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Optimization of Electrical and Electronic Equipment (OPTIM), 2010 12th International Conference on

Date 20-22 May 2010

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Displaying Results 1 - 25 of 198
  • Development of hardware redundant embryonic structure for high reliability control applications

    Page(s): 728 - 733
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (897 KB) |  | HTML iconHTML  

    As it is known, the immune system found in biological organisms is robust and able to identify a large scale of diseases, infectious pathogens, or other harmful effects. Built on a huge cell-based structure in a well organized hierarchical mechanism, this system expresses remarkable self-healing, surviving and evolution abilities. The basic idea of the paper is to take inspiration of these mechanisms and associate with principles to engine complex VLSI digital systems for high reliability control applications. For this reason, an embryonic structure was developed and modeled, which expresses similar fault-tolerance and robustness properties like their equivalents from the biological world. Computer simulations prove that these remarkable capabilities would be more advantageous in many applications where robustness and high reliability requirements are imposed. The theoretical approaches and developed models were acquired in hardware redundant embryonic structure, built on a FPGA-based artificial cell network topology. Laboratory experiments show that the implemented embryonic machine is very suitable for a large scale of high security industrial control applications. View full abstract»

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  • Comparison of wavelet families with application to WiMAX traffic forecasting

    Page(s): 932 - 937
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (337 KB) |  | HTML iconHTML  

    This paper deals with a wavelet based forecasting method for WiMAX traffic time series. It is based on an algorithm composed by a few steps. One of these steps is the computation of the Stationary Wavelet Transform, SWT. This transform has two parameters: the mother wavelet which generates the decomposition and the number of decomposition levels. The aim of this paper is to propose a strategy for the selection of the first parameter. Our work is centered on the following wavelet families Daubechies, Coiflet, Symmlet, Biorthogonal and Reverse Biorthogonal. Some simulation results prove the efficiency of the proposed selection method. View full abstract»

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  • The quality of multiple VoIP calls in an encrypted wireless network

    Page(s): 1052 - 1055
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (165 KB) |  | HTML iconHTML  

    We quantified the user-perceived quality for a VoIP application running in an encrypted wireless network and we experimentally determined the maximum number of parallel VoIP calls that can be achieved, at the best quality of the speech signal. We studied the behaviour of the application for four encryption mechanisms and for each of them we measured the bandwidth waste due to encryption. We used the ITU-T PESQ score to objectively assess the quality of the speech signal. In this paper we present the test setup and the tools we used for our experiments, as well as our experimental results and conclusions. View full abstract»

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  • Focusing control under microscopic views based on regional monotones of image focal values

    Page(s): 896 - 902
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (450 KB) |  | HTML iconHTML  

    Generally, clarity of images or focal value (FV) varies in hill-shaped manner with respect to lens motion in a focus region. However, the FV variation in the far-off focused region is usually subjected to disturbances and the image signals may not be informative for focusing control. Therefore, challenges exist if focusing control under microscopic views for a large depth of lens displacement is needed. The challenges are primarily due to lack of a method to differentiate image FVs at far-off focused regions. View full abstract»

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  • Reducing noise in embedded systems by clock signal spectrum spreading

    Page(s): 975 - 980
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (824 KB) |  | HTML iconHTML  

    Clock modulation has the role of reducing electromagnetic interference (EMI) by spreading the spectrum of the clock signal. This method is implemented in the Fujitsu 16 bit and 32 bit microcontrollers. Experiments were conducted on the MB91F362GA microcontroller, with the modulated clock extracted on a special pin and the emitted signals measured with a spectrum analyzer. View full abstract»

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  • Modeling of saturation in salient pole synchronous machines

    Page(s): 258 - 263
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (350 KB) |  | HTML iconHTML  

    The design of high performance motors must take into account not only the steady state but also practically inevitable dynamic state. In such conditions an accurate predetermination of the parameters and constructive solution by modeling and simulation of the dynamic state, becomes a mandatory step. In this aim, in the present paper an enhanced mathematical model of the synchronous machine is briefly presented. We proposed to consider especially the effects of the magnetic saturation, with preservation of the fundamental harmonic of the magnetic field, and saliency. The model assumptions are specified and it is shown that they ensure and improved representation of the main field saturation and saliency. The enhanced model proves to be useful and versatile and is recommended for the analysis of complex dynamical processes when a high accuracy is required. The qualitative and quantitative results show an important number of valuable information in the design stage of the synchronous machine. View full abstract»

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  • Optimal selection of wind turbine for a specific area

