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Search results for: LOW-VOLTAGE NETWORK
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Using A Particular Sampling Method for Impedance Measurement
PublicationThe paper presents an impedance measurement method using a particular sampling method which is an alternative to DFT calculation. The method uses a sine excitation signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance is calculated without using Fourier transform. The method was first evaluated in MATLAB by means of simulation. The method was...
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Effect of underwater local cavity welding method conditions on diffusible hydrogen content in deposited metal
PublicationOne of the methods with great potential for applications in underwater repairs is local cavity welding. In local cavity method, cooling conditions and diffusible hydrogen amount in weld metal are nearly the same as those existed during welding in the air. This paper presents the results of literature survey and preliminary tests of the effect of local cavity welding conditions on diffusible hydrogen amount in a deposited metal....
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Al-DIAMOND SCHOTTKY TUNNEL DIODES WITH BARRIER HEIGHT CONTROL
PublicationFew-nanometer-thick very highly boron-doped p-type layers were fabricated at metal-semiconductor interfaces of Schottky barrier diodes formed with aluminum on polycrystalline diamond. Preliminary results show that hermionically-assisted tunneling mechanism results in lower voltage drops at forward biasing of these diodes than expected for the Al-diamond metal-semiconductor potential barrier B. The effective barrier height Bpeff...
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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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Remote current measurement with FPGA digital processing
PublicationThe work presents an implementation of a modular measurement and control systemthat controls variants of mains supply of 230V electrical equipment. The system allowsto supervise power consumption in the office electronic equipment. The system detectsthe instant of the reduced power consumption by a device and makes possible itsswitch-off in order to reduce energy cost. The current is measured with integratedcurrent/voltage converters....
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Assesment of (Mn,Co)3O4powders for possible coating material for SOFC/SOEC interconnects
PublicationIn this work (Mn,Co)3O4 spinel powders with different Mn:Co ratio (1:1 and 1:2) and from different commercial suppliers are evaluated for possible powder for production of interconnect coatings. Sinterability of the powders is evaluated on pressed pellets sintered in oxidizing and in reducing/oxidizing atmospheres. For selected powder, coatings are then prepared by the electrophoretic deposition method on Crofer 22 APU stainless...
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EHV transmission lines wires location on line operation issues - case studies
PublicationTransmission lines towers construction affects the line parameters and influences on its operation in the future. Misguided design of the tower can lead to serious problems such as overvoltages, electric arc extinction difficulties, voltage asymmetry, resonance phenomena or increasing of magnetic field near the line. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors....
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Wireless Charging Station Design for Electric Scooters: Case Study Analysis
PublicationThis study proposes an example of a wireless charging station design for a small-scale vehicle available on the market. The article analyzes basic transmitter inverter topologies and their compensation methods in terms of flexibility of control, tolerance to uncertainty in positioning, and the possibility of decreasing the integration price. Our comprehensive analysis focuses on the battery voltage range, energy capacity, cost,...
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Software Agents for Computer Network Security
PublicationThe chapter presents applications of multi-agent technology for design and implementation of agent-based systems intended to cooperatively solve several critical tasks in the area of computer network security. These systems are Agent-based Generator of Computer Attacks (AGCA), Multi-agent Intrusion Detection and Protection System (MIDPS), Agent-based Environment for Simulation of DDoS Attacks and Defense (AESAD) and Mobile Agent...
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Switching Regulation in the Control of 5-Phase Permanent Magnet Synchronous Motor Fed by 3×5 Direct Matrix Converter
PublicationMatrix converter is an AC-AC direct power converter comprising of an array of bi- directional switches. It does not require an intermediate DC-link and allows sinusoidal output waveforms with varying amplitudes and frequencies. The configuration of these bi- directional switches decides the number of inputs and outputs...
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Multi Queue Approach for Network Services Implemented for Multi Core CPUs
PublicationMultiple core processors have already became the dominant design for general purpose CPUs. Incarnations of this technology are present in solutions dedicated to such areas like computer graphics, signal processing and also computer networking. Since the key functionality of network core components is fast package servicing, multicore technology, due to multi tasking ability, seems useful to support packet processing. Dedicated...
