Variable-Speed, Robust Synchronous Reluctance Machine Drive Systems
Wang, Dong
The synchronous reluctance machine drive is getting more and more interests from the industrial side, since it can provide higher system energy efficiency than traditional inverter-fed induction machine drive systems with similar production cost. It is considered as a good candidate for super...... premium efficiency machine and commercial products are available in the market. The research work in this dissertation aims at developing a simple, compact and robust synchronous reluctance machine drive system that can provide satisfactory performance with optimized system energy efficiency at various...... working conditions. Field oriented control assisted with various position estimation algorithms is in-vestigated. Position sensing via machine flux linkage is implemented with the assistance of a widely used flux observer. Experiments show that it may not always work properly and system oscillation...
Variable-Speed, Robust Synchronous Reluctance Machine Drive Systems
Wang, Dong
algorithm, the proposed machine inductance in-dependent position estimation algorithm shows better dynamic response against the step load changes but requires more accurate signal sampling in steady state. Therefore, the flux linkage based position estimation algorithm with adaptive PI controllers......The synchronous reluctance machine drive is getting more and more interests from the industrial side, since it can provide higher system energy efficiency than traditional inverter-fed induction machine drive systems with similar production cost. It is considered as a good candidate for super...... inductance independency. High frequency signal injection based on duty cycle shifting is introduced, which can achieve signal injection without sacrificing the maximum allowable fundamental voltage for torque production, so that the machine induct-ance independent position estimation algorithm can...
Wu, Qian; Lu, Kaiyuan; Rasmussen, Peter Omand
2016-01-01
This paper introduces a new application of moulding technology to the installation of ferrite magnet material into the rotor flux barriers of Ferrite Magnet Assisted Synchronous Reluctance Machine (FASynRM). The feasibility of this application with respect to manufacturing process and motor...... performance has been demonstrated. In comparison to the conventional ferrite magnet installation approach, moulding technology has obvious advantages of improved mechanical strength of the multi-flux-barrier rotor structure, simplified installation process, reduced processing cost and in the same time...
Liu Xiping
2017-06-01
Full Text Available This paper proposes a permanent magnet (PM-assisted synchronous reluctance machine (PMASynRM using ferrite magnets with the same power density as rareearth PM synchronous motors employed in Toyota Prius 2010. A suitable rotor structure for high torque density and high power density is discussed with respect to the demagnetization of ferrite magnets, mechanical strength and torque ripple. Some electromagnetic characteristics including torque, output power, loss and efficiency are calculated by 2-D finite element analysis (FEA. The analysis results show that a high power density and high efficiency of PMASynRM are obtained by using ferrite magnets.
The rediscovery of synchronous reluctance and ferrite permanent magnet motors tutorial course notes
Pellegrino, Gianmario; Bianchi, Nicola; Soong, Wen; Cupertino, Francesco
2016-01-01
This book offers an essential compendium on the analysis and design of synchronous motors for variable-speed applications. Focusing on synchronous reluctance and ferrite permanent-magnet (PM) synchronous reluctance machines, it provides a broad perspective on three-phase machines for variable speed applications, a field currently dominated by asynchronous machines and rare-earth PM synchronous machines. It also describes synchronous reluctance machines and PM machines without rare-earth materials, comparing them to state-of-the-art solutions. The book provides readers with extensive information on and finite element models of PM synchronous machines, including all relevant equations and with an emphasis on synchronous-reluctance and PM-assisted synchronous-reluctance machines. It covers ferrite-assisted machines, modeled as a subcase of PM-assistance, fractional slot combinations solutions, and a quantitative, normalized comparison of torque capability with benchmark PM machines. The book discusses a wealth o...
Study of the Synchronous Reluctance Motor Design
Dirba J.
2016-08-01
Full Text Available The paper focuses on studying the external-rotor synchronous reluctance motor. The analysis is performed to estimate the influence of the number of stator slots and non-magnetic areas in the rotor (i.e., flux barriers on the electromagnetic torque and torque ripple of the studied motor. It is concluded that the increase in the number of stator slots Z = 6 to Z = 18 causes an approximately twofold decrease in the ripple factor, but torque increases by 5 %. Electromagnetic torque will be increased approximately by 24 %, if non-magnetic flux barriers are created in the rotor of the studied synchronous reluctance motor.
Pitic, Cristian Ilie; Tutelea, Lucian; Boldea, Ion;
2004-01-01
Permanent Magnet-assisted Reluctance Synchronous Machines (PM-RSM) are well known for their lower initial costs and losses in a very wide constant power-speed characteristic. Therefore they are very suitable for hybrid or electrical vehicles. In this application a very good torque control is need...
Pitic, Cristian Ilie; Tutelea, Lucian; Boldea, Ion
2004-01-01
Permanent Magnet-assisted Reluctance Synchronous Machines (PM-RSM) are well known for their lower initial costs and losses in a very wide constant power-speed characteristic. Therefore they are very suitable for hybrid or electrical vehicles. In this application a very good torque control is needed...
Reluctance Machine for a Hollow Cylinder Flywheel
Magnus Hedlund
2017-03-01
Full Text Available A hollow cylinder flywheel rotor with a novel outer rotor switched reluctance machine (SRM mounted on the interior rim is presented, with measurements, numerical analysis and analytical models. Practical experiences from the construction process are also discussed. The flywheel rotor does not have a shaft and spokes and is predicted to store 181 Wh / kg at ultimate tensile strength (UTS according to simulations. The novel SRM is an axial flux machine, chosen due to its robustness and tolerance for high strain. The computed maximum tip speed of the motor at UTS is 1050 m / s . A small-scale proof-of-concept electric machine prototype has been constructed, and the machine inductance has been estimated from measurements of voltage and current and compared against results from analytical models and finite element analysis (FEA. The prototype measurements were used to simulate operation during maximal speed for a comparison towards other high-speed electric machines, in terms of tip speed and power. The mechanical design of the flywheel was performed with an analytical formulation assuming planar stress in concentric shells of orthotropic (unidirectionally circumferentially wound carbon composites. The analytical approach was verified with 3D FEA in terms of stress and strain.
Asynchronized synchronous machines
Botvinnik, M M
1964-01-01
Asynchronized Synchronous Machines focuses on the theoretical research on asynchronized synchronous (AS) machines, which are "hybrids of synchronous and induction machines that can operate with slip. Topics covered in this book include the initial equations; vector diagram of an AS machine; regulation in cases of deviation from the law of full compensation; parameters of the excitation system; and schematic diagram of an excitation regulator. The possible applications of AS machines and its calculations in certain cases are also discussed. This publication is beneficial for students and indiv
Fault tolerant operation of switched reluctance machine
Wang, Wei
The energy crisis and environmental challenges have driven industry towards more energy efficient solutions. With nearly 60% of electricity consumed by various electric machines in industry sector, advancement in the efficiency of the electric drive system is of vital importance. Adjustable speed drive system (ASDS) provides excellent speed regulation and dynamic performance as well as dramatically improved system efficiency compared with conventional motors without electronics drives. Industry has witnessed tremendous grow in ASDS applications not only as a driving force but also as an electric auxiliary system for replacing bulky and low efficiency auxiliary hydraulic and mechanical systems. With the vast penetration of ASDS, its fault tolerant operation capability is more widely recognized as an important feature of drive performance especially for aerospace, automotive applications and other industrial drive applications demanding high reliability. The Switched Reluctance Machine (SRM), a low cost, highly reliable electric machine with fault tolerant operation capability, has drawn substantial attention in the past three decades. Nevertheless, SRM is not free of fault. Certain faults such as converter faults, sensor faults, winding shorts, eccentricity and position sensor faults are commonly shared among all ASDS. In this dissertation, a thorough understanding of various faults and their influence on transient and steady state performance of SRM is developed via simulation and experimental study, providing necessary knowledge for fault detection and post fault management. Lumped parameter models are established for fast real time simulation and drive control. Based on the behavior of the faults, a fault detection scheme is developed for the purpose of fast and reliable fault diagnosis. In order to improve the SRM power and torque capacity under faults, the maximum torque per ampere excitation are conceptualized and validated through theoretical analysis and
Analysis of synchronous machines
Lipo, TA
2012-01-01
Analysis of Synchronous Machines, Second Edition is a thoroughly modern treatment of an old subject. Courses generally teach about synchronous machines by introducing the steady-state per phase equivalent circuit without a clear, thorough presentation of the source of this circuit representation, which is a crucial aspect. Taking a different approach, this book provides a deeper understanding of complex electromechanical drives. Focusing on the terminal rather than on the internal characteristics of machines, the book begins with the general concept of winding functions, describing the placeme
朱熀秋; 曹莉; 刁小燕; 李天博; 邹花蕾
2012-01-01
The principle of the bearingless synchronous reluctance motor (BSRM) is expatiated and the mathematics model is established. Then the least squares support vector machines (LS-SVM) system method is applied to decoupling control of the BSRM, which decouples the original system into 3 relatively independent SISO pseudo-linear subsystems. At the same time, the closed loop linear controllers are designed based on the linear system theory. The simulation system is constructed with Matlab/Simulink software. The simulation results show that this kind of control strategy can realize dynamic decoupling among electromagnetic torque and radial suspension forces of the BSRM, and the control system has excellent dynamic and static performance.%在阐述了无轴承同步磁阻电机(BSRM)工作原理的基础上,建立其数学模型,采用最小二乘支持向量机(LS-SVM)逆系统方法对其进行解耦控制,将原系统解耦成3个相对独立的伪线性子系统,并应用线性系统理论设计了闭环控制器.最后采用Matlab/Simulink构建仿真系统.仿真结果表明:此解耦控制策略能够实现无轴承同步磁阻电机电磁转矩和径向悬浮力之间的动态解耦,且系统具有良好的动、静态特性.
Double U-Core Switched Reluctance Machine
2016-01-01
The present invention relates to an electrical machine stator comprising a plurality of stator segments (131,132,133), each segment comprises a first U-core and a second U-core wound with a winding, where the winding being arranged with at least one coil turn, each coil turn comprises a first axial......(s), wherein the first U-core and the second U-core are located adjacent to each other, whereby the winding spans the first and second U-cores. The invention also relates to a SRM machine with a stator mentioned above and a rotor....
Large power analysis of switched reluctance machine system for coal mine
CHEN Hao; PAVLITOV Constantin
2009-01-01
The conventional structures in the Switched Reluctance machines are introduced, such as three-phase 12/8 structure Switched Reluctance machine, three-phase 6/4 structure Switched Reluctance machine, four-phase 16/12 structure Switched Reluctance machine, and four-phase 8/6 structure Switched Reluctance machine. Three-phase 12/8 structure Switched Reluctance machine is the best choice for the large power Switched Reluctance machine system in coal mines. The asymmetric bridge power converter main circuit and the bifilar winding power converter main circuit are also introduced. Three-phase asymmetric bridge power converter main circuit is the best choice for the large power Switched Reluctance machine system in coal mines. The magnetic paths of the designed large power motor are given with one phase excitation and double phases excitation. The phase current waveforms are also given.
Abbasian Mohammadali
2017-03-01
Full Text Available Double Stator Switched Reluctance Machine (DSSRM is a novel switched reluctance machine with limited information about its heat distribution and dissipation. This paper presents a two dimensional (2-D thermal analysis of Double Stator Switched Reluctance Machine (DSSRM to observe actual heat distribution in the parts of the machine, using Finite Element Method (FEM. Two topologies for the rotor of DSSRM are considered, Non-Squirrel Cage Double Stator Switched Reluctance Machine (NSC-DSSRM and Squirrel Cage Double Stator Switched Reluctance Machine (SC-DSSRM. The heat distribution of these two topologies is analyzed, using Computational Fluid Dynamics (CFD. Finally the results are presented and compared.
Switched reluctance machines control with a minimized sampling frequency
Rain, Xavier; Hilairet, Mickaël; Arias Pujol, Antoni
2014-01-01
This paper is focused on reducing the Switched Reluctance Machines (SRMs) control sampling frequency in order to save processor real time resources, while keeping the stability and also the performance, in terms of average torque and torque ripple. Reducing the CPU cost either by implementing the control algorithm in a less performing CPU or more importantly reducing the percentage of the CPU demand is an attractive goal, especially for the electrical vehicle industry from where the SRM used ...
Yao, Li
2006-01-01
This thesis concerns the modified and improved, time-stepping, dynamic reluctance mesh (DRM) modelling technique for machines and its application to multiple machine systems with their control algorithms. Improvements are suggested which enable the stable solution of the resulting complex non-linear equations. The concept of finite element (FE) derived, overlap-curves has been introduced to facilitate the evaluation of the air-gap reluctances linking the teeth on the rotor to those on the sta...
Metamodels for Optimum Design of Outer-Rotor Synchronous Reluctance Motor
Lavrinovicha Ludmila
2014-05-01
Full Text Available A new design of synchronous reluctance motor with segment-shaped outer rotor is presented and investigated in this paper. In order to obtain correct recommendations for optimal design of the studied synchronous reluctance motor, analytical relations of motor electromagnetic parameters and geometrical dimensions (also known as metamodels have been synthesized. Electromagnetic parameters, which have been used for metamodels synthesis, are obtained by means of magnetostatic field numerical calculations with finite element method using software QuickField.
Air-Gap Convection in a Switched Reluctance Machine
Romanazzi, Pietro
2015-01-01
Switched reluctance machines (SRMs) have recently become popular in the automotive market as they are a good alternative to the permanent magnet machines commonly employed for an electric powertrain. Lumped parameter thermal networks are usually used for thermal analysis of motors due to their low computational cost and relatively accurate results. A critical aspect to be modelled is the rotor-stator air-gap heat transfer, and this is particularly challenging in an SRM due to the salient pole geometry. This work presents firstly a review of the literature including the most relevant correlations for this geometry, and secondly, numerical CFD simulations of air-gap heat transfer for a typical configuration. A new correlation has been derived: $\\mathbf{Nu=0.181\\ Ta_m^{0.207}}$
Brosch, Peter F. [Hochschule Hannover (Germany). Fakultaet I
2012-06-11
Although permanent magnet synchronous motors increase the efficiency, but these motors make use of expensive neodymium-iron-boron magnets. On the other hand, the rotor of a reluctance motor requires neither an excitation winding nor permanent magnets. Moreover, the lack of rotor losses increase the efficiency.
Analysis of a polyphase synchronous reluctance motor with two identical stator windings
Obe, E.S. [Laboratory of Power Devices, Department of Electrical Engineering, University of Nigeria, Nsukka 410001, Enugu State (Nigeria); Senjyu, T. [Department of Electrical and Electronics Engineering, University of the Ryukyus, Nishihara, Nakagami, Okinawa 903-0213 (Japan)
2006-04-15
This paper presents the performance analysis of a cageless two-stator-winding reluctance motor which is capable of developing reluctance torque at good power factors in the absence of inverter control. The machine stator has two separate identical polyphase windings whose pole numbers are the same as that of the cageless rotor. The machine performance is investigated using the traditional circle diagrams, and the d-q rotor reference frame equations derived in space-vector form by applying the concept of winding functions. Core loss and saturation are accounted for in the developed dynamic model. It is shown that if one winding is connected directly to the supply and the other fed with a balanced capacitor, the developed torque is superior to a brushless doubly-fed reluctance machine (BDFRM) of similar size. Other motor characteristics, its line-start behaviour and torque ripples are also presented and discussed. Experimental results corroborate the simulations. (author)
A Novel Linear Switched Reluctance Machine: Analysis and Experimental Verification
N. C. Lenin
2010-01-01
Full Text Available The important problems to be solved in Linear Switched Reluctance Machines (LSRMs are: (1 to design the shape and size of poles in stator and translator cores; (2 to optimize their geometrical configuration. A novel stator geometry for LSRMs that improved the force profile was presented in this study. In the new geometry, pole shoes were affixed on the stator poles. Static and dynamic characteristics for the proposed structure had been highlighted using Two Dimensional (2-D Finite Element Analyses (FEA. Motor performance for variable load conditions was discussed. The finite element analyses and the experimental results of this study proved that, LSRMs were one of the strong candidates for linear propulsion drives. Problem statement: To mitigate the force ripple without any loss in average force and force density. Approach: Design modifications in the magnetic structures. Results: 2-D finite element analysis was used to predict the performance of the studied structures. Conclusion/Recommendations: The proposed structure not only reduces the force ripple, also reduced the volume and mass. The future study is to make an attempt on vibration, thermal and stress analyses.
A New Approach on the Design and Optimization of Brushless Doubly-Fed Reluctance Machines
Staudt, Tiago; Wurtz, Frédéric; Gerbaud, Laurent; Batistela, Nelson Jhoe; Kuo-Peng, Patrick
2014-01-01
International audience; The Brushless Doubly-Fed Reluctance Machine (BDFRM) is being considered as a viable generator alternative to be used in wind turbines. A literature review shows that there is still a lack of researches to define a design procedure to make this machine widely used in such application. This paper aims to address this issue by considering a new BDFRM design method using a reluctance network approach and the concepts of sizing and optimization models. It also presents a ca...
Design of Low-Torque-Ripple Synchronous Reluctance Motor with External Rotor
Lavrinovicha L.
2017-02-01
Full Text Available The paper presents new designs for synchronous reluctance motors that have external rotor (segment-shaped rotor, rotor with additional non-magnetic space to the quadrature axis of the rotor, and rotor with several flux barriers. Impact of the external rotor configuration on the electromagnetic torque and torque ripple is analysed. Electromagnetic torque ripple factor is calculated for each studied motor using the results of magnetic field numerical calculations.
Online MTPA Control Approach for Synchronous Reluctance Motor Drives Based on Emotional Controller
Daryabeigi, Ehsan; Zarchi, Hossein Abootorabi; Markadeh, G. R. Arab
2015-01-01
In this paper, speed and torque control modes (SCM and TCM) of synchronous reluctance motor (SynRM) drives are proposed based on emotional controllers and space vector modulation under an automatic search of the maximum-torque-per-ampere (MTPA) strategy. Furthermore, in order to achieve an MTPA...... variations and external disturbances in both TCM and SCM. In addition, the proposed MTPA strategy shows a reliable and fast response to operating point change....
Simple Design Approach for Low Torque Ripple and High Output Torque Synchronous Reluctance Motors
Mohamed Nabil Fathy Ibrahim
2016-11-01
Full Text Available The rotor design of Synchronous Reluctance Motors (SynRMs has a large effect on their efficiency, torque density and torque ripple. In order to achieve a good compromise between these three goals, an optimized rotor geometry is necessary. A finite element method (FEM is a good tool for the optimization. However, the computation time is an obstacle as there are many geometrical parameters to be optimized. The flux-barrier widths and angles are the two most crucial parameters for the SynRM output torque and torque ripple. This paper proposes an easy-to-use set of parametrized equations to select appropriate values for these two rotor parameters. With these equations, the reader can design a SynRM of distributed windings with a low torque ripple and with a better average torque. The methodology is valid for a wide range of SynRMs. To check the validity of the proposed equations, the sensitivity analysis for the variation of these two parameters on the SynRM torque and torque ripple is carried out. In addition, the analysis in this paper gives insight into the behavior of the machine as a function of these two parameters. Furthermore, the torque and torque ripple of SynRMs having a rotor with three, four and five flux-barriers are compared with three literature approaches. The comparison shows that the proposed equations are effective in choosing the flux-barrier angles and widths for low torque ripple and better average torque. Experimental results have been obtained to confirm the FEM results and to validate the methodology for choosing the rotor parameters.
Shouliang Han; Shumei Cui; Liwei Song; Ching Chuen Chan
2014-01-01
The double-rotor machine is a kind of multiple input and output electromechanical energy transducer with two electrical ports and two mechanical ports, which is an ideal transmission system for hybrid electric vehicles and has a series of advantages such as integration of power and energy, high efficiency and compaction. In this paper, a switched reluctance double-rotor machine (SRDRM) is proposed for hybrid electric vehicles, while no conductor or PM in the middle rotor. This machine not onl...