    Page(s): 1224 - 1229
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (323 KB) |  | HTML iconHTML  

    In this paper a method for reliability estimation of power systems including wind energy generators is presented. The method is useful to compare different wind turbine generator types and to establish the suitable wind generator type in a given area. The wind generator parameters to be considered for an optimal selection are also presented in details, having in view the improvement of system reliability indices concerning mainly the available generated power. View full abstract»

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  • Capacitive sensors for position acquisition of linear drives with passive vehicles

    Page(s): 673 - 680
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1248 KB) |  | HTML iconHTML  

    Long stator permanent magnet synchronous linear drives with passive, lightweight movers (vehicles) are proposed for material handling systems. For high quality speed and position control of the vehicles, precise and fast position measurement is necessary. These passive vehicles provoke challenges for the position acquisition system as neither energy nor information must be transmitted to the moving parts. The paper analyses the principle of operation of a capacitive sensor and presents two methods of extracting the position information, one uses instantaneous demodulation and the other is based on phase measurement. View full abstract»

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  • Improving and measuring the efficiency of the speed sensorless vector controlled induction motor

    Page(s): 681 - 688
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (519 KB) |  | HTML iconHTML  

    In this paper an accurate loss model-based controller to calculate the optimal air gap flux is proposed. The model includes copper losses, iron losses, harmonic losses, friction and windage losses, and stray losses. These losses are represented as a function of the air gap flux. By using the calculated optimal air gap flux compared with rated flux for speed sensorless indirect vector controlled induction motor, an improvement in motor efficiency and power factor is achieved especially at light load. By adapting the motor voltages and currents signals, load torque meter signal, and position sensor signal the average electrical and mechanical motor powers are calculated in a FPGA. The accuracy of the calculated electrical power is calibrated by using advanced power meter with accuracy equal 0.1% to verify the recommendation of the standard IEEE 112B for measuring the efficiency of the three phase induction motor. The improvement of the efficiency, the power factor and the motor stability under fast load variations by using the proposed optimal flux control method is compared with the rated flux control method experimentally. View full abstract»

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  • Methods for cogging torque reduction of directly driven PM wind generators

    Page(s): 1161 - 1166
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1863 KB) |  | HTML iconHTML  

    This paper deals with several methods for the reduction of cogging torque in case of low speed permanent magnets wind generators. The first analyzed method consists in asymmetrical spacing of the permanent magnets on the rotor outer surface. The second method consists in using close stator slots that determines a nearly isotropic magnetic stator structure. The last investigated method consists in stator skewing. The smallest cogging torque results however were obtained by combining closed stator slots with the other two studied methods. The proposed solutions for cogging torque reduction are analyzed by means of 2D/3D finite element models developed using the professional Flux software package. The numerical results are discussed and compared with experimental measurements. View full abstract»

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  • Electromagnetic pumping of molten salts

    Page(s): 264 - 272
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1107 KB) |  | HTML iconHTML  

    This paper investigates the possibility to control through electromagnetic pumping the molten salts flow in high temperature heat transfer applications. Based on finite element models there were evaluated and compared parameters of multi-phase induction pumps with cylindrical, annular or flat pumping channels and of conduction pumps with ac or quasi-dc electric power supply. View full abstract»

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  • Simple comparison of different PWM strategies for a three-level H-bridge flying capacitor converter

    Page(s): 544 - 550
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (568 KB) |  | HTML iconHTML  

    The paper presents a comparison of phase-shifted and modified level-shifted carrier-based PWM strategies for a three-level H-bridge flying capacitor converter. While the optimal voltage quality of the nearest level switching may be obtained using both of them, natural voltage balancing dynamics is different. Using elementary circuit theory and switched system time domain analysis, it is possible to obtain simple analytical averaged voltage balancing dynamics solutions. Modified level-shifted carrier-based PWM is shown to provide much faster voltage balancing dynamics, especially, for small DC PWM voltage commands and AC PWM modulation indices. The explanation of this fact is obtained by analysis of zero voltage state sequences for different modulation strategies. Relatively fast voltage balancing dynamics rate provided by modified level-shifted carrier-based PWM for zero voltage command makes it possible to implement simple flying capacitors self-precharge procedure at power-up. View full abstract»

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  • Aspects regarding dynamic regimes modelling, simulation and monitoring for reluctance synchronous motors

