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Search results for: POWER SYSTEMS
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Driving a new perspective Professor Zygmunt Paszota, faculty of ocean engineering and ship technology, Gdansk University of Technology, Poland, explains a new approach to the Sankey Diagram for drive motors
PublicationThe paper presents the necessity of replacing the traditional, commonly accepted but erroneous, Sankey diagram of power decrease in the direction of power flow by the diagram, proposed by the Author, of power increase in the direction opposite to the direction of power flow. The proposed view of losses and energy efficiency should be applied to all types of drive motors and drive systems. The presented proposals open a new perspective...
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Compensation of Dead Time Effects for Shunt Active Power Filters
PublicationThe paper presents a comprehensive approach to the compensation of the grid current distortion for shunt active power filter systems. Four different sources of current distortion are addressed: imperfect grid synchronization caused by the distortion in the grid voltages, time delays in the estimation of compensating currents and grid voltages, fluctuations of the dc bus voltage, and the distortion of inverter output voltages due...
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Comparative analysis of thermodynamic cycles of selected nuclear ship power plants with high-temperature helium-cooled nuclear reactor
PublicationThis paper presents a comparative analysis of thermodynamic cycles of two ship power plant systems with a high-temperature helium- cooled nuclear reactor. The first of them is a gas system with recuperator , in which classical gas chamber is substituted for a HTGR reactor (High Temperature Gas-cooled Reactor) . The second of the considered cycles is a combined gas-steam system where working medium flux from gas turbine outlet...
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Models of Brushless Synchronous Generator for Studying Autonomous Electrical Power System
PublicationThis is a PhD dissertation. The work presented in this monograph was carried out at the Department of Power Electronics and Electrical Machines, Faculty of Electrical and Control Engineering at the Gdansk University of Technology. Developed during the research models of brushless synchronous generator ware verified using FEM based simulations and measurements conducted on the prototype generator. The main focus of the research...
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Advancing Solar Energy: Machine Learning Approaches for Predicting Photovoltaic Power Output
PublicationThis research is primarily concentrated on predicting the output of photovoitaic power, an essential field in the study of renewable energy. The paper comprehensively reviews various forecasting methodologies, transitioning from conventional physical and statistical methods to advanced machine learning (ML) techniques. A significant shift has been observed from traditional point forecasting to machine learning-based forecasting...
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Risk of power cables insulation failure due to the thermal effect of solar radiation
PublicationLow-voltage, as well as high-voltage power cable lines, are usually buried in the ground. The ampacity of the power cables in the ground mainly depends on the thermal resistivity of the soil, which may vary in a wide range. A common practice in power cable systems performance is to supply them from a pole of an overhead line. If so, a section of the line is located in free air and can be directly exposed to solar radiation. In...
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Engineering education for smart grid systems in the quasi-industrial environment of the LINTE^2 laboratory
PublicationSmart grid systems are revolutionising the electric power sector, integrating advanced technologies to enhance efficiency, reliability and sustainability. It is important for higher education to equip the prospective smart grid professional with the competencies enabling them to navigate through the related complexities and drive innovation. To achieve this, interdisciplinary education programmes are necessary, addressing inter...
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Influence of Different Biofuels on the Efficiency of Gas Turbine Cycles for Prosumer and Distributed Energy Power Plants
PublicationThe efficiency of a gas turbine can be affected by the use of different biofuels usually with a relatively Lower Heating Value (LHV). The paper evaluates the impact of calorific value of fuel on turbine performance and analyzes the possibilities of optimizing turbine construction from the point of view of maximum efficiency for a particular fuel. The several variants of design of small power microturbines dedicated to various biofuels...
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Studies of the Modelling Accuracy of Steam Turbine Control Systems for Diagnostic Tests of Automatic Synchronizers
PublicationOne of the important factors that affect the reliable operation of the power system and the rapid restitution after disaster is a quick and effective combining synchronous electric power facilities to operate in parallel. Hence, diagnostics of automatic synchronizers at every stage of their life, from building a prototype, through the whole life, until removing such devices from the operation, is an extremely important and responsible...
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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
PublicationPaper 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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Optimization issues in distributed computing systems design
PublicationIn recent years, we observe a growing interest focused on distributed computing systems. Both industry and academia require increasing computational power to process and analyze large amount of data, including significant areas like analysis of medical data, earthquake, or weather forecast. Since distributed computing systems – similar to computer networks – are vulnerable to failures, survivability mechanisms are indispensable...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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Comprehensive compensation of grid current distortion by shunt active power filters
PublicationThe paper presents a comprehensive approach to the compensation of grid current distortion in shunt active power filter systems. Four sources of current distortion are addressed: imperfect grid synchronization caused by the distortion in the grid voltages, time delays in the evaluation of grid voltages and computation of compensating currents, fluctuations of the dc bus voltage, and the distortion of inverter output voltages due...