Improvements of Power Factor and Torque of a Synchronous Reluctance Motor with a Slit Rotor
Nashiki, Masayuki; Inoue, Yoshimitu; Kawai, Youichi; Yokochi, Takanori; Satake, Akiyoshi; Okuma, Shigeru
Power factor and torque of synchronous reluctance motors with a slit rotor are studied. In there stators, divided teeth made of powder magnetic core are adopted and windings are improved to get high space factor of stator windings and to shorten coil ends. In there rotors, stainless sheets are inserted among soft magnetic metal sheets with adhesive to strengthen the rotors and rotor structure is improved to enlarge the saliency ratio (Ld/Lq). As the result, the power factor 0.78 and 1.6 times torque at same motor size are attained.
Flux observer algorithms for direct torque control of brushless doubly-fed reluctance machines
Chaal, Hamza; Jovanovic, Milutin
2009-01-01
Direct Torque Control (DTC) has been extensively researched and applied to most AC machines during the last two decades. Its first application to the Brushless Doubly-Fed Reluctance Machine (BDFRM), a promising cost-effective candidate for drive and generator systems with limited variable speed ranges (such as large pumps or wind turbines), has only been reported a few years ago. However, the original DTC scheme has experienced flux estimation problems and compromised performance under the ma...
A Sensor-less Method for Online Thermal Monitoring of Switched Reluctance Machine
Wang, Chao; Liu, Hui; Liu, Xiao
2015-01-01
Stator winding is one of the most vulnerable parts in Switched Reluctance Machine (SRM), especially under thermal stresses during frequently changing operation circumstances and susceptible heat dissipation conditions. Thus real-time online thermal monitoring of the stator winding is of great......, neither machine parameters nor thermal impedance parameters are required in the scheme. Simulation results under various operating conditions confirm the proposed sensor-less online thermal monitoring approach....
2003-01-01
A translation system, applicable in trains, elevators, aircraft launchers, rail guns, conveyors, door openers, machine tools and servo drives, includes a first linear switch reluctance machine (“LSRM”) having a stator and a translator each configured, positioned and proportioned for electromagentic engagement with the other. The system further includes an assembly for selectable application of at least one phase of a multiphasic DC excitation to the LSRM to produce a longitudinal or propulsiv...
Multon, B.
1994-05-15
This work deals with the optimization of double salience variable reluctance motors with electronic switching. It includes the control laws, the electromagnetic structure and the direct and indirect self-driving sensors. The first chapter presents the state-of-the-art of double salience reluctance machines, their characteristics, their inverters and the evolutions of their electromagnetic structure. Chapters 2 and 3 treat of the optimization of power supplies and of the electromagnetic structure, respectively. Finally, the last chapter treats of original solutions of position measurement for the self-control, one using a variable reluctance sensor, and the other using an indirect sensor. The impact of the motor characteristics on the power supply has been analyzed with the optimization of the control laws in permanent regime and low torque undulation regime. The influence of the motor structure geometry on the electromagnetic characteristics has been studied using analytic methods coupled with punctual finite-element calculations. Using a particular example, a self-oscillating power supply mode has been implemented in order to reduce the losses and the electromagnetic pollution. (J.S.)
Online Dynamic Parameter Estimation of Synchronous Machines
West, Michael R.
Traditionally, synchronous machine parameters are determined through an offline characterization procedure. The IEEE 115 standard suggests a variety of mechanical and electrical tests to capture the fundamental characteristics and behaviors of a given machine. These characteristics and behaviors can be used to develop and understand machine models that accurately reflect the machine's performance. To perform such tests, the machine is required to be removed from service. Characterizing a machine offline can result in economic losses due to down time, labor expenses, etc. Such losses may be mitigated by implementing online characterization procedures. Historically, different approaches have been taken to develop methods of calculating a machine's electrical characteristics, without removing the machine from service. Using a machine's input and response data combined with a numerical algorithm, a machine's characteristics can be determined. This thesis explores such characterization methods and strives to compare the IEEE 115 standard for offline characterization with the least squares approximation iterative approach implemented on a 20 h.p. synchronous machine. This least squares estimation method of online parameter estimation shows encouraging results for steady-state parameters, in comparison with steady-state parameters obtained through the IEEE 115 standard.
Sensorless Control of Permanent Magnet Synchronous Machines
Matzen, Torben N.
to appear. Sensorless control implies control of the machine without using a direct measurement of the rotor position. Instead, more information is extracted from the existing controller feedback signals - often the machine currents - and this information is used together with accurate system knowledge...... machine is also used for servo applications where higher dynamics is required, e.g. in industrial automation. The energy efficiency is essential for battery powered electric vehicles where the electric storage capacity is limited by cost, mass and volume. The control system necessary to operate...... the synchronous machine requires knowledge of the rotor shaft position due to the synchronous and undamped nature of the machine. The rotor position may be measured using a mechanical sensor, but the sensor reduces reliability and adds cost to the system and for this reason sensorless control methods started...
Torque vector control using neural network controller for synchronous reluctance motor
Feng, X. [Teco-Westinghouse Motor Co, R and D Center, Round Rock, TX (United States); Belmans, R.; Hameyer, K. [Katholieke Universiteit Leuven, Dic. ELEN, Dept. ESAT, Leuven-Heverlee (Belgium)
2000-08-01
This paper presents the torque vector control technique using a neural network controller for a synchronous reluctance motor. As the artificial neural network controller has the advantages of faster execution speed, harmonic ripple immunity and fault tolerance compared to a DSP-based controller, different multi-layer neural network controllers are designed and trained to produce a correct target vector when presented with the corresponding input vector. The trained result and calculated flops show that although the designed three layer controller with tansig, purelin and hard limit functions has more processing layers, the neuron number of each layer is less than that of other kinds of neural network controller, the requiring less flops and yielding faster execution and response. (orig.)
Ivanov, A. S.; Kalanchin, I. Yu; Pugacheva, E. E.
2017-09-01
One of the first electric motors, based on the use of electromagnets, was a reluctance motor in the XIX century. Due to the complexities in the implementation of control system the development of switched reluctance electric machines was repeatedly initiated only in 1960 thanks to the development of computers and power electronic devices. The main feature of these machines is the capacity to work both in engine mode and in generator mode. Thanks to a simple and reliable design in which there is no winding of the rotor, commutator, permanent magnets, a reactive gate-inductor electric drive operating in the engine mode is actively being introduced into various areas such as car industry, production of household appliances, wind power engineering, as well as responsible production processes in the oil and mining industries. However, the existing shortcomings of switched reluctance electric machines, such as nonlinear pulsations of electromagnetic moment, the presence of three or four phase supply system and sensor of rotor position prevent wide distribution of this kind of electric machines.
Milutin G. Jovanović
2006-12-01
Full Text Available The brushless doubly-fed machine (BDFM allows the use of a partially rated inverter and represents an attractive cost-effective candidate for variable speed applications with limited speed ranges. In its induction machine form (BDFIM, the BDFM has significant rotor losses and poor efficiency due to the cage rotor design which makes the machine dynamic models heavily parameter dependent and the resulting controller configuration complicated and difficult to implement. A reluctance version of the BDFM, the brushless doubly-fed reluctance machine (BDFRM, ideally has no rotor losses, and therefore offers the prospect for higher efficiency and simpler control compared to the BDFIM. A detailed study of this interesting and emerging machine is very important to gain a thorough understanding of its unusual operation, control aspects and compromises between optimal performance and the size of the inverter and the machine. This paper will attempt to address these issues specifically concentrating on developing conditions for various control properties of the machine such as maximum power factor, maximum torque per inverter ampere and minimum copper losses, as well as analysing the associated trade-offs.
Shouliang Han
2014-10-01
Full Text Available The double-rotor machine is a kind of multiple input and output electromechanical energy transducer with two electrical ports and two mechanical ports, which is an ideal transmission system for hybrid electric vehicles and has a series of advantages such as integration of power and energy, high efficiency and compaction. In this paper, a switched reluctance double-rotor machine (SRDRM is proposed for hybrid electric vehicles, while no conductor or PM in the middle rotor. This machine not only inherits the merits of switched reluctance machine, such as simple salient rotor structure, high reliability and wide speed range, but also can avoid the outer rotor’s cooling problem effectively. By using an equivalent magnetic circuit model, the function of middle rotor yoke is analyzed. Electromagnetic analyses of the SRDRM are performed with analytical calculations and 2-D finite element methods, including the effects of main parameters on performance. Finally, a 4.4 kW prototype machine is designed and manufactured, and the tests are performed, which validate the proposed design method.
2D analytical modeling of a wholly superconducting synchronous reluctance motor
Male, G; Lubin, T; Mezani, S; Leveque, J, E-mail: gael.male@green.uhp-nancy.fr [Groupe de Recherche en Electrotechnique et Electronique de Nancy, Universite Henri Poincare, Faculte des Sciences et Technologies BP 70239, 54506 Vandoeuvre les Nancy CEDEX (France)
2011-03-15
An analytical computation of the magnetic field distribution in a wholly superconducting synchronous reluctance motor is proposed. The stator of the studied motor consists of three-phase HTS armature windings fed by AC currents. The rotor is made with HTS bulks which have a nearly diamagnetic behavior under zero field cooling. The electromagnetic torque is obtained by the interaction between the rotating magnetic field created by the HTS windings and the HTS bulks. The proposed analytical model is based on the resolution of Laplace's and Poisson's equations (by the separation-of-variables technique) for each sub-domain, i.e. stator windings, air-gap, holes between HTS bulks and exterior iron shield. For the study, the HTS bulks are considered as perfect diamagnetic materials. The boundary and continuity conditions between the sub-domains yield to the global solution. Magnetic field distributions and electromagnetic torque obtained by the analytical method are compared with those obtained from finite element analyses.
İhsan Ömür Bucak
2010-03-01
Full Text Available In the automotive industry, electromagnetic variable reluctance (VR sensors have been extensively used to measure engine position and speed through a toothed wheel mounted on the crankshaft. In this work, an application that already uses the VR sensing unit for engine and/or transmission has been chosen to infer, this time, the indirect position of the electric machine in a parallel Hybrid Electric Vehicle (HEV system. A VR sensor has been chosen to correct the position of the electric machine, mainly because it may still become critical in the operation of HEVs to avoid possible vehicle failures during the start-up and on-the-road, especially when the machine is used with an internal combustion engine. The proposed method uses Chi-square test and is adaptive in a sense that it derives the compensation factors during the shaft operation and updates them in a timely fashion.
Bucak, Ihsan Ömür
2010-01-01
In the automotive industry, electromagnetic variable reluctance (VR) sensors have been extensively used to measure engine position and speed through a toothed wheel mounted on the crankshaft. In this work, an application that already uses the VR sensing unit for engine and/or transmission has been chosen to infer, this time, the indirect position of the electric machine in a parallel Hybrid Electric Vehicle (HEV) system. A VR sensor has been chosen to correct the position of the electric machine, mainly because it may still become critical in the operation of HEVs to avoid possible vehicle failures during the start-up and on-the-road, especially when the machine is used with an internal combustion engine. The proposed method uses Chi-square test and is adaptive in a sense that it derives the compensation factors during the shaft operation and updates them in a timely fashion.
Abootorabi Zarchi, H., E-mail: abootorabi9@yahoo.co [Faculty of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Arab Markadeh, Gh.R., E-mail: arab-gh@eng.sku.ac.i [Department of Engineering, Shahrekord University, Shahrekord (Iran, Islamic Republic of); Soltani, J., E-mail: j1234sm@cc.iut.ac.i [Faculty of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)
2010-01-15
In this paper, a nonlinear speed tracking controller is introduced for three-phase synchronous reluctance motor (SynRM) on the basis of input-output feedback linearization (IOFL), considering the different control strategies (maximum torque per Ampere, high efficiency and minimum KVA rating for the inverter) related to this motor. The proposed control approach is capable of decoupling control of stator flux and motor generated torque. The validity and effectiveness of the method is verified by simulation and experimental results.
Rotor Position Estimation for Switched Reluctance Wind Generator Using Extreme Learning Machine
Wang, Chao; Liu, Xiao; Chen, Zhe
2014-01-01
Reluctance Wind Generator (SRWG) based on Extreme Learning Machine (ELM) which could build a nonlinear mapping between flux linkage-current and rotor position. The learning data are derived from magnetization curves of the SRWG which are obtained from Finite Element Analysis (FEA) of an SRG with 8/6 stator...... wind turbines are operating. Fast and accurate rotor position estimation is essential to promote the sensorless control as well as sensor fault tolerant operation of the SRG, which may improve the reliability of the system. This paper presents a rotor position sensorless estimation scheme for Switched...
International Electrotechnical Commission. Geneva
1985-01-01
Applies to three-phase synchronous machines of 1 kVA rating and larger with rated frequency of not more than 400 Hz and not less than 15 Hz. An appendix gives unconfirmed test methods for determining synchronous machine quantities. Notes: 1 -Tests are not applicable to synchronous machines such as permanent magnet field machines, inductor type machines, etc. 2 -They also apply to brushless machines, but certain variations exist and special precautions should be taken.
Modeling of synchronous machines with magnetic saturation
Rehaoulia, H. [Universite de Tunis-Ecole Superieure des Sciences et Techniques de Tunis (Unite de Recherche CSSS), 5 Avenue Taha Hussein Tunis 10008 (Tunisia); Henao, H.; Capolino, G.A. [Universite de Picardie Jules Vernes-Centre de Robotique, d' Electrotechnique et d' Automatique (UPRES-EA3299), 33 Rue Saint Leu, 80039 Amiens Cedex 1 (France)
2007-04-15
This paper deals with a method to derive multiple models of saturated round rotor synchronous machines, based on different selections of state-space variables. By considering the machine currents and fluxes as space vectors, possible d-q models are discussed and adequately numbered. As a result several novel models are found and presented. It is shown that the total number of d-q models for a synchronous machine, with basic dampers, is 64 and therefore much higher than known. Found models are classified into three families: current, flux and mixed models. These latter, the mixed ones, constitute the major part (52) and hence offer a large choice. Regarding magnetic saturation, the paper also presents a method to account for whatever the choice of state-space variables. The approach consists of just elaborating the saturation model with winding currents as main variables and deriving all the other models from it, by ordinary mathematical manipulations. The paper emphasizes the ability of the proposed approach to develop any existing model without exception. An application to prove the validity of the method and the equivalence between all developed models is reported. (author)
Accurate modeling of switched reluctance machine based on hybrid trained WNN
Song, Shoujun; Ge, Lefei; Ma, Shaojie; Zhang, Man
2014-04-01
According to the strong nonlinear electromagnetic characteristics of switched reluctance machine (SRM), a novel accurate modeling method is proposed based on hybrid trained wavelet neural network (WNN) which combines improved genetic algorithm (GA) with gradient descent (GD) method to train the network. In the novel method, WNN is trained by GD method based on the initial weights obtained per improved GA optimization, and the global parallel searching capability of stochastic algorithm and local convergence speed of deterministic algorithm are combined to enhance the training accuracy, stability and speed. Based on the measured electromagnetic characteristics of a 3-phase 12/8-pole SRM, the nonlinear simulation model is built by hybrid trained WNN in Matlab. The phase current and mechanical characteristics from simulation under different working conditions meet well with those from experiments, which indicates the accuracy of the model for dynamic and static performance evaluation of SRM and verifies the effectiveness of the proposed modeling method.
Theoretical evaluation of the double U-core switched reluctance machine
Jæger, Rasmus; Nielsen, Simon Staal; Rasmussen, Peter Omand
2017-01-01
The switched reluctance machine (SRM) has seen a lot of interest due to its simplicity and ruggedness. Much attention have been paid in academia to improve on some of the disadvantages of the technology such as torque ripple, acoustic noise and low torque density. In this paper a topology, namely...... the double U-core SRM, is reviewed. This topology improves on some of the disadvantages of the regular SRM. Torque ripple is reduced and the torque density is increased for the same amount of material, by reconfiguring the topology of the regular SRM and increasing the number of poles. The result...... is a segmented stator structure where each segment can be wound individually and assembled afterwards. Several similar technologies have been demonstrated, and the claimed advantages have been proven in comparison with regular SRMs with a lower pole count. In this paper, the technology will be compared...
Viscoelastic property tuning for reducing noise radiated by switched-reluctance machines
Millithaler, Pierre; Dupont, Jean-Baptiste; Ouisse, Morvan; Sadoulet-Reboul, Émeline; Bouhaddi, Noureddine
2017-10-01
Switched-reluctance motors (SRM) present major acoustic drawbacks that hinder their use for electric vehicles in spite of widely-acknowledged robustness and low manufacturing costs. Unlike other types of electric machines, a SRM stator is completely encapsulated/potted with a viscoelastic resin. By taking advantage of the high damping capacity that a viscoelastic material has in certain temperature and frequency ranges, this article proposes a tuning methodology for reducing the noise emitted by a SRM in operation. After introducing the aspects the tuning process will focus on, the article details a concrete application consisting in computing representative electromagnetic excitations and then the structural response of the stator including equivalent radiated power levels. An optimised viscoelastic material is determined, with which the peak radiated levels are reduced up to 10 dB in comparison to the initial state. This methodology is implementable for concrete industrial applications as it only relies on common commercial finite-element solvers.
Ancuti, Mihaela Codruta; Tutelea, Lucian; Andreescu, Gheorghe-Daniel
2014-01-01
This article introduces a control strategy to obtain near-maximum available torque in a wide speed range with sensorless operation via the active flux concept for permanent magnet-reluctance synchronous motor drives. A new torque dq current reference calculator is proposed, with reference torque...... digital simulation results (1–6000 rpm) and experimental results (50–3000 rpm at low inverter available DC voltage of 12 Vdc instead of 48 Vdc) demonstrate the effectiveness of the proposed sensorless control strategy in a wide speed range, with stable and reliable operations up to a speed equal to eight...
D. Vimalakeerthy,
2011-02-01
Full Text Available Induction Motors(IM are preferred as the most common drive for industrial and civil applications due to their simple construction and robustness. But they are not suitable when the application requires speed regulation. In several cases high torque, high efficiency, and simple controllability are often desired. Permanent Magnet Synchronous Reluctance Motor “PMSRM” has gained interest due to several factors like reduced cost, ability to operate at near zero speed even at full load and flux weakening capability for spindle and traction applications. As the high field strength of neodymium- ron-boron (NdFeB magnets become commercially available with affordable prices, PMSRMs are receiving increasing attention due totheir high speed, high power density and high efficiency. A modified design in the location of permanent magnets in the flux barriers of PMSRM is proposed and its results are validated to improve theperformance. Finite Element Method(FEM is used to analyze the design parameters.
Wen-Bin Lin
2013-01-01
Full Text Available This paper presents the design and implementation of a super-twisting algorithm second-order sliding mode controller (SOSMC for a synchronous reluctance motor. SOSMC is an effective tool for the control of uncertain nonlinear systems since it overcomes the main drawbacks of conventional sliding mode control, that is, large control effort and chattering. The practical implementation of SOSMC has simple control laws and assures an improvement in sliding accuracy with respect to conventional sliding mode control. This paper proposes a control scheme based on super-twisting algorithm SOSMC. The SOSMC is mathematically derived, and its performance is verified by simulation and experiments. The proposed SOSMC is robust against motor parameter variation and mitigates chattering.
Is whole-culture synchronization biology's 'perpetual-motion machine'?
Cooper, Stephen
2004-06-01
Whole-culture or batch synchronization cannot, in theory, produce a synchronized culture because it violates a fundamental law that proposes that no batch treatment can alter the cell-age order of a culture. In analogy with the history of perpetual-motion machines, it is suggested that the study of these whole-culture 'synchronization' methods might lead to an understanding of general biological principles even though these methods cannot be used to study the normal cell cycle.
