Filters
total: 1786
filtered: 1508
displaying 1000 best results Help
Search results for: variable speed drives
-
Graphical presentation of the power of energy losses and power developed in the elements hydrostatic drive and control system. Part II. Rotational hydraulic motor speed parallel throtling control and volumetric control systems
PublicationPrzedstawiono interpretację graficzną mocy strat energetycznych występujących w elementach układów napędu i sterowania hydrostatycznego, a także mocy rozwijanych przez te elementy. Dokonano analizy układu indywidualnego ze sterowaniem dławieniowym równoległym prędkości silnika hydraulicznego obrotowego, układu indywidualnego ze sterowaniem objętościowym, pompą o zmiennej wydajności, prędkości silnika hydrailicznego obrotowego,...
-
Pulse-Width Modulation of Power Electronic DC–AC Converter
PublicationThe Second Edition of High Performance Control of AC Drives with Matlab®/Simulink delivers an updated and thorough overview of topics central to the understanding of AC motor drive systems. The book includes new material on medium voltage drives, covering state-of-the-art technologies and challenges in the industrial drive system, as well as their components, and control, current source inverter-based drives, PWM techniques for...
-
Modeling of Electrodynamic Phenomena in an Ultra-Rapid Inductive–Dynamic Actuator as Applied to Hybrid Short-Circuit Breakers - A Review Study
PublicationThis article is a study of the research development of electrodynamic phenomena occurring in ultra-fast electrodynamic drives. These types of linear drives are among the fastest, not only because of the huge accelerations achieved, but, above all, because of the extremely short reaction time. For this reason, electrodynamic drives are used in hybrid short-circuit breakers. The phenomena occurring in this type of drive are actually...
-
Five-phase Induction Motor Drive Operation During Stator Phase Fault
PublicationThe article presents the most important advantages of multi-phase electric drives. The construction of a five-phase squirrel cage induction motor together with possible stator winding distribution cases is presented, which affect the properties of such motor. Increased reliability of five-phase drives was indicated. The drive operation properties were confirmed by experimental results.
-
Speed, alcohol and safety belts as important factors influencing the number voivodship = Prędkość, alkohol i pasy bezpieczeństwa jako istotne czynniki wpływające na liczbę ofiar śmiertelnych wypadków drogowych na obszarze województw
PublicationNiniejszy referat prezentuje wyniki wstępne szerszego programu prac badawczych dotyczących bezpieczeństwa ruchu drogowego na obszarach województw.
-
Control of the wind turbine generator
PublicationWind power system consists of two main parts: wind turbine and electrical generator. Wind turbine converts the energy of the flowing air into mechanical energy, next generator converts this energy into electrical energy that is sent to the power system. These two processes should be realized with maximum efficiency and the following requirements for the control system can be formulated: opti-mal wind power conversion, compensation...
-
Current Source Inverter Fed Drive
PublicationThis book covers three-phase and multiphase (more than three-phase) motor drives including their control and practical problems faced in the field (e.g., adding LC filters in the output of a feeding converter), are considered. The new edition contains links to Matlab®/Simulink models and PowerPoint slides ideal for teaching and understanding the material contained within the book. Readers will also benefit from the inclusion of: A...
-
Multiobjective Water Distribution Systems Control of Pumping Cost, Water Quality, and Storage-Reliability Constraints
PublicationThis work describes a multiobjective model for trading-off pumping cost and water quality for water distribution systems operation. Constraints are imposed on flows and pressures, on periodical tanks operation, and on tanks storage. The methodology links the multiobjective SPEA2 algorithm with EPANET, and is applied on two example applications of increasing complexity, under extended period simulation conditions and variable energy...
-
Multi-Objective Water Distribution Systems Control of Pumping Cost, Water Quality, and Storage-Reliability Constraints
PublicationThis work describes a multi-objective model for trading-off pumping cost and water quality for water distribution systems operation. Constraints are imposed on flows and pressures, on periodical tanks operation, and on tanks storage. The methodology links the multi-objective SPEA2 algorithm with EPANET, and is applied on two example applications of increasing complexity, under extended period simulation conditions and variable...