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Model of control plane of ASON/GMPLS network
PublicationASON (Automatic Switched Optical Network) is a concept of optical network recommended in G.8080/Y.1304 by ITU-T. Control Plane of this network could be based on GMPLS (Generalized Multi-Protocol Label Switching) protocols. This solution, an ASON control plane built on GMPLS protocols is named ASON/GMPLS. In the paper, we decompose the control plane problem and show the main concepts of ASON network. We propose a hierarchical architecture...
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Polyarmonic model of synchronous generator for analysis of autonomous power generation systems
PublicationAbstract: This paper presents the polyharmonic modelling of synchronous generator (SG) in machine variables. The simple geometry and windings physical layout has been used for inductance calculations of a salient-pole SG. The main advantage of this model is the ease of describing an autonomous power generation system (APGS) in terms of its topology and thus providing effective analysis at the static and dynamic states, both for...
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Particle Image Velocimetry Measurements of Airflow in Electrohydrodynamic Device for Dust Particle Collection
PublicationIn this paper the electrohydrodynamic (EHD)device for gas pumping and cleaning is presented. To induce an airflow in this EHD device corona discharge was used. The discharge was generated between the one-sided spike electrodes and the plate electrodes. An asymmetric electric field and generated discharge result in unidirectional gas flow through the EHD device. The current-voltage characteristics were measured and the corona discharge...
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Evaluation Of Single Pole Auto-Reclosing Effectiveness With Nonlinear Secondary Arc Model
PublicationThe paper discusses two evaluation methods of single pole auto-reclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a non-linear secondary arc implementation is presented. The authors indicate, that precise representation of secondary electric arc leads to more...
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Particle Image Velocimetry Measurements of Airflow in Electrohydrodynamic Device for Dust Particle Collection
PublicationIn this paper the pumping effect of air in the electrohydrodynamic (EHD) device for dust particle collection is presented. To induce an airflow in this EHD device corona discharge was used. The discharge was generated between the one-sided spike electrodes and the plate electrodes. The asymmetric electric field and generated discharge resulted in a unidirectional airflow through the EHD device. The current-voltage characteristics...
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Application of wet powder spraying for anode supported solid oxide fuel cell with a perowskite SrTi0.98Nb0.02O3-d anode
PublicationAnode-supported solid oxide fuel cell with SrTi0.98Nb0.02O3–d anode, yttria-stabilized zirconia electrolyte and La(Ni0.6Fe0.4) O3d cathode has been successfully fabricated and evaluated. Process of anode support fabrication has been presented. Wet powder spraying and high temperature sintering method have been studied and applied to deposit the thin electrolyte layer.In order to improve catalytic properties of the anode, it has...
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Implementation of DEIS for reliable fault monitoring and detection in PEMFC single cells and stacks
PublicationDynamic Electrochemical Impedance Spectroscopy (DEIS) was presented as novel method for diagnostic and monitoring of PEMFC stack and single cells operation. Impedance characteristics were obtained simultaneously with current - voltage characteristics for stack and each individual cell. Impedance measurements were performed in galvanodynamic mode. It allowed to compare performance of each cell and identification of faulty cell operation...
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Power Electronic Transformer For Smart Grid Application
PublicationIn this paper the control system of Power Electronic Transformer (PET) for the Smart Grid application is proposed. The structure of PET is based on two Cascaded H-bridge (CHB) converters. The electrical energy is transferred between converters using Dual-Active-Bridges (DAB) and high-frequency transformers. This type of coupling has been used to connect the DC-links of all H-bridges. The proposed control system for PET makes it...
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Asymmetrical Modes in Polyphase Motors and Drives
PublicationThe effect of power supply and/or motor asymmetry on the phase-load distribution and the ripple of electromagnetic torque in a polyphase drive is studied by the method of symmetrical components. It is shown that the presence of asymmetry causes the mapping of all harmonics in the supply voltage into all planes of symmetrical components and eliminates the possibility of independent control of harmonics. The dynamic model of a five-phase...