Vectorial Formalism of Polyphase Synchronous Machine With Permanents Magnets
Nacéra Bachir Bouiadjra
2013-04-01
Full Text Available This paper presents a mathematical model that transforms the real machine to fictitious machines and our goal is to simulate these and see the behavior of these machines in load. The polyphase machines are developed mainly in the field of variable speed drives of high power because increasing the number of phases on the one hand allows to reduce the dimensions of the components in power modulators energy and secondly to improve the operating safety. By a vector approach (vector space, it is possible to find a set of single-phase machine and / or two-phase fictitious equivalent to polyphase synchronous machine. These fictitious machines are coupled electrically and mechanically but decoupled magnetically. This approach leads to introduce the concept of the equivalent machine (multimachine multiconverter system MMS which aims to analyze systems composed of multiple machines (or multiple converters in electric drives. A first classification multimachine multiconverter system follows naturally from MMS formalism. We present an example of a pentaphase (polyphase synchronous machine for a simulation and study the behavior of the machine load
M. Nabil
2012-12-01
Full Text Available This paper presents the performance analysis of a photovoltaic (PV energy source driving a synchronous reluctance (SyncRel motor. The design considerations of the PV array, suitable for driving a centrifugal pump, are studied. Three design approaches are proposed at an average insolation of 0.5 kW/m2. These approaches depend upon determining the system operating point firstly and then maintaining this point on the PV generator characteristics. The first approach takes motor starting current into account as an additional design criterion. The second one is based on achieving the maximum power at the system operating point. The third approach considers maintaining voltage regulation of the PV generator at a pre-specified suitable value. A sample of the simulation results is introduced using the SyncRel motor measured parameters and the estimated parameters of the PV array. It has been found that the minimum number of cells can be achieved using the second approach.
Sensorless Control of Permanent Magnet Synchronous Machines
Matzen, Torben N.
Permanent magnet machines, with either surface mounted or embedded magnets on the rotor, are becoming more common due to the key advantages of higher energy conversion efficiency and higher torque density compared to the classical induction machine. Besides energy efficiency the permanent magnet...... are dependent on the phase currents and rotor position. Based on the flux linkages the differential inductances are determined and used to establish the inductance saliency in terms of ratio and orientation. The orientation and its dependence on the current and rotor position are used to analyse the behaviour...... and establish the suitability of the machine for sensorless control using inductance saliency tracking methods. The same electromagnetic behaviour is used in the implementation of a dynamical simulation model of the machine useful for evaluation of sensorless control methods at the control design stage. Further...
Magnetic equivalent circuit model for unipolar hybrid excitation synchronous machine
Kupiec Emil
2015-03-01
Full Text Available Lately, there has been increased interest in hybrid excitation electrical machines. Hybrid excitation is a construction that combines permanent magnet excitation with wound field excitation. Within the general classification, these machines can be classified as modified synchronous machines or inductor machines. These machines may be applied as motors and generators. The complexity of electromagnetic phenomena which occur as a result of coupling of magnetic fluxes of separate excitation systems with perpendicular magnetic axis is a motivation to formulate various mathematical models of these machines. The presented paper discusses the construction of a unipolar hybrid excitation synchronous machine. The magnetic equivalent circuit model including nonlinear magnetization curves is presented. Based on this model, it is possible to determine the multi-parameter relationships between the induced voltage and magnetomotive force in the excitation winding. Particular attention has been paid to the analysis of the impact of additional stator and rotor yokes on above relationship. Induced voltage determines the remaining operating parameters of the machine, both in the motor and generator mode of operation. The analysis of chosen correlations results in an identification of the effective control range of electromotive force of the machine.
Synchronization of Two Self-Synchronous Vibrating Machines on an Isolation Frame
Chunyu Zhao
2011-01-01
Full Text Available This paper investigates synchronization of two self-synchronous vibrating machines on an isolation rigid frame. Using the modified average method of small parameters, we deduce the non-dimensional coupling differential equations of the disturbance parameters for the angular velocities of the four unbalanced rotors. Then the stability problem of synchronization for the four unbalanced rotors is converted into the stability problems of two generalized systems. One is the generalized system of the angular velocity disturbance parameters for the four unbalanced rotors, and the other is the generalized system of three phase disturbance parameters. The condition of implementing synchronization is that the torque of frequency capture between each pair of the unbalanced rotors on a vibrating machine is greater than the absolute values of the output electromagnetic torque difference between each pair of motors, and that the torque of frequency capture between the two vibrating machines is greater than the absolute value of the output electromagnetic torque difference between the two pairs of motors on the two vibrating machines. The stability condition of synchronization of the two vibrating machines is that the inertia coupling matrix is definite positive, and that all the eigenvalues for the generalized system of three phase disturbance parameters have negative real parts. Computer simulations are carried out to verify the results of the theoretical investigation.
Design and analysis of a transversal-flux switched-reluctance-linear-machine pole-pair
Salo, J.
1999-07-01
The Switched Reluctance technology is probably best suited for industrial low-speed or zerospeed applications where the power can be small but the torque or the force in linear movement cases might be relatively high. Because of its simple structure the Sit-motor is an interesting alternative for low power applications where pneumatic or hydraulic linear drives are to be avoided. This study analyses the basic parts of an LSR-motor which are the two mover poles and one stator pole and which form the 'basic pole pair' in linear-movement transversal-flux switched-reluctance motors. The static properties of the basic pole pair are modelled and the basic design rules are derived. The models developed are validated with experiments. A one-sided one-polepair transversal-flux switched-reluctance-linear-motor prototype is demonstrated and its static properties are measured. The modelling of the static properties is performed with FEM-calculations. Two-dimensional models are accurate enough to model the static key features for the basic dimensioning of LSRmotors. Three-dimensional models must be used in order to get the most accurate calculation results of the static traction force production. The developed dimensioning and modelling methods, which could be systematically validated by laboratory measurements, are the most significant contributions of this thesis. (orig.)
Dynamic study of synchronous machine electric drive
Dimitar Spirov
2005-10-01
Full Text Available The dynamic behaviour of the fan blower synchoronous machine drive have been studied in the paper. The equations for the voltages of the synchoronous machine windings are presented in a coordinate system which rotates at the angular speed of the rotor. The mechanical equipment is presented by means of a single-mass dynamic model. The derived system of differential equations is transformed and solved using suitable software product. The results obtained for rotation frequency and electromagnetic torque motor in the courses of different values of rated supply voltage and of different initial resistant moment of the mechanism have been graphically presented. Conclusions from the results obtained have been done.
Mobile virtual synchronous machine for vehicle-to-grid applications
Pelczar, Christopher
2012-03-20
The Mobile Virtual Synchronous Machine (VISMA) is a power electronics device for Vehicle to Grid (V2G) applications which behaves like an electromechanical synchronous machine and offers the same beneficial properties to the power network, increasing the inertia in the system, stabilizing the grid voltage, and providing a short-circuit current in case of grid faults. The VISMA performs a real-time simulation of a synchronous machine and calculates the phase currents that an electromagnetic synchronous machine would produce under the same local grid conditions. An inverter with a current controller feeds the currents calculated by the VISMA into the grid. In this dissertation, the requirements for a machine model suitable for the Mobile VISMA are set, and a mathematical model suitable for use in the VISMA algorithm is found and tested in a custom-designed simulation environment prior to implementation on the Mobile VISMA hardware. A new hardware architecture for the Mobile VISMA based on microcontroller and FPGA technologies is presented, and experimental hardware is designed, implemented, and tested. The new architecture is designed in such a way that allows reducing the size and cost of the VISMA, making it suitable for installation in an electric vehicle. A simulation model of the inverter hardware and hysteresis current controller is created, and the simulations are verified with various experiments. The verified model is then used to design a new type of PWM-based current controller for the Mobile VISMA. The performance of the hysteresis- and PWM-based current controllers is evaluated and compared for different operational modes of the VISMA and configurations of the inverter hardware. Finally, the behavior of the VISMA during power network faults is examined. A desired behavior of the VISMA during network faults is defined, and experiments are performed which verify that the VISMA, inverter hardware, and current controllers are capable of supporting this
Xu LIU; Zai-ping PAN; Z.Q. ZHU
2010-01-01
This paper proposes an analytical model for predicting the maximum vibration reduction level in a four-phase 8/6switched reluctance machine(SRM)by employing active vibration cancellation(AVC),one of the most effective and convenient methods for reducing the vibration and acoustic noise produced by SRMs.Based on the proposed method,the factors that influence the vibration reduction level are analyzed in detail.The relationships between vibration and noise reduction levels at resonance frequency and rotor speed are presented.Moreover,it is shown that a large damping factor will lead to smaller vibration reduction level with AVC while,in contrast,a large resonance frequency will increase the vibration reduction level.Both finite element analyses and experiments were carried out on a prototype 8/6 SRM to validate the proposed method.
High performance self-excited reluctance generator for mini/micro hydro electric power generation
Srivastava, A.; Goel, S.K. [G.B.P.U.A. and T, Pantnagar (India). Dept. of Electrical Engineering
2007-07-01
Recent interest in the synchronous reluctance generator has increased because it offers the solution to the problems faced by induction generators while including almost all of the benefits of induction machines. This paper discussed the development of a mathematical model of a self excited synchronous reluctance generator using Park's transformation which can be used to obtain its performance by simulation. Almost all of the important performance parameters of reluctance machine depend on the saliency ratio .The paper focused on the fabrication, design and testing of an axially laminated anisotropic (ALA) rotor self-excited reluctance generator. The paper discussed SRM as a self-excited generator; maximization of saliency ratio; the assumptions made in obtaining the mathematical model of SRM; the laboratory machine; and results and discussion. It was concluded that compared to other rotor configurations, the ALA rotor with high saliency ratio performed better. 6 refs., 12 figs.
Machine Translation Using Constraint-Based Synchronous Grammar
WONG Fai; DONG Mingchui; HU Dongcheng
2006-01-01
A synchronous grammar based on the formalism of context-free grammar was developed by generalizing the first component of production that models the source text. Unlike other synchronous grammars,the grammar allows multiple target productions to be associated to a single production rule which can be used to guide a parser to infer different possible translational equivalences for a recognized input string according to the feature constraints of symbols in the pattern. An extended generalized LR algorithm was adapted to the parsing of the proposed formalism to analyze the syntactic structure of a language. The grammar was used as the basis for building a machine translation system for Portuguese to Chinese translation. The empirical results show that the grammar is more expressive when modeling the translational equivalences of parallel texts for machine translation and grammar rewriting applications.
Chen Haijin [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China); Jiang-Su Provincial Key Lab of ASIC Design, Nantong University, Nantong 226019 (China)], E-mail: chen.hj@ntu.edu.cn; Lu Shengli; Shi Longxing [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)
2009-03-15
A general-purpose application specific integrated circuit (ASIC) chip for the control of switched reluctance machines (SRMs) was designed and validated to fill the gap between the microcontroller capability and the controller requirements of high performance switched reluctance drive (SRD) systems. It can be used for the control of SRM running either in low speed or in high-speed, i.e., either in chopped current control (CCC) mode or in angular position control (APC) mode. Main functions of the chip include filtering and cycle calculation of rotor angular position signals, commutation logic according to rotor cycle and turn-on/turn-off angles ({theta}{sub on}/{theta}{sub off}), controllable pulse width modulation (PWM) waveforms generation, chopping control with adjustable delay time, and commutation control with adjustable delay time. All the control parameters of the chip are set online by the microcontroller through a serial peripheral interface (SPI). The chip has been designed with the standard cell based design methodology, and implemented in the central semiconductor manufacturing corporation (CSMC) 0.5 {mu}m complementary metal-oxide-semiconductor (CMOS) process technology. After a successful automatic test equipment (ATE) test using the Nextest's Maverick test system, the chip was further validated through an experimental three-phase 6/2-pole SRD system. Both the ATE test and experimental validation results show that the chip can meet the control requirements of high performance SRD systems, and simplify the controller construction. For a resolution of 0.36 deg. (electrical degree), the chip's maximum processable frequency of the rotor angular position signals is 10 kHz, which is 300,000 rev/min when a three-phase 6/2-pole SRM is concerned.
Chen, Hai-Jin [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)]|[Jiang-Su Provincial Key Lab of ASIC Design, Nantong University, Nantong 226019 (China); Lu, Sheng-Li; Shi, Long-Xing [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)
2009-03-15
A general-purpose application specific integrated circuit (ASIC) chip for the control of switched reluctance machines (SRMs) was designed and validated to fill the gap between the microcontroller capability and the controller requirements of high performance switched reluctance drive (SRD) systems. It can be used for the control of SRM running either in low speed or in high-speed, i.e., either in chopped current control (CCC) mode or in angular position control (APC) mode. Main functions of the chip include filtering and cycle calculation of rotor angular position signals, commutation logic according to rotor cycle and turn-on/turn-off angles ({theta}{sub on}/{theta}{sub off}), controllable pulse width modulation (PWM) waveforms generation, chopping control with adjustable delay time, and commutation control with adjustable delay time. All the control parameters of the chip are set online by the microcontroller through a serial peripheral interface (SPI). The chip has been designed with the standard cell based design methodology, and implemented in the central semiconductor manufacturing corporation (CSMC) 0.5 {mu}m complementary metal-oxide-semiconductor (CMOS) process technology. After a successful automatic test equipment (ATE) test using the Nextest's Maverick test system, the chip was further validated through an experimental three-phase 6/2-pole SRD system. Both the ATE test and experimental validation results show that the chip can meet the control requirements of high performance SRD systems, and simplify the controller construction. For a resolution of 0.36 (electrical degree), the chip's maximum processable frequency of the rotor angular position signals is 10 kHz, which is 300,000 rev/min when a three-phase 6/2-pole SRM is concerned. (author)
Theoretical analysis of control properties for the brushless doubly fed reluctance machine
Betz, Robert; Jovanovic, Milutin
2002-01-01
Presents the fundamental theory, modelling aspects and operating/control principles of the BDFRM. This emerging machine technology is being regarded by academic and industrial communities as a prospective brushless candidate for wind turbine generators (especially off-shore installations) and large pump drives where it can offer reliable, maintenance-free, operation and competitive performance at low cost due to the use of a smaller inverter. The results in the paper are the outcomes of a joi...
Tounzi, A.; Meibody-Tabar, F.; Sargos, F.
1997-01-01
This paper deals with the field-oriented control of a smooth stator, non excited salient rotor synchronous machine. First, a nonlinear modelling of the machine, taking into account both damping and saturation effects, is developed in PARK's rotor-bound frame. Then, a vector control strategy, which maintains a constant saturation level in the machine, is set-up. This strategy, wich consists in keeping the stator direct current at a high constant value, allows to linearize the model of the mach...
Optimal Design Solutions for Permanent Magnet Synchronous Machines
POPESCU, M.
2011-11-01
Full Text Available This paper presents optimal design solutions for reducing the cogging torque of permanent magnets synchronous machines. A first solution proposed in the paper consists in using closed stator slots that determines a nearly isotropic magnetic structure of the stator core, reducing the mutual attraction between permanent magnets and the slotted armature. To avoid complications in the windings manufacture technology the stator slots are closed using wedges made of soft magnetic composite materials. The second solution consists in properly choosing the combination of pole number and stator slots number that typically leads to a winding with fractional number of slots/pole/phase. The proposed measures for cogging torque reduction are analyzed by means of 2D/3D finite element models developed using the professional Flux software package. Numerical results are discussed and compared with experimental ones obtained by testing a PMSM prototype.
Efficient operation of anisotropic synchronous machines for wind energy systems
Eldeeb, Hisham; Hackf, Christoph M.; Kullick, Julian
2016-09-01
This paper presents an analytical solution for the Maximum-Torque-per-Ampere (MTPA) operation of synchronous machines (SM) with anisotropy and magnetic cross-coupling for the application in wind turbine systems and airborne wind energy systems. For a given reference torque, the analytical MTPA solution provides the optimal stator current references which produce the desired torque while minimizing the stator copper losses. From an implementation point of view, the proposed analytical method is appealing in terms of its fast online computation (compared to classical numerical methods) and its efficiency enhancement of the electrical drive system. The efficiency of the analytical MTPA operation, with and without consideration of cross-coupling, is compared to the conventional method with zero direct current.
Modelling and Simulation of a Synchronous Machine with Power Electronic Systems
Chen, Zhe; Blaabjerg, Frede
2005-01-01
This paper reports the modeling and simulation of a synchronous machine with a power electronic interface in direct phase model. The implementation of a direct phase model of synchronous machines in MATLAB/SIMULINK is presented .The power electronic system associated with the synchronous machine...... is modelled in SIMULINK as well. The resulting model can more accurately represent non-idea situations such as non-symmetrical parameters of the electrical machines and unbalance conditions. The model may be used for both steady state and large-signal dynamic analysis. This is particularly useful...
Modelling and Simulation of a Synchronous Machine with Power Electronic Systems
Chen, Zhe; Blaabjerg, Frede
2005-01-01
This paper reports the modeling and simulation of a synchronous machine with a power electronic interface in direct phase model. The implementation of a direct phase model of synchronous machines in MATLAB/SIMULINK is presented .The power electronic system associated with the synchronous machine...... is modelled in SIMULINK as well. The resulting model can more accurately represent non-idea situations such as non-symmetrical parameters of the electrical machines and unbalance conditions. The model may be used for both steady state and large-signal dynamic analysis. This is particularly useful...
Methods, systems and apparatus for synchronous current regulation of a five-phase machine
Gallegos-Lopez, Gabriel; Perisic, Milun
2012-10-09
Methods, systems and apparatus are provided for controlling operation of and regulating current provided to a five-phase machine when one or more phases has experienced a fault or has failed. In one implementation, the disclosed embodiments can be used to synchronously regulate current in a vector controlled motor drive system that includes a five-phase AC machine, a five-phase inverter module coupled to the five-phase AC machine, and a synchronous current regulator.
Wu, Wenye; Zhu, Xiaoyong; Quan, Li; Fan, Deyang; Xiang, Zixuan
2017-05-01
Low-energy permanent magnet (PM) such as ferrite is usually adopted in a PM-assisted reluctance (PMAREL) motor to enhance the output torque and reduce costs. However, the relatively low magnetic energy product and remanence in such PMs may lead to the risk of demagnetization. By using two types of materials of rare-earth NdFeB and non-rare-earth ferrite PM, a new less-rare-earth hybrid PMAREL motor is proposed in this paper, where the output torque and the power factor can be improved obviously, and meanwhile the risk of irreversible demagnetization in ferrite PMs can be reduced significantly due to the existence of NdFeB PMs. To verify the validity of the proposed motor, the operating principles of the motor and the positive interaction influences between the two involved types of PMs are analyzed. Moreover, by using the finite element method, the torque characteristics and anti-demagnetization capabilities are also investigated in details. Both the theoretical analysis and simulated results confirm the advantages of the proposed motor.
Recent Advances on Permanent Magnet Machines
诸自强
2012-01-01
This paper overviews advances on permanent magnet（PM） brushless machines over last 30 years,with particular reference to new and novel machine topologies.These include current states and trends for surface-mounted and interior PM machines,electrically and mechanically adjusted variable flux PM machines including memory machine,hybrid PM machines which uniquely integrate PM technology into induction machines,switched and synchronous reluctance machines and wound field machines,Halbach PM machines,dual-rotor PM machines,and magnetically geared PM machines,etc.The paper highlights their features and applications to various market sectors.
Design of rotating electrical machines
Pyrhonen , Juha; Hrabovcova , Valeria
2013-01-01
In one complete volume, this essential reference presents an in-depth overview of the theoretical principles and techniques of electrical machine design. This timely new edition offers up-to-date theory and guidelines for the design of electrical machines, taking into account recent advances in permanent magnet machines as well as synchronous reluctance machines. New coverage includes: Brand new material on the ecological impact of the motors, covering the eco-design principles of rotating electrical machinesAn expanded section on the design of permanent magnet synchronous machines, now repo
M. K. Metwally
2013-11-01
Full Text Available This paper presents a cost-effective vector control strategy for four switch three phase (FSTP inverter fed a synchronous reluctance motor with conventional rotor (SynRM drive. The reduction of the number of power switches from six to four improves the cost-effectiveness, volume-compactness and reliability of the three phase inverters. In this paper, a simulation model of the drive system is developed and analyzed in order to verify the effectiveness of the approach. The application of vector control to a SynRM at maximum torque control (MTC operation is presented with emphasis on the effects of saturation and iron losses are briefly considered. A PI controller is used to process the speed error. Two independent hysteresis current controllers with a suitable hysteresis band are utilized for inverter switches signals. A simplified steady-state d-q model including saturation and iron losses is presented. Simulation results show that the drive system provides a fast speed response and good disturbance rejection capability.