-
Methods of measurement signal acquisition from the rotational flow meter for frequency analysis
PublicationOne of the simplest and commonly used instruments for measuring the flow of homogeneous substances is the rotational flow meter. The main part of such a device is a rotor (vane or screw) rotating at a speed which is the function of the fluid or gas flow rate. A pulse signal with a frequency proportional to the speed of the rotor is obtained at the sensor output. For measurements in dynamic conditions, a variable interval between...
-
Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych.
PublicationThis paper covers a subject of a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid). A hybrid excitation system (hybrid exciter) means a synchronous machine with wound-field and permanent magnet excitation. The hybrid exciter supply a dc field current to the synchronous generator field winding through a rotating rectifier....
-
Experimental determination of general characteristic of internal combustion engine using mobile test bench connected via Power Take-Off unit
PublicationThe general characteristics of the engine include information about the regions of the engine's operating area that are most efficient, where specific fuel consumption reaches the smallest values. Economic operation based on those characteristics can contribute to a significant reduction of fuel consumption and consequently less pollutant emissions and lower costs. The paper presents an experimental method of determination of general...
-
Road traffic can be predicted by machine learning equally effectively as by complex microscopic model
PublicationSince high-quality real data acquired from selected road sections are not always available, a traffic control solution can use data from software traffic simulators working offline. The results show that in contrast to microscopic traffic simulation, the algorithms employing neural networks can work in real-time, so they can be used, among others, to determine the speed displayed on variable message road signs. This paper describes...
-
AC motor feeding cable consequences on EMC performance of ASD
PublicationHigh level of conducted EMI emissions of adjustable speed drives (ASD) is one of the most difficult problems in contemporary applications. Many investigations are carried out in order to find more effective methods allowing to predict this emission at early stage of design, and therefore to predict adequate countermeasures. This paper deals with the method which allows to estimate by simulation the influence of motor feeding cable...
-
The adaptive backstepping control of PMSM supplied by current source inverter for the field weakening region
PublicationThe sensorless control system of permanent magnet synchronous motor PMSM supplied by current source inverter for field weakening operation is presented in this paper. The adaptive backstepping control system and the backstepping speed observer are presented. The control system is based on multi-scalar variables. The control variables are: dc-link voltage and the output current vector pulsation. The control system was named voltage...
-
Sensorless Field Oriented Control of Five Phase Induction Motor with Third Harmonic Injection
PublicationIn this paper, a sensorless field oriented control system of five-phase induction machine with the 3rd harmonic rotor flux is presented. Two vector models, α1-β1 and α3-β3, were transformed into d1-q1, d3-q3 models oriented in rotating frames, which correspond to the 1st and 3rd harmonic plane respectively. The authors proposed the linearization of the model in d-q coordinate frames by introducing a new variable “x” which is proportional...
-
Nonlinear model of a synchronous generator for analysis of more electric aircraft power systems
PublicationA nonlinear model for studying a variable-speed synchronous generator (SG) in more electric aircraft (MEA) power system has been developed. The saturation effects of the SG magnetic circuit have been considered. The model has been implemented in the Synopys/Saber simulation environment. The modelling language MAST has been used to elaborate the SG model. The model exhibit a network with the same number of external terminals/ports...
-
Compensation of pressure peaks in pwk-type hydraulic pumps
Publicationhydraulic axial pumps equipped with cam-driven commutation unit (pwk pumps) proved their high efficiency up to 55 mpa and ability to work self-sucking, even at high speed. displacement of pwk pump may easily be changed by moving its control cam. full discharge from hydrostatic forces makes such control possible by direct action of a low-energy actuator like proportional electromagnet or stepping motor. that eliminates heavy and...
-
Information System for Drivers Within the Integrated Traffic Management System - TRISTAR
PublicationAdvanced traveler information systems (ATIS) for drivers are a very important element of modern traffic management. In recent years ITS infrastructure is being developed also in Poland. It allows for delivering to drivers information related to the conditions in the road network through, inter alia, dedicated Variable Message Signs (VMS). Such information enables drivers to take decisions, contributing to improving the efficiency...