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Evolutionary Algorithms in MPLS network designing
PublicationMPLS technology become more and more popular especially in core networks giving great flexibility and compatibility with existing Internet protocols. There is a need to optimal design such networks and optimal bandwidth allocation. Linear Programming is not time efficient and does not solve nonlinear problems. Heuristic algorithms are believed to deal with these disadvantages and the most promising of them are Evolutionary Algorithms....
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Low-power device simulator for micro-energy measurement methods testing
PublicationThe paper presents low-power device simulator designed for testing of micro-energy measurement methods. Such kind methods can be used for evaluation of power systems based on Energy Harvesting. The device allows to set the current consumption characteristic over the time, thus making possible playing the role of different types of low-power devices e.g. simulating sensor network node.
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Planning a Cost-Effective Delay-Constrained Passive Optical Network for 5G Fronthaul
PublicationWith the rapid growth in the telecommunications industry moving towards 5G and beyond (5GB) and the emergence of data-hungry and time-sensitive applications, Mobile Network Operators (MNOs) are faced with a considerable challenge to keep up with these new demands. Cloud radio access network (CRAN) has emerged as a cost-effective architecture that improves 5GB performance. The fronthaul segment of the CRAN necessitates a high-capacity...
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Time Synchronization between the eNBs in E-UTRAN under the Asymmetric IP Network
PublicationIn this paper, we present a method for a time synchronization between the two eNodeBs (eNBs) in E-UTRAN (Evolved Universal Terrestrial Radio Access) network. The...
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Remote Monitoring System for Impedance Spectroscopy using Wireless Sensor Network
PublicationThe architecture of a miniaturized impedanceanalyser with wireless communication module for remoteImpedance Spectroscopy (IS) of anticorrosion coatings ondifficult-to-reach objects (e.g. on the steel construction ofthe bridge) is described in this paper. Some practical aspectsof implementation of a Wireless Sensor Network (WSN) arealso discussed. A low scale, middle range, WSN networkcomposed of a Base Station (BS) with a Personal...
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Application of sliding switching functions in backstepping based speed observer of induction machine
PublicationThe paper presents an analysis of the speed observer which is based on the backstepping and sliding mode approach. The speed observer structure is based on the extended mathematical model of an induction machine. The observer structure is based on the measured phase stator currents and transformed to ( αβ ) coordinate system. The stator voltage vector components are treated as known values. Additionally, such an observer structure...
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Cross-Bonding of MV Cable Lines for Energy Losses Decrease
PublicationCurrently, almost all medium voltage cable lines (MV) operate with the return wires earthed at both ends of the cable. Such a way of operation causes that during normal states of operation as well as during disturbances, e.g. short-circuits, in the return wires induce currents whose values mainly depend on the currents flowing in the phase wires. These currents in normal operating states are a source of additional energy losses...
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The Impact of Wind Generation on the Transmission System
PublicationThis article has been published to investigate the im-pact of the wind power on the power system- this is a system dependent issue that requires to perform sys-tem specific impact study. This paper discusses the impact of power flow, short circuit current, power quali-ty, voltage stability and the power system during the connection of a wind farm into transmission system. W referacie omówiono wpływ farm wiatrowych na pracę systemu...
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Performance Analysis of the "Intelligent" Kirchhoff- Law - Johnson-Noise Secure Key Exchange
PublicationThe Kirchhoff-law - Johnson-noise (KLJN) secure key distribution system provides a way of exchanging theoretically secure keys by measuring random voltage and current through the wire connecting two different resistors at Alice’s and Bob’s ends. Recently new advanced protocols for the KLJN method have been proposed with enhanced performance. In this paper, we analyze the KLJN system and compare with the „intelligent” KLJN (iKLJN)...