    Page(s): 273 - 278
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    This paper presents a series of transient regimes specific to the reluctance synchronous motors operation. There are detailed the used mathematical model, having the currents and the speed as state variables, the Matlab-Simulink model obtained on the basis of these equations, the simulations obtained in the case of the asynchronous starting and when some torque and voltage disturbances occur. Finally, there are presented the experimental results, obtained with the help of a stand fitted out with a high speed data acquisition board and the conclusions which have emerged from the simulations and experiments analysis. View full abstract»

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  • Design of a plasma generator based on E power amplifier and impedance matching

    Page(s): 1317 - 1322
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (562 KB) |  | HTML iconHTML  

    The paper presents the design key issues for a plasma generation method. A Class E Power Amplifier is used to generate plasma at 13.56MHz with a variable load implemented with an air coil and a variable capacitor. Class E amplifier represents a mean of high efficiency power amplification. Ideal amplifiers reach 100% efficiency and by proper filtering and tuning even the real circuit efficiency can be only 5% lower. By measuring the input impedance of the matching network the resistance, the voltage and the power of the plasma torch can be estimated. In order to do that, two matching networks were designed; the first one is partially compensated and the second is completely compensated. The problems that can appear at a capacitive tuning in air and Argon atmosphere are also presented. Finally, the steps needed to design the plasma generator with class E power amplifier and air coils are described. View full abstract»

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  • Extended RRT algorithm with dynamic N-dimensional cuboid domains

    Page(s): 851 - 857
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1607 KB) |  | HTML iconHTML  

    The paper presents an approach to path planning problem for manipulators operating in difficult environments with high probability of collisions. The approach improves the Rapidly exploring Random Trees (RRT) algorithm and produces a new approach with better results. It is achieved by expanding the forward and backward tree and reducing dynamically the sampling area of the free-configuration space (C-Space) by introducing a N-Dimensional cuboid regions. The place of this area could be dynamically or statically defined. The results show that this modification provides a very reasonable solution to the path planning problem applicable also to any kind of manipulators. View full abstract»

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  • Design, control and monitoring of a synchronous linear motor servo drive system based on distributed controllers

    Page(s): 696 - 703
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (523 KB) |  | HTML iconHTML  

    Over the last years the usage of linear motors in many industrial fields increased. A design of a modular servo drive system based on permanent magnet synchronous linear motors is shown here. The control method implemented and the means by which the system can be monitored are presented. The proposed system topology differentiates itself from other topologies due to its scalability potential, so that the system can expand as much as the application requires it. View full abstract»

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  • Noncoherent demodulation of continuous phase modulated signals using Extended Kalman Filtering

    Page(s): 724 - 727
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (279 KB) |  | HTML iconHTML  

    The paper addresses the problem of demodulating Continuous Phase Modulation (CPM) signals embedded in Gaussian noise. The paper introduces a description of CPM signals by a state-space model. Based on this model, a noncoherent demodulation method of CPM signals, that uses an Extended Kalman Filter (EKF), was developed. The performances of the demodulation method were tested on two types of CPM modulated signals, embedded in noise: Minimum Shift Keying (MSK) and Gaussian Minimum Shift Keying (GMSK). The results, obtained from simulations performed in MATLAB, leaded to the conclusion that, for moderately low Signal to Noise Ratios (SNR), the EKF algorithm provides satisfactorily even good results in noncoherent demodulation of CPM signals. View full abstract»

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  • Three-level ASNPC converter implemented with an analogue command

    Page(s): 646 - 651
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    The three-level Active Stacked Neutral Point Clamped converter is presented. The main advantage of this structure is the half reduction of the average switching frequency of all devices. This paper is focused on the analogue command of the 3L-ASNPC structure. The advantages of this modulation method are its simplicity and reduce cost. Experimental results are shown to validate the efficiency of this command method. View full abstract»

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  • GALS-SA: Synchronous-asynchronous configurable platform

    Page(s): 963 - 970
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (347 KB) |  | HTML iconHTML  

    The paper presents a new class of hybrid circuits named GALS-SA (Globally Asynchronous Locally Synchronous - Structured ASIC) that incorporates the advantages of GALS (Globally Asynchronous Locally Synchronous) architecture together with the ones of structured ASIC platforms. Specialized modules are developed to implement asynchronous communication channel between synchronous modules. Dedicated test modules are added to the new hybrid structure to ensure the newly added resources can be tested. The structure is designed to ensure that already existent synchronous implementation flow can be applied with very few specific, nonstandard steps to implement a fully synchronous design as a GALS design. View full abstract»

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  • Evaluation of the performances of efficient transformers in distribution networks by fuzzy techniques

    Page(s): 1281 - 1284
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB) |  | HTML iconHTML  