-
Impact of Low Switching-to-Fundamental Frequency Ratio on Predictive Current Control of PMSM: A simulation study
PublicationPredictive current control algorithms for permanent magnet synchronous (PMSM) drives rely on an assumption that within short intervals motor currents can be approximated with linear functions. This approximation may result either from discretizing the motor model or from simplifications applied to the continuous-time model. As the linear current approximation has been recognized as inaccurate in case when the drive operates with...
-
Variable Order Differential Models of Bone Remodelling * *This work was supported by FCT, through IDMEC, under LAETA, projects UID/EMS/50022/2013, BoneSys, joint Polish-Portuguese project Modelling and controlling cancer evolution using fractional calculus, PERSEIDS (PTDC/EMS-SIS/0642/2014) and IF/00653/2012
Publication -
Motor Cable Influence on the Conducted EMI Emission of the Converter Fed AC Motor Drive. - Vol. 1
PublicationInvestigation of conducted electromagnetic interference in AC motor drives fed by pulse width modulated voltage converters requires considering parasitic capacitances in converters, motor windings and feeding cables to be taken into account. Motor voltage transients and related conducted electromagnetic emission are significantly correlated with resonance effects occurring in load circuits. The levels of intensity of these phenomena...
-
Radio Channel Measurements in 868 MHz Off-Body Communications in a Ferry Environment
PublicationIn this paper, a characterization of the 868 MHz off-body radio channel in BANs is presented. Measurements were carried out in a ferry environment using a specific set-up. A method for path loss using radio distance measurements (RDMs) was developed. It allows to automate the measurements process and make it independent from the variable speed of a moving person. Based on the observed path loss as a function of distance, the obtained...
-
Multi-objective optimization of water quality, pumps operation, and storage sizing of water distribution systems
PublicationA multi-objective methodology utilizing the Strength Pareto Evolutionary Algorithm (SPEA2) linked to EPANET for trading-off pumping costs, water quality, and tanks sizing of water distribution systems is developed and demonstrated. The model integrates variable speed pumps for modeling the pumps operation, two water quality objectives (one based on chlorine disinfectant concentrations and one on water age), and tanks sizing cost...
-
Research of Emergency Modes of Wind Power Plants Using Computer Simulation
PublicationThe aim of this study is to investigate changes in the wind power plant energy production parameters under the conditions of sudden wind changes and voltage drop. To achieve these goals, a simulation of operation of wind power plants was performed. Twelve wind turbines with variable rotational speed equipped with a Fuhrländer FL 2500/104 asynchronous double-fed induction generator (DFIG) were used, each with an installed capacity...
-
NARAŻENIA NAPIĘCIOWE SILNIKÓW INDUKCYJNYCH ZASILANYCH Z FALOWNIKÓW NAPIĘCIA
PublicationW artykule przedstawiono zagadnienia związane z narażeniami izolacji silników pracujących w układach napędowych z falownikami napięcia. Znaczne stromości napięć oraz zjawiska falowe w przewodach zasilających powodują przyspieszoną degradacje izolacji maszyn. Rozwiązaniem jest stosowanie filtrów biernych na wyjściu falownika.
-
Ocena efektywności monitoringu obiektów inżynierskich za pomocą sieci Bayesa
PublicationW swojej pracy autorzy zaproponowali zastosowanie sieci Bayesa do projektowania monitoringu i podejmowania decyzji w działaniach eksploatacyjnych. Ponadto pokazano dwie metody oceny wartości informacji diagnostycznych. Pierwszą z nich jest wartość oczekiwana EVSI (ang. Expected Value of Sample Information), która stanowi podstawę do wyboru spośród alternatywnych obserwacji symptomów zmiennej diagnostycznej. Natomiast drugą metodą...
-
Resonant and nonresonant excitation of waves in a planar magnetosonic flow
PublicationForced propagation of perturbations in a magnetosonic wave are considered. The driving force may be caused by stimulated Mandelstam–Brillouin scattering of optic waves or by intense magnetosonic exciter. Some heating-cooling function which takes into account radiative cooling and unspecified heating is taken into consideration, as well as nonlinearity of a medium. Both these factors make the excitation particular. The analytical...