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Photoelectrochemical properties of BIMEVOX (ME=Cu, Zn, Mn) electrodes in contact with aqueous electrolyte
PublicationLayered oxide Bi4O2O11 and mixed oxides of bismuth, vanadium and a third metal (ME = Cu, Zn, Mn) were synthesized and characterized using XRD, Raman and SEM. The energy band gap (Eg) of samples determined using UV–VIS reflectance spectra equals to 2.46, 2.34, 2.27 and 2.18 eV for Bi4V2O11, BICUVOX (Bi2V1 − xCuxO5.5 − 3x/2), BIZNVOX (Bi2V1 − xZnxO5.5 − 3x/2) and BIMNVOX (Bi2V1 − xMnxO5.5 − x/2) (x = 0.1), respectively. Open circuit...
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Filtering EBG Structures Implemented in Coplanar Waveguide Feedline of Planar Slot Antenna
PublicationA novel compact dual-band slot antenna fed by a coplanar waveguide (CPW) incorporating electromagnetic band gap (EBG) structures has been proposed. At first, a classic wideband slot antenna fed by a CPW, dedicated to work in 2 ÷ 18 GHz band, has been designed. Subsequently, by adding simple EBG filtering structures into a CPW feedline, a dual-band performance ranging from 2.5 to 5.3 GHz and from 13.5 to 16.3 GHz, with the voltage...
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Self-Testing of Analog Parts Terminated by ADCs Based on Multiple Sampling of Time Responses
PublicationA new approach for self-testing of analog parts terminated by analog-to-digital converters in mixed-signal electronic microsystems controlled by microcontrollers is presented. It is based upon a new fault diagnosis method using a transformation of the set of voltage samples of the time response of a tested analog part to a square impulse into localization curves placed in a multidimensional measurement space. The method can be used...
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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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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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Automatic tuning of a resonant circuit in wireless power supply systems for biomedical sensors
PublicationIn this paper, a tuning method of a resonant circuit suited for wireless powering of miniature endoscopic capsules is presented and discussed. The method allows for an automatic tuning of the resonant frequency and matching impedance of a full wave rectifier loading the resonant circuit. Thereby, the receiver tunes so as to obtain the highest power efficiency under given conditions of transmission. A prototype receiver for wireless...
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Practical aspects of testing superconducting electromagnets by the capacitor discharge method taking into account the non-linearity of circuit parameters
PublicationThe article presents selected issues related to the development and testing of the diagnostics systems dedicated for superconducting electromagnets. The systems were constructed to assess the production quality of superconducting electromagnets of the SIS100 synchrotron, a new accelerator being built as part of the Facility of Antiproton and Ion Research (FAIR). One of the systems is used for automatic checking of electrical connection...
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Residual Current Devices: Selection, Operation, and Testing
PublicationIn this book, the idea for residual current protection has been presented. The evolution in construction types of residual current devices, which has taken place over decades, is discussed. Types and functional properties of the contemporary residual current devices are described. The main parameters of these devices, from the point of view of their selection and application, are indicated. Special constructions of the protective...
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Nitrogen-Incorporated Boron-Doped Nanocrystalline Diamond Nanowires for Microplasma Illumination
PublicationThe origin of nitrogen-incorporated boron-doped nanocrystalline diamond (NB-NCD) nanowires as a function of substrate temperature (Ts) in H2/CH4/B2H6/N2 reactant gases is systematically addressed. Because of Ts, there is a drastic modification in the dimensional structure and microstructure and hence in the several properties of the NB-NCD films. The NB-NCD films grown at low Ts (400 °C) contain faceted diamond grains. The morphology...
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A review on analytical models of brushless permanent magnet machines
PublicationThis study provides an in-depth investigation of the use of analytical and numerical methods in analyzing electrical machines. Although numerical models such as the finite-element method (FEM) can handle complex geometries and saturation effects, they have significant computational burdens, are time-consuming, and are inflexible when it comes to changing machine geometries or input values. Analytical models based on magnetic equivalent...
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Network effects—do they matter for digital technologies diffusion?