Abdelkrim Sellam
2012-12-01
Full Text Available The polyphase [1] machines are developed mainly in the field of variable speed drives of high power because increasing the number of phases on the one hand allows to reduce the dimensions of the components in power modulators energy and secondly to improve the operating safety. By a vector approach (vector space, it is possible to find a set of single-phase machine and / or two-phase fictitious equivalent to polyphase synchronous machine.These fictitious machines are coupled electrically and mechanically but decoupled magnetically. This approach leads to introduce the concept of the equivalent machine (multimachine multiconverter system MMS which aims to analyze systems composed of multiple machines (or multiple converters in electric drives. A first classification multimachine multiconverter system follows naturally from MMS formalism. We present an example of a synchronous machine pent phase.
Self-commissioning of permanent magnet synchronous machine drives using hybrid approach
Basar, M. Sertug; Bech, Michael Møller; Andersen, Torben Ole
2014-01-01
Self-commissioning of permanent-magnet (PM) synchronous machines (PMSMs) is of prime importance in an industrial drive system because control performance and system stability depend heavily on the accurate machine parameter information. This article focuses on a combination of offline and online ...
Gündoğdu, Tayfun; Kömürgöz, Güven
2012-08-01
Chinese export restrictions already reduced the planning reliability for investments in permanent magnet wind turbines. Today the production of permanent magnets consumes the largest proportion of rare earth elements, with 40% of the rare earth-based magnets used for generators and other electrical machines. The cost and availability of NdFeB magnets will likely determine the production rate of permanent magnet generators. The high volatility of rare earth metals makes it very difficult to quote a price. Prices may also vary from supplier to supplier to an extent of up to 50% for the same size, shape and quantity with a minor difference in quality. The paper presents the analysis and the comparison of salient pole with field winding and of peripheral winding synchronous electrical machines, presenting important advantages. A neodymium alloy magnet rotor structure has been considered and compared to the salient rotor case. The Salient Pole Synchronous Machine and the Permanent Magnet Synchronous Machine were designed so that the plate values remain constant. The Eddy current effect on the windings is taken into account during the design, and the efficiency, output power and the air-gap flux density obtained after the simulation were compared. The analysis results clearly indicate that Salient Pole Synchronous Machine designs would be attractive to wind power companies. Furthermore, the importance of the design of electrical machines and the determination of criteria are emphasized. This paper will be a helpful resource in terms of examination and comparison of the basic structure and magnetic features of the Salient Pole Synchronous Machine and Permanent Magnet Synchronous Machine. Furthermore, an economic analysis of the designed machines was conducted.
Simulating the effect of SFCL on limiting the internal fault of synchronous machine
Kheirizad, I [Islamic Republic of Iran Broadcasting, Tehran (Iran, Islamic Republic of); Varahram, M H [Ministry of Science, Research and Technology, Tehran (Iran, Islamic Republic of); Jahed-Motlagh, M R [Azad University of Science and Research, Tehran (Iran, Islamic Republic of); Rahnema, M; Mohammadi, A [Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)], E-mail: hadi_varahram@yahoo.com
2008-02-01
In this paper, we have modelled a synchronous generator with internal one phase to ground fault and then the performance of this machine with internal one phase to ground fault have been analyzed. The results show that if the faults occur in vicinity of machine's terminal, then we would have serious damages. To protect the machine from this kind of faults we have suggested integrating a SFCL (superconducting fault current limiter) into the machine's model. The results show that the fault currents in this case will reduce considerably without influencing the normal operation of the machine.
Etude et simulation des groupes convertisseurs-machines synchrones a six phases
Doyon, Jean-Francois
Since many years, multiphase (n > 3) machines represent a growing research interest in the electrical machines domain. This type of machine can be used for many systems like automotive electrical traction, electric ship propulsion, wind farms or high-power industrial applications. Above all multiphase machines, the six phases wounded rotor synchronous machine brings a huge interest. Subsequently, using that kind of machine in any application requires a good understanding of the machine model and its respective converters. Hence, simulation represents a great way to study the behaviour and design of such applications that uses six phases wounded rotor synchronous machines. The present research concerns the study and simulation of six phase synchronous machinesconverters systems. From this project resulted the implementation of the six phases wound rotor salient pole synchronous machine in the Demos library of Matlab SimPowerSytems. In terms of study, a six phase machine electric drive is designed as well as a six phase machine implementation in a type 4 wind farm. The modeling of the six phase synchronous machine is fully detailed for the electrical part and the mechanical part. Then, the voltage source inverter electric drive with hysteresis control is conceived. Simulations of torque control, speed control and degraded mode of the machine are executed. The results illustrate the electric drive efficiency. This is followed by the type 4 wind turbine application of the machine. The wind farm is connected to a 120 kV grid, where a voltage drop fault appears at the 120 kV bar for a duration of six 60 Hz cycles. The results show a good operation of the regulators during the fault. This application is also subjected to a degraded mode, where results illustrate once again a good system regulation. Also, for the electric drive and the wind farm applications, a comparative study is made for the use of an asymmetrical versus symmetrical winding configuration of the machine
Design and Modeling of High Performance Permanent Magnet Synchronous Machines
Van der Geest, M.
2015-01-01
The electrification of transportation, and especially aerospace transportation, increases the demand for high performance electrical machines. Those machines often need to be fault-tolerant, cheap, highly efficient, light and small, and interface well with the inverter. In addition, the development
Topology Optimization of a High-Temperature Superconducting Field Winding of a Synchronous Machine
Pozzi, Matias; Mijatovic, Nenad; Jensen, Bogi Bech
2013-01-01
genetic algorithm with local optimization search based on on/off sensitivity analysis. The results show an optimal HTS coil distribution, achieving compact designs with a maximum of approximately 22% of the available space for the field winding occupied with HTS tape. In addition, this paper describes......This paper presents topology optimization (TO) of the high-temperature superconductor (HTS) field winding of an HTS synchronous machine. The TO problem is defined in order to find the minimum HTS material usage for a given HTS synchronous machine design. Optimization is performed using a modified...
Ge Zhengming [Department of Mechanical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan (China)]. E-mail: zmg@cc.nctu.edu.tw; Lee, Ching-I [Department of Mechanical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan (China)
2005-03-01
Chaos, control, anticontrol and synchronization of chaos for an autonomous rotational machine system with a hexagonal centrifugal governor and spring for which time-delay effect is considered are studied in the paper. By applying numerical results, phase diagram and power spectrum are presented to observe periodic and chaotic motions. Linear feedback control and adaptive control algorithm are used to control chaos effectively. Linear and nonlinear feedback synchronization and phase synchronization for the coupled systems are presented. Finally, anticontrol of chaos for this system is also studied.
Abdelkrim Sellam,Boubakeur Dehiba,Mohamed B. Benabdallah,Mohamed Abid,Nacéra Bachir Bouiadjra,Boubakeur Bensaid,Mustapha Djouhri
2012-12-01
Full Text Available The polyphase [1] machines are developed mainly inthe field of variable speed drives of high powerbecause increasing the number of phases on the onehand allows to reduce the dimensions of thecomponents in power modulators energy and secondlyto improve the operating safety. By a vector approach(vector space, it is possible to find a set of singlephasemachine and / or two-phase fictitious equivalentto polyphase synchronous machine.These fictitiousmachines are coupled electrically and mechanicallybut decoupled magnetically. This approach leads tointroduce the concept of the equivalent machine(multimachine multiconverter system MMS whichaims to analyze systems composed of mul tiplemachines (or multiple converters in electric drives. Afirst classification multimachine multiconvertersystem follows naturally from MMS formalism. Wepresent an example of a synchronous machine pent
Impact of Model Detail of Synchronous Machines on Real-time Transient Stability Assessment
Weckesser, Johannes Tilman Gabriel; Jóhannsson, Hjörtur; Østergaard, Jacob
2013-01-01
to identify the transient stability mechanism, a simulation with a high-order model was used as reference. The Western System Coordinating Council System (WSCC) and the New England & New York system are considered and simulations of an unstable and a stable scenario are carried out, where the detail......In this paper, it is investigated how detailed the model of a synchronous machine needs to be in order to assess transient stability using a Single Machine Equivalent (SIME). The results will show how the stability mechanism and the stability assessment are affected by the model detail. In order...... of the machine models is varied. Analyses of the results suggest that a 4th-order model may be sufficient to represent synchronous machines in transient stability studies....
Tounzi, A.; Meibody-Tabar, F.; Sargos, F. M.
1997-04-01
This paper deals with the field-oriented control of a smooth stator, non excited salient rotor synchronous machine. First, a nonlinear modelling of the machine, taking into account both damping and saturation effects, is developed in PARK's rotor-bound frame. Then, a vector control strategy, which maintains a constant saturation level in the machine, is set-up. This strategy, wich consists in keeping the stator direct current at a high constant value, allows to linearize the model of the machine and to control it in the same way as a DC machine. A numerical simulation of a VRM, fed by a PWM-VSI and controlled thanks to this control strategy, is built up and the computed results are given and commented. Cet article est consacré à la commande vectorielle d'une machine à réluctance variable à stator lisse et rotor massif. D'abord, une modélisation non linéaire de la machine a été effectuée dans le repère de Park. Cette dernière permet de prendre en compte l'effet d'amortissement dû au rotor massif, ainsi que celui de la saturation inhérent à ce genre de machine. Ensuite, une stratégie de contrôle vectoriel, qui maintient un niveau de saturation constant dans la machine, a été élaborée. Cette stratégie, qui consiste à maintenir le courant direct statorique à une valeur élevée, permet de linéariser le modèle de la machine et ainsi de pouvoir la contrôler comme une machine à courant continu. Une simulation numérique de la machine à réluctance variable, alimentée par un onduleur de tension à MLI et commandée par la stratégie mise au point, a été effectuée. Les résultats de cette simulation sont donnés et commentés à la fin de l'article.
Energy-saving operation of a converter-fed synchronous machine
Schmidt, I.; Veszpremi, K. [Technical University of Budapest, Department of Electrical Machines and Drives, Budapest (Hungary)
1997-12-31
In the Converter-Fed Synchronous Machine (CFSM) there is no need for forced commutation the CL and CF converters operate with line commutation, the CM is commutated by the machine voltages. This drive is applied mainly for large power and high speed controlled drives. Considering the large power, the investigation of energy-saving operation is important. As in the DC and the induction motor drives the energy-saving operation is implemented by flux control. (orig.) 6 refs.
COMMANDE NON LINEAIRE SANS CAPTEUR DE LA MACHINE SYNCHRONE A AIMANTS PERMANENTS
Ezzat, Marwa
2011-01-01
The permanent magnet synchronous motor when compared to other electric machines, is very present in motion control industrial applications. This is mainly because of its compactness, low inertia, dynamics performances, robustness, power density and simplicity of operation with mechanical sensor. However, sensorless control of this machine is always a difficult problem because of the observability loss problem. The aim of this thesis is to propose control laws for mechanical sensorless permane...
Script Controlled Modeling of Low Noise Permanent Magnet Synchronous Machines by using JMAG Designer
RUSU Tiberiu; BÎRTE Ovidiu; SZABÓ Loránd; MARŢIŞ Claudia Steluţa
2013-01-01
This paper deals with the parameterizedmodeling of permanent magnet synchronous machines(PMSM) by means of JMAG Designer, an advancedsimulation software for electromechanical design. Thismethod enables the designer to simulate diverse topologies ofthe machines by only changing some basic parameters of thescript controlling the preprocessing phase of the simulations.For this purpose a graphical user interface for modeling themachine was built up in Visual Basic. Thru it the users canenter the ...
Influence of Voltage Dips on the Operation of Brushless Exciter System of Synchronous Machines
Fedotov, A.; Leonov, A.; Vagapov, G.; Mutule, A.
2016-06-01
This paper presents a mathematical model with continuous variables for brushless exciter system of synchronous machines, containing the thyristor elements. Discrete Laplace transform is used for transition from a mathematical model of a system with variable structure in continuous variables to equation finite difference with permanent structure. Then inverse transition is made to a mathematical model in continuous variables with permanent structure.
A Virtual Inertia Control Strategy for DC Microgrids Analogized with Virtual Synchronous Machines
Wu, Wenhua; Chen, Yandong; Luo, An;
2017-01-01
synchronous machine (VSM) is proposed to enhance the inertia of the DC-MG, and to restrain the dc bus voltage fluctuation. The small-signal model of the BGC system is established, and the small-signal transfer function between the dc bus voltage and the dc output current of the BGC is deduced. The dynamic...
Prediction of chaos in non-salient permanent-magnet synchronous machines
Rasoolzadeh, Arsalan; Tavazoei, Mohammad Saleh
2012-12-01
This Letter tries to find the area in parameter space of a non-salient Permanent-Magnet Synchronous Machine (PMSM) in which chaos can occur. This area is briefly named as chaotic area. The predicted chaotic area is obtained by checking some conditions which are necessary for existence of chaos in a dynamical system. In this Letter, it is assumed that this machine is in the generator mode, and its model is based on direct and quadrature axis of stator voltages and currents. The information of the predicted area is used in non-chaotic maximum power control of torque in the machine.
Chaos Control in Synchronous Reluctance Motors Using the LaSalle Theory%基于拉萨尔不变集定理控制同步磁阻电动机的混沌振荡
李健昌; 韦笃取; 张波
2013-01-01
A new strategy for chaos control was investigated using the LaSalle's invariant theory. This strategy was free of the effect of uncertain equilibria in the synchronous reluctance motor. The accuracy and validity of the proposed control method were approved by the results of simulation analysis. The strategy can automatically find the balance point of the system and work when the motor balance point is unknown, so the principle is simple, direct and favorable to practical application. The study results are helpful for maintaining the secure operation of synchronous reluctance motor.%首先基于拉萨尔(LaSalle)不变集定理提出一种新的控制方法,然后证明混沌同步磁阻电动机(Syn-RMs)在该控制器作用下达到稳定.由于该控制方法能自动识别系统平衡点,在电机平衡点位置未知的情况下仍然有效,因此控制器设计原理简洁直接,有利于实际应用.研究结果对保证SynRMs的可靠运行具有重要意义.
Designing Of Permanent Magnet Synchronous Machine For Applications In Small Hydro Power Plants
Jayashree Sharma
2015-07-01
Full Text Available The need of the hour, as we all genuinely know from the global scenario is the production of electricity from the renewable resources of energy. Most widely used among them are the solar and the wind potential. Besides these, the hydroelectric resources also play a remarkable role as hydroelectricity accounts for a major share in the energy sector throughout the world. The trend at present is of the stand alone hydro power plants wherein the turbine used is the Hydrokinetic turbine , which works with the speed of flow of the water stream. Permanent magnet synchronous machines, known for their robust nature, variable speed, and high power to weight ratio are the most suitable ones for the construction of the turbine for low speed operation. This paper presents the design of permanent magnet synchronous machine and the machine has been modeled and simulated in RMXprt and Ansys Maxwell.
Effects of pole flux distribution in a homopolar linear synchronous machine
Balchin, M. J.; Eastham, J. F.; Coles, P. C.
1994-05-01
Linear forms of synchronous electrical machine are at present being considered as the propulsion means in high-speed, magnetically levitated (Maglev) ground transportation systems. A homopolar form of machine is considered in which the primary member, which carries both ac and dc windings, is supported on the vehicle. Test results and theoretical predictions are presented for a design of machine intended for driving a 100 passenger vehicle at a top speed of 400 km/h. The layout of the dc magnetic circuit is examined to locate the best position for the dc winding from the point of view of minimum core weight. Measurements of flux build-up under the machine at different operating speeds are given for two types of secondary pole: solid and laminated. The solid pole results, which are confirmed theoretically, show that this form of construction is impractical for high-speed drives. Measured motoring characteristics are presented for a short length of machine which simulates conditions at the leading and trailing ends of the full-sized machine. Combination of the results with those from a cylindrical version of the machine make it possible to infer the performance of the full-sized traction machine. This gives 0.8 pf and 0.9 efficiency at 300 km/h, which is much better than the reported performance of a comparable linear induction motor (0.52 pf and 0.82 efficiency). It is therefore concluded that in any projected high-speed Maglev systems, a linear synchronous machine should be the first choice as the propulsion means.
Single bus star connected reluctance drive and method
Fahimi, Babak; Shamsi, Pourya
2016-05-10
A system and methods for operating a switched reluctance machine includes a controller, an inverter connected to the controller and to the switched reluctance machine, a hysteresis control connected to the controller and to the inverter, a set of sensors connected to the switched reluctance machine and to the controller, the switched reluctance machine further including a set of phases the controller further comprising a processor and a memory connected to the processor, wherein the processor programmed to execute a control process and a generation process.
Multiphysics Modeling of an Permanent Magnet Synchronous Machine
MARTIS Claudia
2012-10-01
Full Text Available This paper analyzes the noise and vibration in PMSMs. There are three types of vibrations in electrical machines: electromagnetic,mechanical and aerodynamic. Electromagnetic force are the main cause of noise and vibration in PMSMs. It is very important to calculate precisely the natural frequencies of the stator system. If oneradial force (which are the main cause for electromagnetic vibration has the frequency close to the natural frequency of the stator system for the same order of vibrational mode, then this force canproduce dangerous vibration in the stator system. The natural frequencies for a stator system of a PMSM have been calculated. Finally a Structural Analysis has been made , pointing out the radialdisplacement and stress for the chosen PMSM .
Zhang, Xiaoxu; Liu, Xiao; Liu, Jinglin;
2015-01-01
Flux-modulated permanent-magnet synchronous machine (FM-PMSM) is characterized as a high-torque direct-drive electrical machine, but may suffer from the low power factor. This paper aims to investigate the issue of the low power factor in theory and explore the possibilities for improvement....... An analytical model for the FM-PMSM is developed to obtain the magnetic field distribution, and its accuracy is verified by the finite-element method. On the basis of the developed analytical model, a fast approach is developed to predict the power factor of the FM-PMSM. The analytical results indicate...
Identification and non-integer order modelling of synchronous machines operating as generator
Szymon Racewicz
2012-09-01
Full Text Available This paper presents an original mathematical model of a synchronous generator using derivatives of fractional order. In contrast to classical models composed of a large number of R-L ladders, it comprises half-order impedances, which enable the accurate description of the electromagnetic induction phenomena in a wide frequency range, while minimizing the order and number of model parameters. The proposed model takes into account the skin eff ect in damper cage bars, the eff ects of eddy currents in rotor solid parts, and the saturation of the machine magnetic circuit. The half-order transfer functions used for modelling these phenomena were verifi ed by simulation of ferromagnetic sheet impedance using the fi nite elements method. The analysed machine’s parameters were identified on the basis of SSFR (StandStill Frequency Response characteristics measured on a gradually magnetised synchronous machine.
Vazquez, C.
2006-07-01
The ACE2 project deals with the development of a kynetic energy storage (KES) system for power peak shaving in high speed railway substations. This KES system consists in a double power converter which drives a switched reluctance machine (SRM) along with a flywheel operating in a wide speed range. This document presents from a technical point of view the features of the controller for the machine-side power converter of a 2kW SRM prototype. Hardware and software issues are treated in detail. (Author)
Vazquez, C.