-
TOXIC GASES IDENTIFICATION USING SINGLE ELECTROCATALYTIC SENSOR RESPONSES AND ARTIFICIAL NEURAL NETWORK
PublicationThe need for precise detection of toxic gases drives development of new gas sensors structures and methods of processing the output signals from the sensors. In literature, artificial neural networks are considered as one of the most effective tool for the analysis of gas sensors or sensors arrays responses. In this paper a method of toxic gas components identification using a electrocatalytic gas sensor as a detector and an artificial...
-
Fracture Toughness and Shear Yield Strength Determination for Two Selected Species of Central European Provenance
PublicationWhen offcut of wood is formed by shearing, Atkins’s analyses of sawing processes can be applied. Using this modern approach, it is possible to determine the fracture toughness and shear yield strength of wood. This model is only applicable for the axial-perpendicular cutting direction because both of these parameters are suitable for the given direction of cutting edge movement and cannot be considered material constants. Alternatively,...
-
Optimal fractional sample delay filter with variable delay. [online] W: On- line Symposium for Electronics Engineers. Techonline Bedford, Massachu- setts, USA. [Dostęp: 15 stycznia**2002]. Dostępny w World Wide Web: http: //www.techonline.com/community/ed_resource/feature_article/14917[6 s.5 rys.] Optymalny filtr ułamkowo-opóźniający o zmiennym opóźnieniu.
PublicationW pracy zaprezentowano koncepcję filtru ułamkowo-opóźniającego o zmiennym o-późnieniu optymalnego w sensie Czebyszewa. Najpierw przedstawia jest numery-cznie wydajna metoda projektowania optymalnych filtrów ułamkowo-opóźniają-cych oparta na zespolonym algorytmie Remeza. W pracy pokazano, że można jąuprościć w przypadku projektowania filtrów ułamkowo-opóźniających. Pokazuje-my również, że jest możliwe dalsze zmniejszenie...
-
Displacement control in PWK-type pumps
PublicationThe most important, strategic goal however is creation of the variable displacement version of the new pump PWK. Thanks to full discharge of it's commutation mechanism from hydrostatic forces the variable pump can be directly controlled by low-energy actuator like proportional electromagnet or stepping motor. It means that costly and complicated hydraulic servomechanism (applied in all present variable displacement pumps) is no...
-
Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
-
Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
-
Energy Demand of Short-Range Inland Ferry with Series Hybrid Propulsion Depending on the Navigation Strategy
PublicationInterest in hybrid propulsion systems that can be used on small vessels has increased significantly in recent years. They can replace inefficient and environmentally burdensome conventional systems based on diesel engines. Hybrid propulsion has many advantages such as high energy efficiency and virtually noiseless operation, and therefore it fits well with the current trends of “green shipping” and “zero emission”. The aim of the...
-
Vertical Temperature Stratification of the Gulf of Gdansk Water
PublicationThe Baltic Sea is characterized by variable hydroacoustic conditions, which depend on hydrological conditions throughout the year. The temperature of the water is the factor that has the greatest impact on the changes in the speed of the sound in this basin. Even at a small depth, we can observe a large temperature gradient affecting the accuracy of the conducted research using hydroacoustic devices. A characteristic feature of...
-
Start-up of a power unit of a thermal power plant auxiliary systems with supply from a hydropower plant
PublicationThis article discusses the issues related to a power unit of a thermal power plant start-up with the use of a hydropower plant. Hydropower plant can supply and will enable start-up of auxiliary equipment in a power unit of a thermal power plant. Due to high capacity of auxiliary drives, start-up of auxiliaries in a thermal power plant after blackout (and boiler shutdown) is not possible from emergency energy sources in the power...
-
Autonomous Battery Drive in Trolleybuses: an Overview of Practical Examples
PublicationBattery electric buses are believed to be means of transportation of the future. However, despite the continuous development of electrochemical batteries technology and the multitude of electric buses on offer, it is still no proved solutions that can be widely used. Charging is the one of the weakness point of the electric buses. Trolleybuses are alternative for them. Especially, trolleybuses equipment with traction batteries...