PublicationPurpose The main research target of this paper is to capture the network effects using the case of mobile cellular telephony, identified in European telecommunication markets, and its determinants enhancing the process of digital technologies diffusion. Design/methodology/approach This research relies on panel and dynamic panel regression analysis. The empirical sample covers 30 European countries, and the period for the analysis...
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DWDM Network Laboratory Solution for Telecommunication Education Engineering
PublicationDevelopment of network architectures in the field of optical telecommunications technologies is an indicator of changes in telecommunication education engineering. Conducting didactic classes requires hardware infrastructure and research in terms of teaching needs. In the paper we present DWDM network laboratory solution for telecommunication education engineering on the basis of the ADVA Optical Networking equipment. We have to...
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Control Strategy of a Five-Phase Induction Machine Supplied by the Current Source Inverter With the Third Harmonic Injection
PublicationIn the five-phase induction machine (IM), it is possible to better use the electromagnetic circuit than in the three-phase IM. This requires the use of an adequate converter system which will be supplied by an induction machine. The electric drive system described, in this article, includes the five-phase induction machine supplied by the current source inverter (CSI). The proposed novelty—not presented previously—is the control...
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Inception and Propagation of Electrical Trees in the Presence of Space Charge in HVAC Extruded Cables
PublicationThis paper presents the space charge impact on the inception and propagation of electrical trees in cross-linked polyethylene (XLPE) insulation via simulations and experimentation. A 3D finite element analysis (FEA)-based modeling is proposed to simulate electrical trees via a needle embedded on the XLPE insulation. The proposed FEA model demonstrates the influence of the space charge magnitude and polarity on the initiation of...
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Information-driven network resilience: Research challenges and perspectives
PublicationInternet designed over 40 years ago was originally focused on host-to-host message delivery in a best-effort manner. However, introduction of new applications over the years have brought about new requirements related with throughput, scalability, mobility, security, connectivity, and availability among others. Additionally, convergence of telecommunications, media, and information technology was responsible for transformation...
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High voltage protective assembly.
PublicationW referacie opisano zestaw zabezpieczeniowy, składający się z bezpiecznika i ogranicznika przepięć, przeznaczony dla napowietrznych słupowych stacji transformatorowych średnich napięć. Zastosowany warystorowy ogranicznik przepięć spełnia jednocześnie rolę wspornika dla bezpiecznika gazowydmuchowego. W referacie przedstawiono budowę, podstawowe parametry, przykłady zastosowania oraz wyniki badań zwarciowych zestawu.
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Transmission protocol simulation framework for the resource-constrained sensor network
PublicationIn this paper the simulation framework for simulation of the sensor network protocol is presented. The framework enables the simultaneous development of the sensor network software and the protocol for the wireless data transmission. The advantage of using the framework is the convergence of the simulation with the real software, because the same software is used in real sensor network nodes and in the simulation framework. The...
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Methods of Network Resource Provisioning for the Future Internet IIP Initiative
PublicationIn this paper, we present specification, design and implementation aspects of a network resource provisioning module introduced for the Polish Initiative of Future Internet called System IIP. In particular, we propose a set of novel LP optimization models of network resource provisioning designed to minimize the network resource consumption, either bandwidth or node’s computational power, as well as to maximize the residual capacity....
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Sensorless Multiscalar Control of Five-Phase Induction Machine with Inverter Output Filter
PublicationThe paper presents a complete solution for speed sensorless control system for five-phase induction motor with voltage inverter, LC filter and nonlinear control of combined fundamental and third harmonic flux distribution. The control principle, also known as multiscalar control, nonlinear control or natural variables control, is based on a use of properly selected scalar variables in control feedback to linearize controlled system....
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Robust identification of quadrocopter model for control purposes
PublicationThe paper addresses a problem of quadrotor unmanned aerial vehicle (so-called X4-flyer or quadrocopter) utility model identification for control design purposes. To that goal the quadrotor model is assumed to be composed of two abstracted subsystems, namely a rigid body (plant) and four motors equipped with blades (actuators). The model of the former is acquired based on a well-established dynamic equations of motion while the...