasser, sea water desalting). The problem is also essential to modelling and analysis of some...
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Defence in depth conception in nuclear power plants and requirements for instrumentation and control systems
PublicationThe aim of this article is to identify and discuss some issues of the safety systems’ design for nuclear power plants equipped with the light water reactors using a defence in depth (D-in-D) conception. Because the functional safety solutions play nowadays an important role for the risk control, the basic requirements for the instrumentation and control systems are specified with regard to relevant international standards. For...
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Sensorless control system of induction machine supplied by voltage source inverter with output filter
PublicationThe paper focuses on sensorless control of the induction machines supplied by inverter with the output filters. “The novel” idea of the speed observer which is based on the backstepping approach is shown. The standard structure of the exponential observer is extended by the integrators and additional Z vector. The simulation and experimental results validate the proposed solution.
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DIRECTIONS OF THE SCIENTIFIC RESEARCH CONDUCTED IN THE DEPARTMENT OF MARINE AND POWER PLANTS OF THE FACULTY OF OCEAN ENGINEERING AND SHIP TECHNOLOGY OF THE GDANSK UNIVERSITY OF TECHNOLOGY
PublicationIn this article the short historical outline of the Department of Marine and Land Power Plants of the Faculty of Ocean Engineering and Ship Technology of the Gdansk University of Technology was introduced. Its activity beginnings, in the post-war history of the University, reach 1952. The leading scientific issues, which have been developed for years in three principal directions: design, manufacture and operation of machines and...
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Continuous-Time Active-RC Filter Model for Computer-Aided Design and Optimization
PublicationW pracy przedstawiono ogólny model filtru aktywnego RC opartego na wzmacniaczach odwracajacych faze. Model analizowany jest przy użyciu równań macierzowych. Podano jawną formułę określającą funkcję przenoszenia filtru w ogólnym przypadku. Przedstawiono rozszerzenia modelu pozwalające uwzgledniać nieidealność wzmacniaczy operacyjnych, w tym skończone wzmocnienie i pasmo przenoszenia oraz niezerową rezystancję wyjściową. Wyprowadzono...
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Technology and Energy Conversion Machines - Nowy
e-Learning CoursesThe course covers the basics of mechanical, electrical and thermal energy production in industry and maritime transport. Describes installations supporting high-power engines. Particular attention has been paid to the fuel systems of internal combustion engines. The treatment of engine exhaust gases is described.
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Voltage Harmonic Distortion Measurement Issue in Smart-Grid Distribution System
PublicationThis paper presents the investigation results ofvoltage harmonic transfer accuracy problems through voltagetransformers which are widely used in power quality monitoringsystems in medium and high voltage grids. A simplified lumpedparameters circuit model of the voltage transformer is presentedand verified by simulation and experimental investigations. Anumber voltage transformers typically used in medium voltagegrid has been tested...
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Active vibration reduction with a use of enegry performance index at acceleration feedback
PublicationW pracy przedstawiono wyniki badań eksperymentalnych i symulacji w trybie Hardware-in-the-loop nowego algorytmu aktywnej redukcji drgań. Algorytm ten bazuje na energetycznym wskaźniku jakości zmodyfikowanym w ten sposób, że wykorzystuje bezpośrednio sygnał sprzężenia zwrotnego przyspieszeń.
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Energy Systems Stations, PG_00042106, W, PE-ET, sem.7, winter 2023/24
e-Learning CoursesConstruction and operation of energy systems, based on the example of the ship power plant.
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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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Comparative Analysis of Salient and Non-Salient Pole Brushless Synchronous Generator for Application in Autonomous Electric Power System
PublicationThis paper presents a comparative study of two types of brushless synchronous generator for application in autonomous electric power systems (e.g. airplane power grid). Commercially used salient pole and a prototype non-salient pole high speed multi-pole brushless synchronous generator (BSG) have been presented. Comparative analysis of both types of the generator has been performed. Chosen simulation (using FEM and circuit models)...
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Nicole Nawrot dr inż.
PeopleDr. Eng. Nicole Nawrot has been employed at the Department of Sanitary Engineering since 2016. In 2021, she obtained a PhD in the field of engineering and technical sciences in the discipline of environmental engineering, mining and energy. Doctoral thesis entitled "Heavy metals in urban retention tanks bottom sediments: distribution, source tracking, and evaluation of phytostabilization adaptability and performance of P. australis...
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Space Vector Pulsewidth Modulation Strategy for Multilevel Cascaded H-Bridge Inverter With DC-Link Voltage Balancing Ability
PublicationSpace vector pulsewidth modulation (SVPWM) algorithms for cascaded H-bridge multilevel (CHB ML) inverter usually provide the possibility of using several combinations of active voltage vectors to generate the same output voltage vector. For preselected H-bridges, some of them may generate output voltages opposite to the assumed direction. This results in the change of the dc-link voltages of these H-bridges in the opposite direction...