-
Random field model of foundations at the example of continuous footing
PublicationThe purpose of the paper is to indicate an efficient method of foundation settlement analysis taking into account the variability of soil properties. The impact of the random variable distribution (Gauss or Lognormal) describing soil stiffness on foundation deposits was assessed. The Monte Carlo simulation method was applied in the computations. The settlements of the strip foundation with the subsoil described by a single random...
-
Monitoring of single-side lap grinding with electroplated tools
PublicationThe results presented in the paper show that utilising microphones as audible sound sensors is a suitable approach for monitoring a single-side lap grinding process due to the low levels of noise generated by the drives of a machine tool. The results confirm that sound signal analysis is a feasible and relatively simple method to monitor a lap grinding process with the use of an audible sound sensor. Proposed method can be used...
-
DYNAMIC ANALYSIS OF HISTORIC RAILWAY BRIDGES IN POLAND IN THE CONTEXT OF ADJUSTING THEM TO PENDOLINO TRAINS
PublicationThe article presents the dynamic analysis of the historic railway bridge in Tczew as an example of the usefulness of such type of bridge for high-speed trains. The model of the bridge and the simulation of rolling stock passage was performed in SOFISTIK program. The scope of work includes experimental studies, the solution of the problem concerning the correct solution features dynamic model takes into account the dependencies...
-
MACHINE VISION DETECTION OF THE CIRCULAR SAW VIBRATIONS
PublicationDynamical properties of rotating circular saw blades are crucial for both production quality and personnel safety. This paper presents a novel method for monitoring circular saw vibrations and deviations. A machine vision system uses a camera and a laser line projected on the saw’s surface to estimate vibration range. Changes of the dynamic behaviour of the saw were measured as a function of the rotational speed. The critical rotational...
-
Galerkin Finite Element Process for Entropy Production and Thermal Evaluation of Third-Grade Fluid Flow: A Thermal Case Study
Publication: A fluid’s moving class improves its heat transmission capability, as well as its rigidity, owing to multivariate molecule suspension. In this way, nanofluids are superior to common fluids. In this study, we evaluated the features of ease and heat transfer. Furthermore, we investigated permeable media, heat source, variable heat conductivity, and warm irradiation results. A mathematical technique known as the Galerkin finite element...
-
Trajectory planning for Service Ship during emergency STS transfer operation
PublicationIn this paper trajectory for approaching during emergency STS transfer operation with oil spill is considered as a sequence of navigation manoeuvres in specific navigational environment. The designed way points - ship positions and speed are determined as reference values to support navigator in decision making during steering and to mitigate the risk of collision which mostly results from exceeding the speed limit of approaching....
-
Combined thrust radial bearing of a submarine main shaft – Design and analysis of failure
PublicationThis paper presents an analysis of the combined thrust radial bearing of a submarine propulsion shaft. The lubrication system of the bearing is based on a fixed ring. The efficiency of the lubrication system depends on the shaft speed and temperature, which affects oil viscosity. In turn, the thrust bearing load also depends on the rotational speed of the shaft, because as the speed increases, the drag of the ship increases simultaneously,...
-
Towards Universal Visualisation of Emotional States for Information Systems
PublicationThe paper concerns affective information systems that represent and visualize human emotional states. The goal of the study was to find typical representations of discrete and dimensional emotion models in terms of color, size, speed, shape, and animation type. A total of 419 participants were asked about their preferences for emotion visualization. We found that color, speed, and size correlated with selected discrete emotion...
-
Theoretical and Actual Feed Per Tooth During Wood Sawing on an Optimizing Cross-Cut Saw
PublicationThe work presents the geometries of circular saw teeth, whose task is to divide the cross-cut of the cutting layer. For efficient machining on a cross-cut saw with high feed speed values (about 1 ms−1) maximal theoretical feeds per tooth are determined. These values were compared with the actual values determined during transverse cutting of pine wood on a special test stands in industrial conditions. In the experiment the rotational...
-
Niekorzystny wpływ przekształtnikowego zasilania PWM na silniki asynchroniczne trakcyjne
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...
-
Destructive impact of PWM inverters on traction AC motors
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings's increased voltage exposure and...
-
Destructive Consequences of PWM Inverter Feeding for Traction AC Motors
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...