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Air Power History
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Journal of Political Power
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Propulsion and Power Research
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Power System Technology
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Wireless Power Transfer
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Advances in Power Electronics
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Journal of Power Electronics
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JOURNAL OF PROPULSION AND POWER
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Power Generation Technology
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Evaluation of VSC Impact on Power System Using Adequate P-Q Capability Curve
PublicationRenewable energy sources, which are becoming increasingly popular, often use a voltage source converter (VSC) for connection to the power system. Assessing the effects of connecting such a source to the power system is essential to ensure the proper operation of the power system and the connected source. For this purpose, it is necessary to know the range of active and reactive power generation by the converter. The authors indicate...
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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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Research of electric drive systems with real time software configurable control
PublicationПредмет исследования. Представлен учебно-лабораторный стенд для исследования систем управления элек- троприводами. Стенд используется для обучения студентов системам управления электроприводами и предна- значен для повышения эффективности усвоения материала. Метод. В основу предлагаемого решения положен метод взаимного нагружения электрических машин, питаемых от силовых преобразователей с общим звеном постоянного тока. Это позволяет...
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High Frequency Harmonics Emission of Modern Power Electronic AC-DC Converters
PublicationModern AC/DC converters with bidirectional power flow employing PWM boost topology generate harmonic distortions of input current in relatively high frequency range tightly related to modulation carrier frequency. These frequencies and its multiples in typical applications are usually located in frequency range from single up to several of kHz. Increased harmonic emission in this frequency range can easily and harmfully influence...
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Assessment of protective properties of rubber lining in absorbers of flue gas desulphurization systems.
PublicationResults of research on degradation of rubber lining which is the main protection of absorbers in flue gas desulphurization (FGD) systems were presented. The power plant where the system operated is lignite-fired. Owing to measurements using electrochemical impedance spectroscopy and gravimetric determination of water content in the lining, the areas of the system which are most exposed to degradation were shown. The results obtained...
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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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The excitation controller with gain scheduling mechanism for synchronous generator control
PublicationThe power systems, including the synchronous generators and power systems networks, are complex nonlinear systems with configuration and parameters which change through time. That leads to electromechanical oscillations occurring in that system. Thus synchronous generator excitation controller must be capable of providing appropriate stabilization signal over broad range of operating conditions and disturbances. In this paper,...
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Mathematical Models of Control Systems of Angular Speed of Steam Turbines for Diagnostic Tests of Automatic and Mechatronic Devices
PublicationAccurate modeling of physical processes of many automatics and mechatronics systems is often necessity. In power system such a process is control of angular velocity of power objects during connection to operation in parallel. This process is extremely dynamic. For this reason response of control system depends from changes of many physical parameters (temperature, pressure and flow of the medium, etc.). Precision modeling influences...
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Energy Router: A Sustainable Solution for Future Residential Buildings
PublicationElectric energy consumption is increasing much faster than the predicted growth in energy generation. Although the installed capacity of renewable energy sources is also expanding, grid congestion remains unavoidable without adopting smart energy management systems (EMS) and flexible power electronics structures. Given the significant installed capacity of photovoltaic (PV) systems in the residential sector, moving towards zero-emission...
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Prototype design and development of low-load-roof photovoltaic modules for applications in on-grid systems
PublicationFour prototypes of lightweight photovoltaic modules for applications in on-grid systems have been designed, developed, manufactured and tested for compliance with relevant IEC standards. Selected, commercially available materials characterized by thermogravimetry, differential scanning calorimetry, dilatometry, scanning electron microscopy and nanoindentation technique were used in frameless, adhesively-bonded sandwich-structures...
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High-efficiency mini and micro heat exchangers for dispersed power generation
PublicationTaking into account the dispersed systems technologies and their development, the ORC systems seem to be promising technology amongst various micro-CHP domestic units (electrical power production below 10 kWe), however practical realization of the ORC cycle in a micro-scale is technically challenging. The system consists in devices such as the vapour generation unit (boiler), expansion device and heat exchangers. Each of them should...
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Monitoring Regenerative Heat Exchanger in Steam Power Plant by Making Use of the Recurrent Neural Network
PublicationArtificial Intelligence algorithms are being increasingly used in industrial applications. Their important function is to support operation of diagnostic systems. This paper pesents a new approach to the monitoring of a regenerative heat exchanger in a steam power plant, which is based on a specific use of the Recurrent Neural Network (RNN). The proposed approach was tested using real data. This approach can be easily adapted to...
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Investigation of Performance and Energy Consumption of Tokenization Algorithms on Multi-core CPUs Under Power Capping
PublicationIn this paper we investigate performance-energy optimization of tokenizer algorithm training using power capping. We focus on parallel, multi-threaded implementations of Byte Pair Encoding (BPE), Unigram, WordPiece, and WordLevel run on two systems with different multi-core CPUs: Intel Xeon 6130 and desktop Intel i7-13700K. We analyze execution times and energy consumption for various numbers of threads and various power caps and...