2006-12-19
The ACE2 project deals with the development of a kynetic energy storage (KES) system for power peak shaving in high speed railway substations. This KES system consists in a double power converter which drives a switched reluctance machine (SRM) along with a flywheel operating in a wide speed range. This document presents from a technical point of view the features of the controller for the machine-side power converter of a 2kW SRM prototype. Hardware and software issues are treated in detail. (Author)
Liang, Wenyi
2017-01-01
The rising public awareness of climate change and urban air pollution has been one of the key drivers for transport electrification. Such trend drastically accelerates the quest for high-power-and-torque-density electric drive systems. The rare-earth permanent magnet synchronous machine, with its excellent steady-state and dynamic characteristics, has been the ideal candidate for these applications. Specifically, the fractional-slot and concentrated-winding configuration is wid...
Influence of Voltage Dips on the Operation of Brushless Exciter System of Synchronous Machines
Fedotov A.
2016-06-01
Full Text Available This paper presents a mathematical model with continuous variables for brushless exciter system of synchronous machines, containing the thyristor elements. Discrete Laplace transform is used for transition from a mathematical model of a system with variable structure in continuous variables to equation finite difference with permanent structure. Then inverse transition is made to a mathematical model in continuous variables with permanent structure.
Amara, Y.
2001-12-01
Double excitation machines are synchronous machines where two excitation circuits coexist: one with permanent magnets and the other with windings. This study shows that double excitation allows to combine the advantages of synchronous machines with winded inductor with those of permanent magnet machines. This concept allows a better dimensioning of the converter-machine set and a better energy management. In order to allow the operation of permanent magnet machines over a wide range of speeds, it is necessary to have a magnetic reaction of the induced circuit of the same order than the excitation flux. On the other hand, the power factor is weaker and the power supply converter is over-dimensioned. The double excitation allows the permanent magnet machines to work over a large speed range with a better power factor, even when the magnetic reaction of the induced circuit is relatively weak with respect to the excitation flux. (J.S.)
A Novel Cogging Torque Simulation Method for Permanent-Magnet Synchronous Machines
Chun-Yu Hsiao
2011-12-01
Full Text Available Cogging torque exists between rotor mounted permanent magnets and stator teeth due to magnetic attraction and this is an undesired phenomenon which produces output ripple, vibration and noise in machines. The purpose of this paper is to study the existence and effects of cogging torque, and to present a novel, rapid, half magnet pole pair technique for forecasting and evaluating cogging torque. The technique uses the finite element method as well as Matlab research and development oriented software tools to reduce numerous computing jobs and simulation time. An example of a rotor-skewed structure used to reduce cogging torque of permanent magnet synchronous machines is evaluated and compared with a conventional analysis method for the same motor to verify the effectiveness of the proposed approach. The novel method is proved valuable and suitable for large-capacity machine design.
Self-commissioning of permanent magnet synchronous machine drives using hybrid approach
Basar, Mehmet Sertug
2014-01-01
Self-commissioning of permanent-magnet (PM) synchronous machines (PMSMs) is of prime importance in an industrial drive system because control performance and system stability depend heavily on the accurate machine parameter information. This article focuses on a combination of offline and online...... parameter estimation for a non-salient pole PMSM which eliminates the need for any prior knowledge on machine parameters. Stator resistance and inductance are first identified at standstill utilising fundamental and high-frequency excitation signals, respectively. A novel method has been developed...... and employed for inductance estimation. Then, stator resistance, inductance and PM flux are updated online using a recursive least-squares (RLS) algorithm. The proposed controllers are designed using MATLAB/Simulink® and implemented on d-Space® real-time system incorporating a commercially available PMSM drive....
Co-Simulation of an Inverter Fed Permanent Magnet Synchronous Machine
Kiss Gergely Máté
2014-10-01
Full Text Available Co-simulation is a method which makes it possible to study the electric machine and its drive at once, as one system. By taking into account the actual inverter voltage waveforms in a finite element model instead of using only the fundamental, we are able to study the electrical machine's behavior in more realistic scenario. The recent increase in the use of variable speed drives justifies the research on such simulation techniques. In this paper we present the co-simulation of an inverter fed permanent magnet synchronous machine. The modelling method employs an analytical variable speed drive model and a finite element electrical machine model. By linking the analytical variable speed drive model together with a finite element model the complex simulation model enables the investigation of the electrical machine during actual operation. The methods are coupled via the results. This means that output of the finite element model serves as an input to the analytical model, and the output of the analytical model provides the input of the finite element model for a different simulation, thus enabling the finite element simulation of an inverter fed machine. The resulting speed and torque characteristics from the analytical model and the finite element model show a good agreement. The experiences with the co-simulation technique encourage further research and effort to improve the method.
Sadowski, Nelson; Bastos, J.P. Assumpcao; Carlson, R. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Eletrica; Lajoie-Mazenc, M. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France). Lab. d`Eletrotechnique et d`Eletronique Industrielle
1995-12-31
The finite elements method is used in the analysis of electric machines giving special emphasis to the synchronous machine. The developed computational method enables the obtention of global information such as torch, electromotive force, inductance, among others. The methodology is presented 6 figs., 7 refs.
Chen, Zhe; Blaabjerg, Frede; Iov, Florin
2005-01-01
A direct phase model of synchronous machines implemented in MA TLAB/SIMULINK is presented. The effects of the machine saturation have been included. Simulation studies are performed under various conditions. It has been demonstrated that the MATLAB/SIMULINK is an effective tool to study the complex...
Chen, Zhe; Blaabjerg, Frede; Iov, Florin
2005-01-01
A direct phase model of synchronous machines implemented in MA TLAB/SIMULINK is presented. The effects of the machine saturation have been included. Simulation studies are performed under various conditions. It has been demonstrated that the MATLAB/SIMULINK is an effective tool to study the complex...
Design of a switched reluctance generator
Heese, T.; Pyrhoenen, J.
1996-12-31
This report presents the design of a low voltage switched reluctance generator for variable speed applications showing the design of its construction and commutation unit. For the realisation of the control system the control strategy is presented. The principle and the theory of switched reluctance generators are described in this context. Also an overview of existing generator technology for these applications is given. The results gained suggest that switched reluctance machines can also advantageously be used as generators if the generating operation is considered within the design process. Compared with the existing technology a higher output power and efficiency is reached over the whole speed range. (orig.)
Qi-huai CHEN; Qing-feng WANG; Tao WANG
2015-01-01
A hybrid power transmission system (HPTS) is a promising way to save energy in a hydraulic excavator and the electric machine is one of the key components of the system. In this paper, a design process for permanent-magnet synchronous machines (PMSMs) in a hybrid hydraulic excavator (HHE) is presented based on the analysis of the working conditions and requirements of an HHE. A parameterized design approach, which combines the analytical model and the 2D finite element method (FEM), is applied to the electric machine to improve the design efficiency and accuracy. The analytical model is employed to optimize the electric machine efficiency and obtain the stator dimension and flux density distribution. The rotor is designed with the FEM to satisfy the flux requirements obtained in stator design. The rotor configuration of the PMSM employs an interior magnet structure, thus resulting in some inverse saliency, which allows for much higher values in magnetic flux density. To reduce the rotor leakage, a disconnected type silicon steel block structure is adopted. To improve the air gap flux density distribution, the trapezoid permanent magnet (PM) and centrifugal rotor structure are applied to PMSM. Demagnetization and armature reactions are also taken into consideration and calculated by the FEM. A prototype of the newly designed electric machine has been fabri-cated and tested on the experimental platform. The analytical design results are validated by measurements.
Vazquez, C.
2006-12-19
The ACE2 project deals with the development of a kynetic energy storage (KES) system for power peak shaving in high speed railway substations. This KES system consists in a double power converter which drives a switched reluctance machine (SRM) along with a flywheel operating in a wide speed range. This document presents from a technical point of view the features of the controller of the power converters for the U and UMOTOR SRM prototypes of that project. Hardware and software issues are treated in detail and the guide for the final user managing the KES module is introduced. (Author) 3 refs.
Kim, Seok-Kyoon; Song, Hwachang; Yoon, Tae-Woong
2015-04-01
On the basis of the non-linear third-order generator model, this article proposes a dual control scheme for a single synchronous machine equipped with an energy storage device to regulate the terminal voltage while enhancing the damping. Based on the input-output feedback linearisation method, the exciter controller is designed such that the terminal voltage robustly converges to its predetermined reference in the presence of a model uncertainty. In addition, the control input of the energy storage device feedbacks only the relative speed. It is shown that this controller can effectively increase the damping of the synchronous machine and that there is a set of initial conditions such that all trajectories started from this set go to the equilibrium point, satisfying input constraints. Moreover, it is also verified that all generator variables are bounded except for the power angle. The simulation results show that the closed-loop performance is satisfactory despite a transmission line fault and a model uncertainty in which the non-linear fourth-order generator model (two-axis) is used.
Applications and modelling of bulk HTSs in brushless ac machines
Barnes, G.J. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom). E-mail: gary.barnes at eng.ox.ac.uk; McCulloch, M.D.; Dew-Hughes, D. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom)
2000-06-01
The use of high temperature superconducting material in its bulk form for engineering applications is attractive due to the large power densities that can be achieved. In brushless electrical machines, there are essentially four properties that can be exploited; their hysteretic nature, their flux shielding properties, their ability to trap large flux densities and their ability to produce levitation. These properties translate to hysteresis machines, reluctance machines, trapped-field synchronous machines and linear motors respectively. Each one of these machines is addressed separately and computer simulations that reveal the current and field distributions within the machines are used to explain their operation. (author)
Applications and modelling of bulk HTSs in brushless ac machines
Barnes, G. J.; McCulloch, M. D.; Dew-Hughes, D.
2000-06-01
The use of high temperature superconducting material in its bulk form for engineering applications is attractive due to the large power densities that can be achieved. In brushless electrical machines, there are essentially four properties that can be exploited; their hysteretic nature, their flux shielding properties, their ability to trap large flux densities and their ability to produce levitation. These properties translate to hysteresis machines, reluctance machines, trapped-field synchronous machines and linear motors respectively. Each one of these machines is addressed separately and computer simulations that reveal the current and field distributions within the machines are used to explain their operation.
CAMPEANU, A.
2012-02-01
Full Text Available In the paper is shown that, by using the circuit theory which operates with lumped parameters, it is possible to derive mathematical models of a high power salient pole synchronous machine (SPSM, that can take into account the basic processes of the machine. It offers results regarding the electromagnetic and mechanical stresses for a given practical application. The quantitative determinations were performed on an 8000 kW synchronous motor. The results of quantitative determinations are of essential interest in the designing stage, for dynamic characteristics and parameters derivation and for constructive solutions to be chosen.
Design, analysis and fabrication of a linear permanent magnet synchronous machine
MONOJIT SEAL; MAINAK SENGUPTA
2017-08-01
This paper deals with the design, analysis and fabrication of a 320 W, 5 m/s, 4-pole permanentmagnet-based linear synchronous machine (LPMSM). The design deals with conventional hand calculations followed by design fine-tuning and analysis using standard FEM packages. Fabrication of the machine has beenalso done at the works of a local small machine manufacturer after procurement of imported permanent magnets (PMs). The work presented here focuses on design and fabrication of LPMSM linor stampings with fixed dimensions and standard available PM tablets with a view to providing simple design guidelines. This prototype forms part of a variable speed linear motor drive that is being developed. The approach presented here might provide new ideas to those researchers who may not have the capability to bear cost of fabrication of lamination and PMs from scratch but would like to manufacture LPMSMs from available stampings and tablet PMs.Additionally, it may serve as a base document for the R&D personnel in this area.
Cheng-zhi FAN; Ming-xing HUANG; Yun-yue YE
2009-01-01
We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the wave0form of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in direct-drive pumping units. We have installed and tested a directdrive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 6 1. 1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.
张芊; 胡猛; 李元栋
2012-01-01
The components of switched reluctance driver system are described in this essay. The SRD system hardware is required under the anchor machine conditions. Control strategies at differents stages of the system are described according to the anchor machine working requirements. The application of STD in marine anchor machine control system can achieve automotive control of anchor machine, so that ship electrical automation, ship intelligence, information level are raised to some extent.%介绍了开关磁阻电机调速系统（SRD）的基本组成。根据锚机工作条件提出SRD系统硬件要求，针对锚机工况要求阐述了在不同阶段系统的控制策略。将SRD用于船用锚机控制系统有助于实现锚机的自动控制，并在一定程度上提升了船舶电气自动化、智能化和信息化水平。
A.M. Galynovskiy
2013-10-01
Full Text Available Designing features for valve-engine transducers of brushless synchronous and asynchronized machines are described. Global analysis of research results on the transducer models in a MicroCap circuit simulation system is made, recommendations on the simulation system application in both scientific research and educational process given.
Lu, Kaiyuan; Vetuschi, M.; Rasmussen, Peter Omand;
2010-01-01
This paper presents a reliable method for the experimental determination of high-frequency d- and q -axis inductances for surface-mounted permanent-magnet synchronous machines (SMPMSMs). Knowledge of the high-frequency d- and q-axis inductances plays an important role in the efficient design...
赵铮; 刘慧娟; 张千
2011-01-01
利用有限元分析软件,对径向叠片磁阻转子的新型无刷双馈电机进行电磁场分析,计算了电机在额定功率下同步运行状态的铁心损耗和绕组损耗,并以此为依据分析了该电机的温度场.为这种新型无刷双馈电机的工程应用奠定了基础,为该电机的设计优化提供了理论指导.%This paper afforded a brushless doubly fed machine (BDFM) with radial reluctance rotor structure.Using finite element calculation software, set up the 2D model and analyzed the electromagnetic field.The coreloss and winding loss was calculated at rated power and synchronization operation.Based on the loss data, the temperature field was plot.All the result are investigated to prove its good significance of application and provide the guide for its future optimal design.
Javier Muñoz Álvarez
2011-02-01
Full Text Available Se presentan los fundamentos teóricos que modelan el comportamiento de los motores de reluctancia conmutaday sus accionamientos. Se exponen las características constructivas generales, las ecuaciones diferencialesque constituyen el modelo matemático del motor y se describen los bloques en Simulink utilizados para lasimulación. El sistema modular se valida comparando el comportamiento de las variables de salida con señalesobtenidas experimentalmente. Es empleado, además, para realizar diversos estudios sobre la instalación. Losresultados obtenidos en cada corrida son reflejados y se exponen las condiciones de operación y la explicaciónteórica de lo obtenido. This paper presents the theoretical basis that models the behavior of The switched reluctance machines andtheir drives. The general characteristics, the differential equation system that constitutes the mathematicalmodel of the motor and the Simulink's blocks, which have been built for running the simulation, are outlined. Theresults of the simulation have been shown and compared with those obtained experimentally. The Simulinkmodel is used for studying the Switched Reluctance motor drive behavior under some operation conditions andtheoretical explanations for the simulation's results are given in every case.
CHEN Yiguang; PAN Wei; SHEN Yonghuan; TANG Renyuan
2006-01-01
Conventional permanent magnet synchronous machine(PMSM)has the problem of large stator copper loss and narrow speed range. To solve this problem, an interior composite-rotor controllable-flux PMSM adaptive to multi-polar is proposed. This machine has the characteristics of low stator copper loss and wide-speed operation. The half-radial-set and half-tangential-set permanent magnets(PMs)are NdFeB that has high remanent flux density and high coercive force. The tangential-set PMs are AlNiCo that has high remanent flux density and low coercive force. By applying the pulse of d-axis stator current id, the magnetized intensity and direction of AlNiCo can be controlled. The flux created by NdFeB is repelled to stator and air-gap PM-flux is intensified, or is partially bypassed by AlNiCo in the rotor, so the air-gap PM-flux is weakened. The internal magnetic field distribution in two ultra magnetized situations is analyzed by finite element method. The dimension of PMs and magnetic structure are demonstrated. Especially when the q-axis magnetic resistance is larger and the q-axis inductance is smaller, the result of flux-weakening is better and the influence of armature reaction on air-gap PM-flux is weakened.
Elizondo, Marcelo A.; Tuffner, Francis K.; Schneider, Kevin P.
2016-01-01
Unlike transmission systems, distribution feeders in North America operate under unbalanced conditions at all times, and generally have a single strong voltage source. When a distribution feeder is connected to a strong substation source, the system is dynamically very stable, even for large transients. However if a distribution feeder, or part of the feeder, is separated from the substation and begins to operate as an islanded microgrid, transient dynamics become more of an issue. To assess the impact of transient dynamics at the distribution level, it is not appropriate to use traditional transmission solvers, which generally assume transposed lines and balanced loads. Full electromagnetic solvers capture a high level of detail, but it is difficult to model large systems because of the required detail. This paper proposes an electromechanical transient model of synchronous machine for distribution-level modeling and microgrids. This approach includes not only the machine model, but also its interface with an unbalanced network solver, and a powerflow method to solve unbalanced conditions without a strong reference bus. The presented method is validated against a full electromagnetic transient simulation.
Investigation of fault modes in permanent magnet synchronous machines for traction applications
Choi, Gilsu
Over the past few decades, electric motor drives have been more widely adopted to power the transportation sector to reduce our dependence on foreign oil and carbon emissions. Permanent magnet synchronous machines (PMSMs) are popular in many applications in the aerospace and automotive industries that require high power density and high efficiency. However, the presence of magnets that cannot be turned off in the event of a fault has always been an issue that hinders adoption of PMSMs in these demanding applications. This work investigates the design and analysis of PMSMs for automotive traction applications with particular emphasis on fault-mode operation caused by faults appearing at the terminals of the machine. New models and analytical techniques are introduced for evaluating the steady-state and dynamic response of PMSM drives to various fault conditions. Attention is focused on modeling the PMSM drive including nonlinear magnetic behavior under several different fault conditions, evaluating the risks of irreversible demagnetization caused by the large fault currents, as well as developing fault mitigation techniques in terms of both the fault currents and demagnetization risks. Of the major classes of machine terminal faults that can occur in PMSMs, short-circuit (SC) faults produce much more dangerous fault currents than open-circuit faults. The impact of different PMSM topologies and parameters on their responses to symmetrical and asymmetrical short-circuit (SSC & ASC) faults has been investigated. A detailed investigation on both the SSC and ASC faults is presented including both closed-form and numerical analysis. The demagnetization characteristics caused by high fault-mode stator currents (i.e., armature reaction) for different types of PMSMs are investigated. A thorough analysis and comparison of the relative demagnetization vulnerability for different types of PMSMs is presented. This analysis includes design guidelines and recommendations for
张婷婷; 曹莉; 刁小燕; 朱熀秋
2012-01-01
在阐述二自由度无轴承同步磁阻电机和三自由度混合磁轴承工作原理基础上,推导出五自由度无轴承同步磁阻电机状态方程,采用逆系统方法将五自由度无轴承同步磁阻电机这一非线性、强耦合的多输入多输出系统解耦并线性化为伪线性系统,并应用线性系统理论设计闭环控制器,最后采用Matlab软件环境构建了仿真系统,对转子起浮特性及解耦性能进行了仿真。仿真结果表明：这种解耦控制策略能够实现五自由度无轴承同步磁阻电机各个被控量之间的动态解耦,并且系统具有良好的动、静态性能。%Based on explanation of the operation principle for the 2 degrees of freedom（2-DOF） bearingless synchronous reluctance（BSRM） and 3-DOF magnetic bearing,the state equations of 5-DOF BSRM were deduced.As a multi-variable,nonlinear and strong-coupled system,the 5 degrees of freedom（5-DOF） bearingless synchronous reluctance motor（BSRM） was decoupled into pseudo-linear system using inverse system method.The linear system theory was proposed to design the closed-loop controllers.The simulation system was constructed by using Matlab software,and suspension characteristic of rotor and decoupling performance were simulated.The simulation results show that this kind of control strategy can realize dynamic decoupling among the controlled variables of the 5-DOF BSRM,and the control system has good dynamic and static performance.