    The replacement of the old transformers with efficient transformers provide an excellent opportunity to conserve energy right from the distribution installations and to recover the cost of equipment rendered obsolete by deployment of the Smart Grid System. The size and complexity of distribution networks make it impossible to carry out an exhaustive analysis and consequently, the assessment of solutions for various optimization problems. One of the most important such problems is to evaluate energy saving solutions for these networks. The paper proposes using fuzzy techniques to overcome this difficulty. A study case is presented for an urban distribution network, by using the fuzzy techniques. View full abstract»

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  • The magnetic noise of inverter-fed three-phase induction motors with squirrel cage rotors

    Page(s): 279 - 284
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1001 KB) |  | HTML iconHTML  

    The paper analyzes the magnetic noise in inverted-fed single speed three-phase induction motors with squirrel cage rotor. The motors are totally enclosed and externally cooled. Investigation includes motors with the rated speeds of 3000, 1500, 1000 and 750 r/min. The investigated motors were placed in the semi-anechoic chamber in order to determine the noise-to-frequency characteristics (spectrograms). This paper is based on the results and conclusions obtained after analyzing these spectrograms. The importance of the pressure, which is applied for the stacking of the stator laminations to the level of the magnetic noise, is presented as well. View full abstract»

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  • Design and analysis of a coreless flyback converter with a planar printed-circuit-board transformer

    Page(s): 557 - 563
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (631 KB)  

    In this paper the development of a 1W DC/DC converter is presented. It is based on a flyback converter for simple applications. The transformer is designed in a form as a spiral coil on a PCB. The special feature of the converter is that the flyback converter is laid out without a core. The area (diameter) of a spiral coil should be bigger as a coil with a core because the air is not a good energy store. The advantage of a coreless transformer is the PCB-Design. The paper describes the theory of the flyback converter and shows a way of the implementation of the coreless planar transformer. An analysis shows some results by different geometry and frequency of the planar transformer. View full abstract»

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  • A calibration laboratory for Rogowski Coil used in energy systems and power electronics

    Page(s): 913 - 919
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (739 KB) |  | HTML iconHTML  

    The use of the well known Rogowski Coil (RC) sensor gained a wide spread due to its many applications in testing laboratories, industrial measuring instruments, power electronics and unconventional measuring systems used in energy transport networks. These sensors have been rendered valuable due both to the special dynamic properties, lack of saturation etc. and to the important progresses made in the acquisition and processing systems of the experimental data. The drawing up of the first IEC standard referring to high current measurement (IEC 62475) where the metrological properties of the shunts and RC are stated both in permanent and in transient duty are proofs of the progresses in this domain. After a short review of the main RC types, their operating duties, specific testing installations and measurement uncertainty are analysed. At the same time as the accreditation of the High Current Calibration Laboratory granted by DKD (German Calibration Service) in 2008, there are placed at disposal the own standards with traceability to the international standards and certain RC specific tests described in this paper could be added to the tests already evaluated within the usual frame of accreditation extension. View full abstract»

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  • DFIG turbine representation for small signal voltage control studies

    Page(s): 31 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (452 KB) |  | HTML iconHTML  

    This paper addresses the representation of a wind power plant, based on wound rotor asynchronous generators, with a centralized voltage controller, by an equivalent transfer function, valid for small signal voltage control studies. This representation allows to investigate the influence of the centralized plant control gain and short circuit ratio on the system stability, for instance, by analyzing the zero-pole placement. Larger percentages of wind power penetration translate to more demanding requirements coming from the grid codes, for example voltage support at the point of connection has been introduced recently by several grid codes from around the world, making important to analyze this control when applied to wind power plants. The performance of the equivalent transfer function has been evaluated and compared using an equivalent grid with different short circuit ratios and active power injection levels, the cases have been simulated with PSCAD/EMTDC program. Results show that this equivalence can be used for short circuit ratios between 5 and 25 for obtaining an accurate representation of the system voltage dynamics. View full abstract»

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  • Switched reluctance motor analytical models, comparative analysis

    Page(s): 285 - 290
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (702 KB) |  | HTML iconHTML  

    Two categories of analytical models developed for switched reluctance motor (SRM) are discussed in the paper. The models are based on motor geometry data and respectively on finite element method (FEM) analysis results. For an existing and tested sample SRM the flux linkage and the torque characteristics were calculated via all considered models and the results were compared with the FEM analysis based calculated characteristics. Finally the merits and the weak points of each model were evinced. View full abstract»

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