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VSC converters control for offshore wind farms HVDC grid connection
PublicationThe paper proposes a voltage sourced converter (VSC) new control method. A well-known in the electric power systems correlation between voltage angle and active power and correlation between voltage and reactive power is used instead of feedforward control. This allows for a fast and almost independent control of active and reactive power flow.
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Performance and Energy Aware Training of a Deep Neural Network in a Multi-GPU Environment with Power Capping
PublicationIn this paper we demonstrate that it is possible to obtain considerable improvement of performance and energy aware metrics for training of deep neural networks using a modern parallel multi-GPU system, by enforcing selected, non-default power caps on the GPUs. We measure the power and energy consumption of the whole node using a professional, certified hardware power meter. For a high performance workstation with 8 GPUs, we were...
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Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
PublicationThe paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number...
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50’ Sail Catamaran with Hybrid Propulsion, Design, Theoretical and Experimental Studies
PublicationThe development of modern lithium batteries and propulsion systems now allows the use of complex propulsion systems for vessels of various sizes. As part of the research and implementation project, a parallel hybrid drive system was designed, built and then tested in the laboratory. The experimental studies conducted allowed for the measurements of power, fuel consumption and electric power distribution in various operating modes...
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The Influence of Limiters UEL and OEL (The power angle, stator's current and excitation current) ot the possibility of voltage collapse development
PublicationVoltage stability has been a major concern for power system utilities because of event of voltage collapses in the recent past. Sometimes, power system events have shown the need for generators to operate in the overexcited and underexcited region to support stable operation. Modern excitation systems include devices for controlling or limiting machine terminal voltage (overvoltage limiters), volts per hertz ratio (V/Hz limiters),...
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Energy-Aware High-Performance Computing: Survey of State-of-the-Art Tools, Techniques, and Environments
PublicationThe paper presents state of the art of energy-aware high-performance computing (HPC), in particular identification and classification of approaches by system and device types, optimization metrics, and energy/power control methods. System types include single device, clusters, grids, and clouds while considered device types include CPUs, GPUs, multiprocessor, and hybrid systems. Optimization goals include various combinations of...
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Smart Embedded Systems with Decisional DNA Knowledge Representation
PublicationEmbedded systems have been in use since the 1970s. For most of their history embedded systems were seen simply as small computers designed to accomplish one or a few dedicated functions; and they were usually working under limited resources i.e. limited computing power, limited memories, and limited energy sources. As such, embedded systems have not drawn much attention from researchers, especially from those in the artificial...
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Current divider-based nanosecond high current pulse measuring systems
PublicationThis paper presents the analysis of the new approach to the measurement methodology of significant values (in order of hundreds of kA) and huge steepness (in order of MA/μs) current pulses based on current dividers along with a comparison of the various types transducers suitability in measuring systems with such extreme parameters. Such dividers are used to extend the measurement ranges of current transducers with limited current...
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Teaching High–performance Computing Systems – A Case Study with Parallel Programming APIs: MPI, OpenMP and CUDA
PublicationHigh performance computing (HPC) education has become essential in recent years, especially that parallel computing on high performance computing systems enables modern machine learning models to grow in scale. This significant increase in the computational power of modern supercomputers relies on a large number of cores in modern CPUs and GPUs. As a consequence, parallel program development based on parallel thinking has become...
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Simulating Power Generation from Photovoltaics in the Polish Power System Based on Ground Meteorological Measurements—First Tests Based on Transmission System Operator Data
PublicationThe Polish power system is undergoing a slow process of transformation from coal to one that is renewables dominated. Although coal will remain a fundamental fuel in the coming years, the recent upsurge in installed capacity of photovoltaic (PV) systems should draw significant attention. Owning to the fact that the Polish Transmission System Operator recently published the PV hourly generation time series in this article, we aim...
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Determination of Mechanical Energy Loss in Steady Flow by Means of Dissipation Power
PublicationWhen systems of simple geometry like pipes or regular channels are considered, the mechan- ical energy loss of the fluid flow can be expressed by local and longitudinal empirical energy loss coefficients. However, in the case of large spatially distributed objects, there are no simple approaches to this task. In practice, general recommendations addressing different types of objects are used, but they usually provide very coarse...
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Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublicationThe modern concept of a universal converter is intended as a power converter suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow an easier integration of renewable energy sources and energy storage systems, interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and applications...
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Dielectric Barrier Discharge Systems with HV Generators and Discharge Chambers for Surface Treatment and Decontamination of Organic Products
PublicationThe 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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Behavior of residual current devices at earth fault currents with DC component
PublicationLow-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...