High output power reluctance electric motors with bulk high-temperature superconductor elements
Kovalev, L. K.; Ilushin, K. V.; Penkin, V. T.; Kovalev, K. L.; Larionoff, A. E.; M-A Koneev, S.; Modestov, K. A.; Larionoff, S. A.; Poltavets, V. N.; Akimov, I. I.; Alexandrov, V. V.; Gawalek, W.; Oswald, B.; Krabbes, G.
2002-05-01
We present new types of electric machines with the rotors containing bulk high-temperature superconductor (HTS) - YBCO and Bi-Ag - elements. We discuss different schematics of hysteresis, reluctance, 'trapped field' and composed synchronous HTS machines. The two-dimensional mathematical models describing the processes in such types of HTS machines were developed on the basis of the theoretical analysis of the electrodynamic and hysteresis processes in the single-domain and polycrystal YBCO ceramic samples and plate shape Bi-Ag elements. We give the test results of the series of hysteresis, reluctance, 'trapped field' and composed with permanent magnets HTS motors with an output power rating of 0.1-18 kW and current frequencies 50 Hz and 400 Hz. These results show that in the media of liquid nitrogen the specific output power per one unit weight of the HTS motor is four to seven times better than for conventional electric machines. A comparison of the theoretical and experimental characteristics of the developed HTS motors show that they are in good agreement. We discuss the test results for a liquid nitrogen cryogenic pump system with a hysteresis 500 W HTS motor. We describe several designs of new HTS motors operating in the media of liquid nitrogen with an output power 125 kW (and more) and a power factor of more than 0.8. We discuss future applications of new types of HTS motors for aerospace technology, on-land industry and transport systems.
Efficiency Characteristics of Low Power Hybrid Switched Reluctance Motor
Jakobsen, Uffe; Ahn, Jin-Woo
2009-01-01
Switched reluctance motors (SRM) are usually considered inferior in terms of efficiency as compared to permanent magnet synchronous motors (PMSM) and brushless DC-motors (BLDC), but less costly. This article presents a test of a 70W hybrid switched reluctance motor (HSRM), that archieves a peak...... efficiency for the motor drive of more than 74%, and an efficiency for the motor of almost 80%....
D. Ouamara
2016-09-01
Full Text Available Authors compare the electromagnetic performances of three multi-phases permanent-magnet (PM synchronous machines (PMSM for Mild Hybridtraction application. This comparison was made using two-dimensional (2-D numerical simulations in transient magnetic with eddy-current reaction field in the PMs. The best machine was determined using an energetic analysis (i.e., losses, torque and efficiency according specifications. In this study, the non-overlapping winding with double layer (i.e. all teeth wound type was used. The winding synthesis is based on the "Star of slots" method as well as the Fourier series decomposition of the magnetomotive force (MMF.
Boudana, Djamel; Nezli, Lazhari; Tlemçani, Abdelhalim; Mahmoudi, Mohand Oulhadj; Tadjine, Mohamed
2012-05-01
The double star synchronous machine (DSSM) is widely used for high power traction drives. It possesses several advantages over the conventional three phase machine. To reduce the torque ripple the DSSM are supplied with source voltage inverter (VSI). The model of the system DSSM-VSI is high order, multivariable and nonlinear. Further, big harmonic currents are generated. The aim of this paper is to develop a new direct torque adaptive fuzzy logic control in order to control DSSM and minimize the harmonics currents. Simulations results are given to show the effectiveness of our approach.
Picot, Antoine; Obeid, Ziad; Régnier, Jérémi; Poignant, Sylvain; Darnis, Olivier; Maussion, Pascal
2014-01-01
International audience; In this paper, an original method for bearing fault detection in high speed synchronous machines is presented. This method is based on the statistical process of Welch's periodogram of the stator currents in order to obtain stable and normalized fault indicators. The principle of the method is to statistically compare the current spectrum to a healthy reference so as to quantify the changes over the time. A statistic-based indicator is then constructed by monitoring sp...
Fusco, Miguel A.V.; Reis, Luiz O.M. dos [Universidade de Taubate (UNITAU), SP (Brazil)
2009-07-01
In the printing industry there is several segments and one of these segments is the printing in sheet metal, known how cans manufacturer (metallography). This segment consists in a preparation of the steel plates for the manufacturing industry for both cans household and industrial fields. Today most of the machines in this market segment is old and often driven by only one electric motor. The speed variation occurs through electromechanical and / or electromagnetic inverters or DC motors whose process timing and positioning of the sheet along the machine is via mechanical systems gears, gearboxes, belts and transmissions. The objective of this work is to suggest the replacement of the set of mechanical transmission by a completely electronic system through the use of AC motors, frequency inverters and programmable logic controller (PLC), that the synchronization system and position are done by encoders coupled to the PLC, ensuring the proper functioning of the whole machine. Using this system, the index of maintenance will be reduced and the machine speed will be increased from 5% to 10%, ensuring a higher production.
张婷婷; 朱熀秋
2011-01-01
为了有效解决无轴承同步磁阻电机这一非线性、强耦合的多输入多输出系统的动态解耦问题,提出了基于α阶逆系统理论的无轴承同步磁阻电机解耦控制策略.本文在阐述了无轴承同步磁阻电机径向悬浮力产生机理的基础上,推导出其数学模型,采用α阶逆系统方法将原系统解耦并线性化为一个一阶线件积分子系统和两个二阶线性积分子系统,并应用线性系统理论设计了闭环控制器.最后采用MATLAB软件环境构建了仿真系统,针对系统的阶跃响应、转子起浮、解耦性能等进行了仿真和分析.仿真试验表明这种解耦控制策略能够实现无轴承同步磁阻电机电磁转矩与径向悬浮力之间的动态解耦.并且系统具有良好的动、静态性能.%A deeoupling control approach based on α-th order inverse system method has been developed for a bearingless synchronous reluctance motor(BSRM), which is a nonlinear, strong-coupled, multiple-input and multiple-output system. The working principle of radial suspension forces for the BSRM is explained and the mathematical models are derived in detail. Using α-order inverse system method, the original system is decoupled into one first-order linear integral subsystem and two second-order linear integral subsystems. The linear system theory is applied to design the closed-loop controllers. Simulation and analysis have been carried out for investigating the step response, rotor suspending forces,decoupling control, etc. Results validate the dynamic decoupling control among the electromagnetic torque and two radial suspension forces with desirable dynamic and static performances.
Percy Rafael Viego Felipe
2015-04-01
Full Text Available Se presenta un estudio sobre aplicaciones de los motores sincrónicos de reluctancia (MSR controlados por accionamientos de frecuencia variable (AFV, que posibilitan el ahorro de energía. Se realizó una comparación entre las características constructivas de los MSR y los motores asincrónicos de jaula (MA, evaluando las ventajas y limitaciones que aquellos presentan. Una ventaja notable del MSR es que las pérdidas en el rotor se eliminan prácticamente. Una comparación experimental evidenció que para igual momento, el MSR presenta una mayor eficiencia; y que para igual incremento de temperatura, con las mismas dimensiones IEC, se logra más potencia. Por comparaciones entre datos de un fabricante, se demostró las ventajas de utilizar, con el mismo AFV y para cargas centrífugas, un MSR de mayor clase de eficiencia que la de un MA. Un análisis económico con técnicas de descuento, evidenció una atractiva recuperación de la inversión cuando se opera todo el año. A study on applications of synchronous reluctance motor (SynRM controlled by variable frequency drives (VFD for energy saving is presented. A comparison between the basic construction elements of the SynRM and the squirrel cage induction motor (IM is carried out, evaluating advantages and disadvantages. A nearly complete elimination of rotor losses is a significant asset of the SynRM. An experimental comparison showed that at the same torque, the SynRM presents a higher efficiency than the IM; and that at the same temperature rise, more power is obtained with the same IEC frame for both motor types. Comparing data from a manufacturer, the advantages of using, with the same VFD and for centrifugal loads, a higher efficiency class SynRM than that of a lower efficiency IM was demonstrated. An economical study using discount techniques, made evident an attractive pay back when operating all year around.
Jeeng Min Ling
2016-08-01
Full Text Available The cogging torque in an inset permanent magnet synchronous machine causes some undesirable vibration and noises which should be reduced in the earliest possible stage of design. The influences of edge slotting and slot opening width in the magnet rotor pole on the cogging torque were investigated in this article. The structure of the proposed inset permanent magnet synchronous machine has 8 poles and 24 stator slots with fixed slot opening width and a modified magnet pole in the rotor. The finite element method magnetics (FEMM 4.2 tool was used to investigate the core saturation induced in the stator and rotor of the inset permanent magnet synchronous machine. The simulation results show that the slotting design in the magnet edge can effectively reduce the cogging torque of the inset permanent magnet synchronous machine.
Jeeng Min Ling; Tajuddin Nur
2016-01-01
The cogging torque in an inset permanent magnet synchronous machine causes some undesirable vibration and noises which should be reduced in the earliest possible stage of design. The influences of edge slotting and slot opening width in the magnet rotor pole on the cogging torque were investigated in this article. The structure of the proposed inset permanent magnet synchronous machine has 8 poles and 24 stator slots with fixed slot opening width and a modified magnet pole in the rotor. The f...
Maria Zaskalicka
2008-01-01
Full Text Available Reluctance stepper motors are becoming to be very attractive transducer to conversion of electric signal to the mechanical position. Due to its simple construction is reluctance machine considered a very reliable machine which not requiring any maintenance. Present paper proposes a mathematical method of an analytical calculus of a phase current and electromagnetic torque of the motor via Fourier series. Saturation effect and winding reluctance are neglected.
Electrical machines and assemblies including a yokeless stator with modular lamination stacks
Qu, Ronghai; Jansen, Patrick Lee; Bagepalli, Bharat Sampathkumar; Carl, Jr., Ralph James; Gadre, Aniruddha Dattatraya; Lopez, Fulton Jose
2010-04-06
An electrical machine includes a rotor with an inner rotor portion and an outer rotor portion, and a double-sided yokeless stator. The yokeless stator includes modular lamination stacks and is configured for radial magnetic flux flow. The double-sided yokeless stator is concentrically disposed between the inner rotor portion and the outer rotor portion of the electrical machine. Examples of particularly useful embodiments for the electrical machine include wind turbine generators, ship propulsion motors, switch reluctance machines and double-sided synchronous machines.
Rasilo, Paavo; Abdallh, Ahmed Abou-Elyazied; Belahcen, Anouar; Arkkio, Antero; Dupre, Luc
2015-01-01
The magnetic material characteristics of a wound-ﬁeld synchronous machine are identiﬁed based on global calorimetric core-loss and no-load curve measurements. This is accomplished by solving a coupled experimental-numerical electromagnetic inverse problem, formulated to minimize the difference between a ﬁnite-element (FE) simulation-based Kriging surrogate model and the measurement results. The core-loss estimation in the FE model is based on combining a dynamic iron-loss model and a static v...
Zhiyi Song
2012-01-01
Full Text Available The compound-structure permanent-magnet synchronous machine (CS-PMSM, comprising a double rotor machine (DRM and a permanent-magnet (PM motor, is a promising electronic-continuously variable transmission (e-CVT concept for hybrid electric vehicles (HEVs. By CS-PMSM, independent speed and torque control of the vehicle engine is realized without a planetary gear unit. However, the slip rings and brushes of the conventional CS-PMSM are considered a major drawback for vehicle application. In this paper, a brushless flux-modulated CS-PMSM is investigated. The operating principle and basic working modes of the CS-PMSM are discussed. Mathematical models of the CS-PMSM system are given, and joint control of the two integrated machines is proposed. As one rotor of the DRM is mechanically connected with the rotor of the PM motor, special rotor position detection and torque allocation methods are required. Simulation is carried out by Matlab/Simulink, and the feasibility of the control system is proven. Considering the complexity of the controller, a single digital signal processor (DSP is used to perform the interconnected control of dual machines instead of two separate ones, and a typical hardware implementation is proposed.
Kai-Hui Zhao
2017-06-01
Full Text Available To improve the accuracy of torque control for vector control of interior permanent-magnet synchronous machine (IPMSM, this study proposes a torque-sensorless control method based on cascaded sliding mode observer (SMO. First, the active flux model is discussed, which converts the model of IPMSM into the equivalent model of surface-mounted permanent-magnet synchronous machine. Second, to reduce chattering caused by system parameters variations and external disturbances, the cascaded observer is designed, which is composed of a variable gain adaptive SMO and an active flux SMO. The variable gain adaptive SMO is designed to estimate the speed, rotor position and stator resistance in the d–q reference frame. The active flux SMO is designed to estimate the active flux and torque in the α–β reference frame. Global asymptotic stability of the observers is guaranteed by the Lyapunov stability analysis. Finally, simulations and experiments are carried out to verify the effectiveness of the proposed control scheme.
A sensorless initial rotor position's estimation for permanent magnet synchronous machines
Krasnov, I.; Langraf, S.; Odnolopylov, I.; Koltun, V.
2015-10-01
Permanent magnet synchronous motors for the effective start require information about the initial position of a rotor. In this regard, most systems use position sensors, which substantially increase entirely a cost of an electrical drive [1-3]. The aim of this article is to develop a new method, allowing determining the absolute angular position of the permanent magnet synchronous motors’ rotor [4,5]. With a certain voltage pulses applied to the motor, its stator is magnetized by currents leakage in the windings. This allows using a special algorithm to calculate the absolute position of the rotor without using any motor parameters [6]. Simulation results prove the simplicity and efficiency of this method for determining an initial position of the permanent magnet synchronous motors’ rotor. Thus, this method can be widely used in the electrical industry.
380 kW synchronous machine with HTS rotor windings--development at Siemens and first test results
Nick, W.; Nerowski, G.; Neumüller, H.-W.; Frank, M.; van Hasselt, P.; Frauenhofer, J.; Steinmeyer, F.
2002-08-01
Applying HTS conductors in the rotor of synchronous machines allows the design of future motors or generators that are lighter, more compact and feature an improved coefficient of performance. To address these goals a project collaboration was installed within Siemens, including Automation & Drives, Large Drives as a leading supplier of electrical machines, Corporate Technology as a competence center for superconducting technology, and other partners. The main task of the project was to demonstrate the feasibility of basic concepts. The rotor was built from racetrack coils of Bi-2223 HTS tape conductor, these were assembled on a core and fixed by a bandage of glass-fibre composite. Rotor coil cooling is performed by thermal conduction, one end of the motor shaft is hollow to give access for the cooling system. Two cooling systems were designed and operated successfully: firstly an open circuit using cold gaseous helium from a storage vessel, but also a closed circuit system based on a cryogenerator. To take advantage of the increased rotor induction levels the stator winding was designed as an air gap winding. This was manufactured and fitted in a standard motor housing. After assembling of the whole system in a test facility with a DC machine load experiments have been started to prove the validity of our design, including operation with both cooling systems and driving the stator from the grid as well as by a power inverter.
Jingang Bai
2014-03-01
Full Text Available The compound-structure permanent-magnet synchronous machine (CS-PMSM is a power-split device which can enable the internal combustion engine (ICE to operate at optimum efficiency during all driving conditions by controlling its torque and speed. However, the CS-PMSM has more serious temperature rise and heat dissipation problems than conventional permanent-magnet (PM machines, especially when the CS-PMSM is running at low speed and under full load conditions. As the thermal resistance of double-layer air gaps is quite big, the hot spot proves to be in the inner winding rotor. To ensure the safe operation of the CS-PMSM, the use of forced-air and water cooling in the inner winding rotor are investigated. The study shows that the water cooling can provide a better cooling effect, but require a complicated mechanical structure. Considering the complexity of the high efficiency cooling system, a real-time temperature monitoring method is proposed and a temperature measuring system which can accurately measure the real-time temperature of multiple key points in the machine is developed to promptly adjust the operating and cooling conditions based on the measured temperature results. Finally, the temperature rise experiment of the CS-PMSM prototype is done and the simulation results are partly validated by the experimental data.
Spargo, C.M.; Mecrow, B.C.; Widmer, J.D.
2014-01-01
A novel method to calculate the harmonic torque components in synchronous machines is presented. Harmonic torque components create a torque ripple, which is undesirable in many applications. This torque ripple is a major cause of acoustic noise and vibration and can limit the machine's application range. A seminumerical method is developed to calculate and analyze harmonic torque components based on Maxwell stress tensor theory. Development of the Maxwell stress expressions leads to a simple ...
Synchronized assembly of gold nanoparticles driven by a dynamic DNA-fueled molecular machine.
Song, Tingjie; Liang, Haojun
2012-07-04
A strategy for gold nanoparticle (AuNP) assembly driven by a dynamic DNA-fueled molecular machine is revealed here. In this machine, the aggregation of DNA-functionalized AuNPs is regulated by a series of toehold-mediated strand displacement reactions of DNA. The aggregation rate of the AuNPs can be regulated by controlling the amount of oligonucleotide catalyst. The versatility of the dynamic DNA-fueled molecular machine in the construction of two-component "OR" and "AND" logic gates has been demonstrated. This newly established strategy may find broad potential applications in terms of building up an "interface" that allows the combination of the strand displacement-based characteristic of DNA with the distinct assembly properties of inorganic nanoparticles, ultimately leading to the fabrication of a wide range of complex multicomponent devices and architectures.
FEM analysis of an single stator dual PM rotors axial synchronous machine
Tutelea, L. N.; Deaconu, S. I.; Popa, G. N.
2017-01-01
The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors. The proposed topologies, the magneto-motive force analysis and quasi 3D-FEM analysis are the core of the paper.
Jiang, Ming
As an energy storage device, the flywheel has significant advantages over conventional chemical batteries, including higher energy density, higher efficiency, longer life time, and less pollution to the environment. An effective flywheel system can be attributed to its good motor/generator (M/G) design. This thesis describes the research work on the design of a permanent magnet synchronous machine (PMSM) as an M/G suitable for integration in a flywheel energy storage system within a large hybrid electric vehicle (HEV). The operating requirements of the application include wide power and speed ranges combined with high total system efficiency. Along with presenting the design, essential issues related to PMSM design including cogging torque, iron losses and total harmonic distortion (THD) are investigated. An iterative approach combining lumped parameter analysis with 2D Finite Element Analysis (FEA) was used, and the final design is presented showing excellent performance.
Haipeng Wang
2012-09-01
Full Text Available This paper deals with a fault-tolerant semi-12-phase permanent-magnet synchronous machine (PMSM used for electric vehicles. High fault-tolerant and low toque ripple features are achieved by employing fractional slot concentrated windings (FSCWs and open windings. Excessive magnetomotive force (MMF harmonic components can lead to thermal demagnetization of rotor magnets as well as high core loss. An improved all-teeth-wound winding disposition that changes the winding factor of each harmonic is applied to suppress harmonics. A relatively large slot leakage inductance that limits the short-circuit current (SCC induced in the short-circuited winding is proposed to deal with short-circuit fault. Fault-tolerant controls up to two phases open circuited are investigated in this paper based on keeping the same torque-producing MMF. The fault-tolerant control strategies corresponding to each faulty mode are studied and compared to ensure high performance operation.
Olfa B.H.B. Kechiche
2011-01-01
Full Text Available Problem statement: This study investigates a novel optimized scheme of a High Frequency Signal Injection (HFSI based sensorless technique in order to carry out a precise and robust rotor position error estimation of a Permanent Magnet Synchronous Motor (PMSM drive designed for washing machines. The study is carried out for standstill condition, where precise position information is required for this application. Approach: In order to get rotor position error information, a PMSM high frequency model is considered in the estimated rotor reference frame (d,q. Then, the impact of the HFSI technique parameters choice on the PMSM rotor position estimation performance is studied and experimentally tested, under various injection conditions. Results: The experimental results show that the amplitude of the high frequency current, resulting from injection, is not significant to carry out high performance rotor position estimation. In order to improve rotor position estimation performance and robustness, a modified demodulation of the high frequency current resulting from injection is proposed by using a high pass filter amplifier applied to PMSM measured currents. The novel proposed rotor position error extraction scheme is implemented on a dsPIC30F6010A and is experimentally validated on a 1kW washing salient pole PMSM. Conclusion: This study presents an improved high frequency voltage injection based sensorless control for Permanent Magnet Synchronous Motor (PMSM designed for washing machines. The optimal parameters choice of the HFSI technique and the use of a high pass filter amplifier have allowed to take the most of the high frequency injected signal for extracting the rotor position error at standstill, compared to a conventional scheme.
Sizov, Gennadi Y.
In this dissertation, a model-based multi-objective optimal design of permanent magnet ac machines, supplied by sine-wave current regulated drives, is developed and implemented. The design procedure uses an efficient electromagnetic finite element-based solver to accurately model nonlinear material properties and complex geometric shapes associated with magnetic circuit design. Application of an electromagnetic finite element-based solver allows for accurate computation of intricate performance parameters and characteristics. The first contribution of this dissertation is the development of a rapid computational method that allows accurate and efficient exploration of large multi-dimensional design spaces in search of optimum design(s). The computationally efficient finite element-based approach developed in this work provides a framework of tools that allow rapid analysis of synchronous electric machines operating under steady-state conditions. In the developed modeling approach, major steady-state performance parameters such as, winding flux linkages and voltages, average, cogging and ripple torques, stator core flux densities, core losses, efficiencies and saturated machine winding inductances, are calculated with minimum computational effort. In addition, the method includes means for rapid estimation of distributed stator forces and three-dimensional effects of stator and/or rotor skew on the performance of the machine. The second contribution of this dissertation is the development of the design synthesis and optimization method based on a differential evolution algorithm. The approach relies on the developed finite element-based modeling method for electromagnetic analysis and is able to tackle large-scale multi-objective design problems using modest computational resources. Overall, computational time savings of up to two orders of magnitude are achievable, when compared to current and prevalent state-of-the-art methods. These computational savings allow
Fedotov A.
2017-02-01
Full Text Available The article proposes a method of mathematical simulation of electrical machines with thyristor exciters on the basis of the local Fourier transform. The present research demonstrates that this method allows switching from a variable structure model to a constant structure model. Transition from the continuous variables to the discrete variables is used. The numerical example is given in the paper.
Fedotov, A.; Fedotov, E.; Bahteev, K.
2017-02-01
The article proposes a method of mathematical simulation of electrical machines with thyristor exciters on the basis of the local Fourier transform. The present research demonstrates that this method allows switching from a variable structure model to a constant structure model. Transition from the continuous variables to the discrete variables is used. The numerical example is given in the paper.
A Novel Cogging Torque Simulation Method for Permanent-Magnet Synchronous Machines
Chun-Yu Hsiao; Jonq-Chin Hwang; Sheng-Nian Yeh
2011-01-01
Cogging torque exists between rotor mounted permanent magnets and stator teeth due to magnetic attraction and this is an undesired phenomenon which produces output ripple, vibration and noise in machines. The purpose of this paper is to study the existence and effects of cogging torque, and to present a novel, rapid, half magnet pole pair technique for forecasting and evaluating cogging torque. The technique uses the finite element method as well as Matlab research and development oriented so...
Lascu, Christian; Boldea, Ion; Blaabjerg, Frede
2013-01-01
This paper investigates a permanent magnet synchronous motor drive controlled by a second-order variable structure control technique, known as the super-twisting sliding modes (STSM) control. The STSM controller is designed as a direct torque and flux controller and it works in the stator flux...... reference frame, rather than the rotor frame, as a regular vector control scheme. Another second-order sliding mode controller (SMC) was developed and compared with the STSM controller. Also for comparison, a similar direct torque control scheme based on linear PI controllers was developed and tested....... The tests show that the STSM controller displays very robust behavior, like any SMC, and it works without notable chattering, like the linear PI-based controller. The paper presents theoretical aspects for the STSM control, several design and implementation details, and comparative experimental results...
Discrete Optimal Multirate Techniques for Excitation Controller Design of a Synchronous Machine
D. I. Pappas
2016-02-01
Full Text Available An optimal control strategy based on Two-Point-Multirate Controllers (TPMRCs, is used to design a desirable excitation controller of a hydrogenerator system, in order to enhance its dynamic stability characteristics. In the TPMRCs based scheme, the control is constrained to a certain piecewise constant signal, while each of the controlled plant outputs is detected many times over a fundamental sampling period T0. On the basis on this strategy, the original problem is reduced to an associate discrete-time linear quadratic (LQ regulation problem for the performance index with cross product terms, for which a fictitious static state feedback controller is needed to be computed. Simulation results for the actual 117 MVA synchronous generator with conventional exciter supplying line to an infinite grid show the effectiveness of the proposed method which has a quite satisfactory performance.
Zdeněk NOVÁK
2013-12-01
Full Text Available The first part of this paper deals with the measuring of hysteresis loop of the toroidal shape core. LabVIEW software is used to automate this process. The results are compared with the data from the manufacturer and used in the FEMM software for setting parameters of the stator core of Permanent magnet synchronous motor (PMSM. Then, in the second part of this paper, the Lua scripting engine in FEMM software is used to optimize stator tooth width. Program code is written in the Matlab environment and after starting the run process, Matlab uses inter-process communication via ActiveX to connect with FEMM. In this process program tries several options for the stator tooth width. Based on the results, user can evaluate all the data about the overall progress and choose the optimal stator tooth width.
Torque ripple reduction in electric machines
Reddy, Patel Bhageerath; Huh, Kum-Kang; El-Refaie, Ayman Mohamed Fawzi; Galioto, Steven Joseph
2017-08-22
An electric machine, such as an Internal Permanent magnet or Synchronous Reluctance machine, having X phases, that includes a stator assembly, having M slots, with a stator core and stator teeth, that is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface that defines a cavity; and a rotor assembly, having N poles, disposed within the cavity which is configured to rotate about the longitudinal axis, wherein the rotor assembly includes a shaft, a rotor core located circumferentially around the shaft. The machine is configured such that a value k=M/(X*N) wherein k is a non-integer greater than about 1.3. The electric machine may alternatively, or additionally, include a non-uniformed gap between the exterior surface of the rotor spokes and the interior stator surface of the stator.
Mijatovic, Nenad; Jensen, Bogi Bech
2014-01-01
This paper presents experimental results from the Superwind laboratory setup. Particular focus in the paper has been placed on describing and quantifying the influence of armature reaction on performance of the HTS filed winding. Presented experimental results have confirmed the HTS field winding...... sensitivity to both armature reaction intensity and angular position with respect to the HTS coils. Furthermore, the characterization of the HTS field winding has been correlated to the electromagnetic torque of the machine where the maximal Ic reduction of 21% has been observed for the maximum torque....
Mijatovic, Nenad; Jensen, Bogi Bech
2014-05-01
This paper presents experimental results from the Superwind laboratory setup. Particular focus in the paper has been placed on describing and quantifying the influence of armature reaction on performance of the HTS filed winding. Presented experimental results have confirmed the HTS field winding sensitivity to both armature reaction intensity and angular position with respect to the HTS coils. Furthermore, the characterization of the HTS field winding has been correlated to the electromagnetic torque of the machine where the maximal Ic reduction of 21% has been observed for the maximum torque.
Wu, Zhihong; Lu, Ke; Zhu, Yuan
2015-01-01
The torque output accuracy of the IPMSM in electric vehicles using a state of the art MTPA strategy highly depends on the accuracy of machine parameters, thus, a torque estimation method is necessary for the safety of the vehicle. In this paper, a torque estimation method based on flux estimator with a modified low pass filter is presented. Moreover, by taking into account the non-ideal characteristic of the inverter, the torque estimation accuracy is improved significantly. The effectiveness of the proposed method is demonstrated through MATLAB/Simulink simulation and experiment.
Xie, Ge
parameters such as resistance and inductance are involved in many existing sensorless control algorithms. Therefore, varying machine parameters due to different operation conditions may affect the accuracy of the position estimation and the drive performance consequently. For power converter manufactures...... of the typical sensorless algorithm – the INFORM method is implemented and tested. It is demonstrated that the voltage error may seriously affect the performance of the position estimator. To overcome this difficulty, a new implementation scheme of the INFORM method with easy inverter voltage error compensation......) PWM periods. In the injection period, the voltage output from the inverter is forced to be zero. The rotor position and the speed are then estimated simply from the current changes during this zero voltage injection period. This method provides a good performance for the rotor position estimation...
Zhiyi Song
2012-10-01
Full Text Available The radial-radial flux compound-structure permanent-magnet synchronous machine (CS-PMSM, integrated by two concentrically arranged permanent-magnet electric machines, is an electromagnetic power-splitting device for hybrid electric vehicles (HEVs. As the two electric machines share a rotor as structural and magnetic common part, their magnetic paths are coupled, leading to possible mutual magnetic-field interference and complex control. In this paper, a design method to ensure magnetic decoupling with minimum yoke thickness of the common rotor is investigated. A prototype machine is designed based on the proposed method, and the feasibility of magnetic decoupling and independent control is validated by experimental tests of mutual influence. The CS-PMSM is tested by a designed driving cycle, and functions to act as starter motor, generator and to help the internal combustion engine (ICE operate at optimum efficiency are validated.
Yan, Liang; Li, Wei; Jiao, Zongxia; Chen, I.-Ming
2015-12-01
The space utilization of linear switched reluctance machine is relatively low, which unavoidably constrains the improvement of system output performance. The objective of this paper is to propose a novel tubular linear switched reluctance motor with double excitation windings. The employment of double excitation helps to increase the electromagnetic force of the system. Furthermore, the installation of windings on both stator and mover can make the structure more compact and increase the system force density. The design concept and operating principle are presented. Following that, the major structure parameters of the system are determined. Subsequently, electromagnetic force and reluctance are formulated analytically based on equivalent magnetic circuits, and the result is validated with numerical computation. Then, a research prototype is developed, and experiments are conducted on the system output performance. It shows that the proposed design of electric linear machine can achieve higher thrust force compared with conventional linear switched reluctance machines.
Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems
Weber, Luke G.
power. The scope of this work is to • develop a mathematical model for a salient pole, 2 damper winding synchronous generator with d axis saturation suitable for transient analysis, • develop a mathematical model for a voltage regulator and excitation system using the IEEE AC8B voltage regulator and excitation system template, • develop mathematical models for an energy storage primary control system, LC filter and transformer suitable for transient analysis, • combine the generator and energy storage models in a micro-grid context, • develop mathematical models for electric system components in the stationary abc frame and rotating dq reference frame, • develop a secondary control network for dispatch of micro-grid assets, • establish micro-grid limits of stable operation for step changes in load and power commands based on simulations of model data assuming net load on the micro-grid, and • use generator and electric system models to assess the generator current magnitude during phase-to-ground faults.
Fan, Yuchao; Hautier, J. P.
1994-01-01
This paper presents the remedial strategies for a converter-synchronous machine system, which would be used in case of conduction faults in the converter. After an analysis of the influence of transistor drive faults, in the conversion system characteristics, a remedial strategy in single-phase operation is proposed to palliate the consequences of the transistor faults when the neutral point of synchronous machine is not connected. Developed torque in this operating mode is pulsating. To eliminate this inconvenient which disturbs the speed regulation, an optimized remedial strategy in two-phase operation is then proposed. The power part is modified and the neutral point of synthronous machine is connected to DC voltage. Simulation and experimentation validate the proposed strategies. Cet article présente des marches dégradées optimisées applicables à un ensemble convertisseur-machine synchrone, lorsque des défauts de conduction apparaissent au niveau du convertisseur. Après analyse de l'influence d'un défaut de commande sur les caractéristiques de l'ensemble d'entraînement, une stratégie de rattrapage, en marche dégradée monophasée, est d'abord proposée pour pallier aux inconvénients de deux types de défauts lorsque le neutre de la machine est isolé. Dans ce mode de marche, le couple développé par la machine synchrone est pulsatoire. Afin d'éviter cet inconvénient, nous proposons, ensuite, une marche dégradée en mode biphasé par modification de la structure de puissance, en reliant le neutre de la machine au point milieu d'alimentation. Enfin, les stratégies de commande proposées sont validées par la simulation et l'expérience.
Shark - new motor design concept for energy saving-applied to Switched Reluctance Motor
Tataru, Ana Mari
The aim of this thesis is to document and promote a relatively new concept of designing electrical machine with improved efficiency, without using more or better material. The concept, called Shark, consists in replacing the cylindrical air gap by a non-linear shape obtained by translating specific...... of quick analysis tools, an analytical model of the Shark Switched Reluctance Machine is also proposed in this thesis. This model is conceived by modifying one of the existing models of cylindrical air gap Switched Reluctance Machines, such as to account for the presence of the Shark profiles in the air...
Prieto Rodriguez, Dany
2015-01-01
This thesis focuses on the study of a structure of permanent magnet electric motor which reduces the amount used of permanent magnets composed of rare earths and which can be used in industrial applications. In the first part of the research work, it is shown that the permanent magnet assisted synchronous reluctance machine is a good alternative. A parametric analyse is realised using a finite element modelling in order to highlight the peculiarities of its electromagnetic behaviour. Then, an...
Kouadio, L.
1996-12-12
A new method for spark-ignition engine control, more especially in idle conditions, has been developed to prevent engine stalling and improve its idling performances in terms of fuel consumption and pollutant emissions: the car synchronous machine, traditionally operating as an alternator, is used in certain phases to provide an external supplementary torque on the engine shaft. Methods are proposed for optimising the synchronous machine operation as a generator and as an engine, then the main engine control parameters are presented and a linear signal model is established around a nominal idling point, which is used for simulations. Experimental results show evident reductions of fuel consumption and a significant robustness improvement in the engine dynamics
Study on switched reluctance generator
潘再平; 金英; 张慧
2004-01-01
The linear and non-linear math models of the switched reluctance generator (SRG) in generator mode were established in this work. The phase current and energy conversion process during generator operation were simulated by the linear math model. The non-linear math model was used to analyze the characteristics of the SRG operation in self-excitation mode and in separately-excitation mode. Some important findings on how the SRG is operated and controlled were obtained in this study, which provides theoretical basis for further design and experimental study.
Fan, Yuchao; Hautier, J.
1994-01-01
Cet article présente des marches dégradées optimisées applicables à un ensemble convertisseur-machine synchrone, lorsque des défauts de conduction apparaissent au niveau du convertisseur. Après analyse de l'influence d'un défaut de commande sur les caractéristiques de l'ensemble d'entraînement, une stratégie de rattrapage, en marche dégradée monophasée, est d'abord proposée pour pallier aux inconvénients de deux types de défauts lorsque le neutre de la machine est isolé. Dans ce mode de march...
盾构机刀盘多电机同步驱动研究%Synchronously research of the shield machine cutter drive
赵刚; 刘德全
2012-01-01
盾构机／5盘由多个电机共同驱动，需要对多电机进行同步控制和负载平衡控制，即让电机速度相同的情况下，承担相应的平均负载。本文描述了多电机同步控制的几种方式，并对各种控制方式的特点进行了比较，同时介绍了中8780土压平衡盾构机刀盘驱动的实际应用。%The shield machine cutter is driven together by several motors. We need to carry on the synchronous and the load balance controls to many motors, then let the motor speed is same under average load. This text described a few methods that many motors synchronously control and compared the characteristics of various control method. At the same time introducing actual application of the q08780 Earth Press Balance shield machine cutter drive.
Energy Transformations in a Self-Excited Switched Reluctance Generator
Abelardo Martinez-Iturbe
2016-04-01
Full Text Available Wind generation systems require mechanisms that allow optimal adaptation of the generator to varying wind speed and to extract maximum energy from the wind. Robust and affordable high-performance methods are also needed for isolated sites. This paper takes this approach, in which an AC switched reluctance generator is used as a generator with a variable rotor speed. Although the voltage obtained is of insufficient quality to connect the generator directly to the power grid, this kind of generator can be used in isolated sites to charge a battery bank with a simple bridge rectifier. Due to the nonlinear behavior of the machine with the position and current, along with the alternating nature of the current that circulates through its phases, the machine experiences cyclical energy transformations of a mechanical, electrical and magnetic nature. This paper analyzes these transformations for the purpose of providing guidelines for machine design and optimization as a wind turbine in isolated sites.
Alireza Rasekh
2016-11-01
Full Text Available In this paper, a set of correlations for the windage power losses in a 4 kW axial flux permanent magnet synchronous machine (AFPMSM is presented. In order to have an efficient machine, it is necessary to optimize the total electromagnetic and mechanical losses. Therefore, fast equations are needed to estimate the windage power losses of the machine. The geometry consists of an open rotor–stator with sixteen magnets at the periphery of the rotor with an annular opening in the entire disk. Air can flow in a channel being formed between the magnets and in a small gap region between the magnets and the stator surface. To construct the correlations, computational fluid dynamics (CFD simulations through the frozen rotor (FR method are performed at the practical ranges of the geometrical parameters, namely the gap size distance, the rotational speed of the rotor, the magnet thickness and the magnet angle. Thereafter, two categories of formulations are defined to make the windage losses dimensionless based on whether the losses are mainly due to the viscous forces or the pressure forces. At the end, the correlations can be achieved via curve fittings from the numerical data. The results reveal that the pressure forces are responsible for the windage losses for the side surfaces in the air-channel, whereas for the surfaces facing the stator surface in the gap, the viscous forces mainly contribute to the windage losses. Additionally, the results of the parametric study demonstrate that the overall windage losses in the machine escalate with an increase in either the rotational Reynolds number or the magnet thickness ratio. By contrast, the windage losses decrease once the magnet angle ratio enlarges. Moreover, it can be concluded that the proposed correlations are very useful tools in the design and optimizations of this type of electrical machine.
LU Qiang; MEI ShengWei; ZHENG ShaoMing
2007-01-01
To verify the performance of NR-PSS (Nonlinear Robust Power System Stabilizer) for large synchronous generators, field experiments were carried out on a 300 MW generator in Baishan Hydro Plant of Northeast China Power Grid. The experiment results show that NR-PSS can improve the generator damping and enhance system stability remarkably.
The Role of Reluctance in PM Motors
Otaduy, P.J.
2005-06-16
The international research community has lately focused efforts on interior permanent magnet (IPM) motors to produce a traction motor for hybrid electric vehicles (HEV). One of the beneficial features of this technology is the additional torque produced by reluctance. The objective of this report is to analytically describe the role that reluctance plays in permanent magnet (PM) motors, to explore ways to increase reluctance torque without sacrificing the torque produced by the PMs, and to compare three IPM configurations with respect to torque, power, amount of magnet material required (cost), and percentage of reluctance torque. Results of this study will be used to determine future research directions in utilizing reluctance to obtain maximum torque and power while using a minimum amount of magnet material.
Shark, new motor design concept for energy saving applied to switched reluctance motor
Tataru Kjaer, A.M.
2005-07-01
The aim of this thesis is to document and promote a relatively new concept of designing electrical machine with improved efficiency, without using more or better material. The concept, called Shark, consists in replacing the cylindrical air gap by a non-linear shape obtained by translating specific geometrical pattern on the longitudinal axis of the electrical machine. This shape modification increases the air gap area and thus the energy conversion, taking place in the machine. Whilst other methods of improving the efficiency consider the use of more and/or better magnetic material and/or optimisation of the magnetic circuit of the radial cross-section of the machine, the proposed method makes use of the longitudinal cross-section of the machine. In spite of a few reports claiming the improvement of the efficiency by applying the optimisation of the longitudinal cross-section, none analysis of various air gap shapes and of their influence on the magnetic performance has been reported. Due to a simple geometry, the Switched Reluctance Machine has been selected for demonstration of the Shark principle. Initially, linear and finite element analyses are considered. They provide the basic knowledge of the manner in which various Shark air gap, having different dimensions, influence the energy conversion in the machine. The saturation mechanisms, specific to each Shark profile are analysed and optimum Shark profile and its dimensions are selected for implementation in a demonstration machine. Due to the lack of quick analysis tools, an analytical model of the Shark Switched Reluctance Machine is also proposed in this thesis. This model is conceived by modifying one of the existing models of cylindrical air gap Switched Reluctance Machines, such as to account for the presence of the Shark profiles in the air gap. The calculations are verified by measurement on two demonstration machines, having cylindrical and Shark air gaps. The measurement proved the theory right and
Silva, J.C.; Colvara, L.D. [Universidade Estadual Paulista (FEIS/UNESP), Ilha Solteira, SP (Brazil). Dept. de Engenharia Eletrica], Emails: jadiel_silva@hotmail.com, laurence@dee.feis.unesp.br
2009-07-01
The problem of stability of electric power systems, from the standpoint of ability to sync and how FACTS (Flexible Alternating Current Transmission Systems) devices affect this ability in particular the TSCS (Thyristor Controlled Series Compensator) inserted into an environment multi machine, is addressed. The effects of this device on the power synchronizing are considered through analysis of the matrix admittance of the bar, focusing on the transfer admittances between machines.
Gennari, Jorge L.; Vasconcellos, Alexandre S. de [Figener Engenheiros Associados (Brazil)
1996-07-01
Generators and synchronous motors may supply the necessary power factor correction, which tends to turn unnecessary the installation of capacitors. However, it is necessary to calculate how much more the company will pay in electric power bill when the stop of such machinery be necessary, either in a programed or emergency situation. Therefore, the decision of installing capacitors depends on this calculation. This work shows some criteria and results of a study case. 3 figs., 6 tabs.
ABDI, B.
2009-10-01
Full Text Available Electro-mechanical batteries have important advantages as compared with chemical batteries, especially in low earth orbit satellites applications. High speed slotless external rotor permanent magnet machines are used in these systems as Motor/Generator. Proper material and structure for space applications are introduced. A simplified analytic design method is given for this type of machines. Finally, the optimization of machine in order to have maximum efficiency and minimum volume and weight are given in this paper. Particle swarm optimization is used as the optimization algorithm and the finite element-based simulations are used to confirm the design and optimization process and show less than 1.2% error in parametric design.
Salvado, José; Espírito-Santo, António; Calado, Maria
2012-01-01
This paper proposes a distributed system for analysis and monitoring (DSAM) of vibrations and acoustic noise, which consists of an array of intelligent modules, sensor modules, communication bus and a host PC acting as data center. The main advantages of the DSAM are its modularity, scalability, and flexibility for use of different type of sensors/transducers, with analog or digital outputs, and for signals of different nature. Its final cost is also significantly lower than other available commercial solutions. The system is reconfigurable, can operate either with synchronous or asynchronous modes, with programmable sampling frequencies, 8-bit or 12-bit resolution and a memory buffer of 15 kbyte. It allows real-time data-acquisition for signals of different nature, in applications that require a large number of sensors, thus it is suited for monitoring of vibrations in Linear Switched Reluctance Actuators (LSRAs). The acquired data allows the full characterization of the LSRA in terms of its response to vibrations of structural origins, and the vibrations and acoustic noise emitted under normal operation. The DSAM can also be used for electrical machine condition monitoring, machine fault diagnosis, structural characterization and monitoring, among other applications. PMID:22969364
Maria Calado
2012-06-01
Full Text Available This paper proposes a distributed system for analysis and monitoring (DSAM of vibrations and acoustic noise, which consists of an array of intelligent modules, sensor modules, communication bus and a host PC acting as data center. The main advantages of the DSAM are its modularity, scalability, and flexibility for use of different type of sensors/transducers, with analog or digital outputs, and for signals of different nature. Its final cost is also significantly lower than other available commercial solutions. The system is reconfigurable, can operate either with synchronous or asynchronous modes, with programmable sampling frequencies, 8-bit or 12-bit resolution and a memory buffer of 15 kbyte. It allows real-time data-acquisition for signals of different nature, in applications that require a large number of sensors, thus it is suited for monitoring of vibrations in Linear Switched Reluctance Actuators (LSRAs. The acquired data allows the full characterization of the LSRA in terms of its response to vibrations of structural origins, and the vibrations and acoustic noise emitted under normal operation. The DSAM can also be used for electrical machine condition monitoring, machine fault diagnosis, structural characterization and monitoring, among other applications.
Salvado, José; Espírito-Santo, António; Calado, Maria
2012-01-01
This paper proposes a distributed system for analysis and monitoring (DSAM) of vibrations and acoustic noise, which consists of an array of intelligent modules, sensor modules, communication bus and a host PC acting as data center. The main advantages of the DSAM are its modularity, scalability, and flexibility for use of different type of sensors/transducers, with analog or digital outputs, and for signals of different nature. Its final cost is also significantly lower than other available commercial solutions. The system is reconfigurable, can operate either with synchronous or asynchronous modes, with programmable sampling frequencies, 8-bit or 12-bit resolution and a memory buffer of 15 kbyte. It allows real-time data-acquisition for signals of different nature, in applications that require a large number of sensors, thus it is suited for monitoring of vibrations in Linear Switched Reluctance Actuators (LSRAs). The acquired data allows the full characterization of the LSRA in terms of its response to vibrations of structural origins, and the vibrations and acoustic noise emitted under normal operation. The DSAM can also be used for electrical machine condition monitoring, machine fault diagnosis, structural characterization and monitoring, among other applications.
无刷同步电机的起动性能仿真%Simulation of Brushless Synchronous Machine's Starting Performance
李岩; 张超; 刘陵顺
2012-01-01
For the situation that the brushless synchronous machine used to run less in starting status, this paper designs a brushless synchronous motor's simulation model in start running state. The motor starting system as the study object of the model, the use of modular thinking, were established exciter, main generator, rotating rectifier and control units and other modules, the use of these modules and build a complete start-run model, and that the model simulation studies for the early start. Simulation results show that the model has some feasibility and validity, for further study the starting performance of brushless synchronous motor lay foundation.%针对目前国内无刷同步电机较少应用于电动运行的现状,设计一种无刷同步电机起动运行状态的仿真模型.该模型以电机起动系统为研究对象,利用模块化思路,分别建立励磁机、主发电机、旋转整流器以及控制单元等模块,运用这些模块搭建一个完整的起动运行模型,并对所建立的模型进行起动初期的仿真研究.仿真结果表明:该模型有一定的可行性和有效性,能为进一步研究无刷同步电机的起动性能奠定基础.
Inductance calculation of reluctance rotor brushless doubly-fed machine%凸极转子无刷双馈电机的电感参数计算及转子设计
龚晟; 杨向宇; 纪梁洲
2013-01-01
针对凸极无刷双馈电机两套定子绕组难于进行参数计算的问题,在传统的绕组函数法的基础上,应用分段函数来描述绕组函数以及反气隙函数,以此来计算有着两套绕组的无刷双馈电机定子功率和控制两套绕组的各自自感及互感,然后以此方法应用于转子形状的优化设计中,针对一系列极宽度不同的转子计算其自感和互感,并利用计算结果得到了最优的转子极宽度.通过与有限元数值计算方法所得到的计算结果进行对比,证明了提出方法的准确性,在计算转子极宽度最优值的应用中,体现了此方法的工程价值.%Given the difficulty of calculating parameters of two sets of stator winding of brushless doubly fed machine, this paper described the winding function and anti-gap function by using segment function in order to calculate the control and power winding of brushless doubly-fed machine based on traditional winding function method, and then got more accurate result. In comparison with the results from FEM method, the method in this paper proves to be accurate and its application value for engineering is dem onstrated in the calculation of the optimal width of rotor pole.
Mathematical Model of Linear Switched Reluctance Motor with Mutual Inductance Consideration
Nikolay Grebennikov
2015-06-01
Full Text Available This paper presents developing an mathematical model for linear switched reluctance motor (LSRM with account of the mutual inductance between the phases. Mutual interaction between the phases of LSRM gives the positive effect, as a rule the power of the machine is increased by 5-15%.
Knudsen, Hans
1995-01-01
in the stator. A consistent method is developed to determine model parameters from standard machine data. A phasor model of the line commutated converter is presented. The converter model includes not only the fundamental frequency, but also any chosen number of harmonics without a representation of the single...
Costa Bortoni, Edson da; Jardini, Jose Antonio [Sao Paulo Univ., SP (Brazil). Escola Politecnica
1995-12-31
This work presents the development of a equipment to be used for the determination of synchronous machines parameters though the frequency response method. The methodology is presented. A case study based on literature data is presented 9 figs., 2 tabs., 7 refs.
Belqorchi, Abdelghafour
Forty years after Watson and Manchur conducted the Stand-Still Frequency Response (SSFR) test on a large turbogenerator, the applicability of this technic on a powerful salient pole synchronous generator has yet to be confirmed. The scientific literature on the subject is rare and very few have attempted to compare SSFR parameter results with those deduced by classical tests. The validity of SSFR on large salient pole machines has still to be proven. The present work aims in participating to fill this knowledge gap. It can be used to build a database of measurements highly needed to draw the validity of the technic. Also, the author hopes to demonstrate the potential of SSFR model to represent the machine, not only in cases of weak disturbances but also strong ones such as instantaneous three-phase short-circuit faults. The difficulties raised by previous searchers are: The lack of accuracy in very low frequency measurements; The difficulty in rotor positioning, according to d and q axes, in case of salient pole machines; The measurement current level influence on magnetizing inductances, in axes-d and; The rotation impact on damper circuits for some rotors design. Aware of the above difficulties, the author conducted an SSFR test on a large salient pole machine (285 MVA). The generator under test has laminated non isolated rotor and an integral slot number. The damper windings in adjacent poles are connected together, via the polar core and the rotor rim. Finally, the damping circuit is unaffected by rotation. To improve the measurement accuracy, in very low frequencies, the most precise frequency response analyser available on the market was used. Besides, the frequency responses of the signals conditioning modules (i.e., isolation, amplification...) were accounted for to correct the four measured SSFR transfer functions. Immunization against noise and use of instrumentation in their optimum range, were other technics rigorously applied. Magnetizing inductances
Permanent Magnet Boosted Modular Switched Reluctance Motor
SZABÓ Loránd
2016-10-01
Full Text Available This paper deals with the analyses of a novel motor structure obtained by boosting with permanent magnets a formerly studied modular switched reluctance motor. Upon dynamic simulation results the improvements of the proposed motor are emphasized.
宋亚林
2015-01-01
This paper discusses the hydraulic open loop and closed loop system and its characteristics of synchronous control. The Application of hydraulic closed loop synchronization control system in hydraulic type three roller symmetrical bending machine was introduced in this paper.%论述了液压开环与闭环同步控制系统及其特点，并对液压闭环同步控制系统在液压式三辊对称卷板机中的应用进行了介绍。
Paulo S. G. Magalhães
2008-06-01
Full Text Available Um dos problemas encontrados na colheita mecanizada da cana-de-açúcar é a falta de sincronismo entre a colhedora e o transbordo, ocasionando perdas tanto de material como de capacidade operacional. A presente pesquisa teve como objetivo desenvolver um sistema capaz de auxiliar no sincronismo entre a colhedora e o veículo de transbordo por meio de comunicação sem fio. Dois sensores de ultra-som acoplados ao elevador e um microprocessador gerenciam tais informações, gerando correta sincronia entre as máquinas. O sistema foi testado em laboratório e em campo, cumprindo corretamente a função de manter as máquinas em sincronia, indicando e alertando aos operadores as suas posições relativas. O sistema desenvolvido reduziu as perdas de rebolo em cerca de 60 kg ha-1, comparado com a colheita realizada com o sistema desligado.One of the problems found in mechanical harvest of sugar cane is the lack of synchronism between the harvest machine and the infield wagon, causing crop losses as well as operational capacity. The objective of the present research was to design a system capable of helping to synchronize the sugar cane harvest machine with the wagon. The communication between tractor and harvest machine is wireless. Two ultrasound sensors coupled to the elevator and a microprocessor manage such information, generating a correct synchronization among the machines. The system was tested in laboratory and on field performing its function adequately, maintaining the two machines in synchronization, indicating and alerting the operators their relative positions. The developed system reduced the sugar cane lost in 60 kg ha-1 comparing to the harvest with the system turned off.
Synchronicity from Synchronized Chaos
Gregory S. Duane
2015-03-01
Full Text Available The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related eventsmysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind and matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1 synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2 the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable interpretations if the quantum world resides on a generalized synchronization “manifold”.
Single-Phase Hybrid Switched Reluctance Motor for Low-Power Low-Cost Applications
Lu, Kaiyuan; Rasmussen, Peter Omand; Jakobsen, Uffe
2011-01-01
This paper presents a new single-phase, Hybrid Switched Reluctance (HSR) motor for low-cost, low-power, pump or fan drive systems. Its single-phase configuration allows use of a simple converter to reduce the system cost. Cheap ferrite magnets are used and arranged in a special flux concentration...... manner to increase effectively the torque density and efficiency of this machine. The efficiency of this machine is comparable to the efficiency of a traditional permanent magnet machine in the similar power range. The cogging torque, due to the existence of the permanent magnetic field, is beneficially...
Development and analysis of U-core switched reluctance machine
Jæger, Rasmus; Nielsen, Simon Staal; Rasmussen, Peter Omand
2016-01-01
these disadvantages have been presented, but not all of them have been demonstrated practically. This paper presents a practical demonstration and assessment of a segmented U-core SRM, which copes with some of the disadvantages of the regular SRM. The U-core SRM has a segmented stator, with a short flux path...
Control strategies for brushless doubly fed reluctance machines
Jovanovic, Milutin; Betz, Robert
2001-01-01
Paper presents the development and results of comprehensive comparative analysis of different vector control strategies for performance optimisation of the BDFRM being considered as a viable cost-effective brushless alternative to traditional brush and less reliable solutions in applications with limited variable speed ranges (such as wind turbines). Australian Research Council and EPSRC projects.
Switched reluctance motor optimal geometry design
Liviu Neamt
2010-12-01
Full Text Available This paper deals with the Switched Reluctance Motor (SRM analysis using Finite Element Method (FEM for geometrical optimization in terms of volume ratio of torque on the rotor, the so-called specific torque. The optimization parameter is the pair: stator and rotor pole angles, which forms a crucial part of the design process.
Using Nooks to Hook Reluctant Readers
Dierking, Rebecca
2015-01-01
This article presents the findings of a two-year qualitative study of electronic reading device use with high school sophomores, most of whom self-identified as reluctant or struggling readers. Electronic readers were used primarily in one weekly fifty-minute class period, during silent sustained reading, wherein students chose freely their texts.…
Orlando Lázaro Rodríguez González
2011-02-01
Full Text Available Este trabajo resuelve, haciendo uso de las facilidades que brinda el MATLAB, de forma cuasi analítica,este problema.El software sigue los mismos pasos que realiza manualmente por el método tradicional. Fueimplementado el método de la fuerza magnetomotriz. Para el ajuste de la curva en el tramo saturado seemplea una aproximación según la función arcotangente, en el sentido de los mínimos cuadrados. Elpunto intercepción entre curvas se calcula con métodos numéricos, hasta una precisión que supera la quepueden tener los datos del experimento. Está destinado para su uso en la industria y para la docencia enlas universidades Synchronous Machine tests, such as no load, short circuit and zero power factor, are achieved to traceZero Power-factor, Regulation and External Load characteristics, in addition to Voltage Regulation for anygiven state. To carry out this results we are familiarized with graphical methods, which are cumbersomeand imprecise. This is a new cuasi analytic approach to this problem by means of a MATLAB software.Algorithm is similar to that followed by someone who is carrying out solutions by traditional way. It wasimplemented Magneto Motriz Force method. Saturation was approached to an inverse tangent curve in aleast means square sense. To compute the interception point between curves it was used numericalmethods which achieved a precision higher than experiments offer.This software is intended to be usedeither in Indutry or in universities with academic purpose.
Sensored and sensorless speed control methods for brushless doubly fed reluctance motors
Jovanovic, Milutin
2009-01-01
The study considers aspects of scalar V/f control, vector control and direct torque (and flux) control (DTC) of the brushless doubly fed reluctance machine (BDFRM) as a promising cost-effective alternative to the existing technological solutions for applications with restricted variable speed capability such as large pumps and wind turbine generators. Apart from providing a comprehensive literature review and analysis of these control methods, the development and results of experimental verif...
New neural synchronization learning rule based on tree parity machine%基于树形奇偶机的神经网络同步新学习规则
梁一峰; 廖晓峰; 任晓霞
2013-01-01
To solve the low speed of synchronization, a new learning rule was proposed by employing Tree Parity Machine (TPM). By setting queues to record the results of each communication in the synchronization process, this rule estimated the degree of synchronization of the two TPMs communicating with each other in real time. According to the results of estimation, the rule selected appropriate values to modify the weights, appropriately increased weight modifications in the lower degree of synchronization and reduced weight modifications in the higher degree of synchronization. Finally, the simulation results show that synchronization efficiency is improved more than 80% by applying new learning rule. Meanwhile, it is also indicated that the rule is computationally inexpensive and it improves the security of communication compared to the classic learning rules.%针对神经密码同步速度慢的问题,基于树形奇偶机(TPM),提出修改权值的新规则,在同步过程中设置队列用来记录每次通信的结果,实时估计两个互相通信的树形奇偶机的同步程度,并根据估计的结果决定权值修改幅度,在同步程度较低时适当增大权值修改量,在同步程度较高时适当减小权值修改量.仿真实验结果表明,应用新学习规则后同步效率提高了80％以上,同时与几种经典学习规则相比,计算开销更小,安全性得到进一步提高.
Variable-Reluctance Motor For Electric Vehicles
Lang, Jeffrey H.
1987-01-01
Report describes research on variable-reluctance electric-motor drive for eventual use in electric-vehicle propulsion. Primary design and performance criteria were torque and power output per unit mass of motor, cost, and drive efficiency. For each criterion, optimized drive design developed, and designs unified to yield single electric-vehicle drive. Scaled-down motor performed as expected. Prototype of paraplegic lift operated by toggle switch and joystick. Lift plugs into household electrical outlet for recharging when not in use.
蔡然; 杨俊华; 杨梦丽; 潘观海
2015-01-01
In order to identify the parameters of the synchronous machine , the relationship of the d , q-axis flux link-age with stator current and excitation voltage was studied , and a model of the synchronous machine was built with cur-rent as state variables .By analyzing the standstill frequency response curves , the gain and phase of different parame-ters with various frequencies were obtained so as to replace the relevant parts in the characteristic transfer function e -quations which represented the d , q-axis electromagnetic parameters .The mathematic model and the state-space equa-tions of the synchronous machine were simplified .The data processing method was improved and the parameters of the machine were identified based on the status analysis results of the machine at the open field excitation winding and the open stator winding .The parameters had better consistency than the measured parameters with other test methods , and therefore the effectiveness of the proposed parameter identification method was verified .%针对同步电机参数辨识问题，以全电流为状态变量，研究同步电机d、q轴磁链与定子电流及励磁电压的关系，建立电机的数学模型。通过分析静止频率响应试验曲线，获得不同频率下各测试参数的增益和相位，替换d、q轴电磁参数特性传递函数方程中的相关部分，简化电机数学模型及其状态空间方程。基于励磁和定子回路开路时电机状态的分析结果，改进数据处理过程，辨识电机参数，对比采用其它方法测取的结果，有较好的一致性，所提参数辨识方法的有效性得以验证。
Control method of high-speed switched reluctance motor with an asymmetric rotor magnetic circuit
Bogusz Piotr
2016-12-01
Full Text Available In the paper, the modified (compared to the classical asymmetric half-bridge converter for a switched reluctance machine with an asymmetric rotor magnetic circuit was analysed. An analysis for two various structures of switched reluctance motors was conducted. The rotor shaping was used to obtain required start-up torque or/and to obtain less electromagnetic torque ripple. The discussed converter gives a possibility to turn a phase off much later while reduced time of a current flows in a negative slope of inductance. The results of the research in the form of waveforms of currents, voltages and electromagnetic torque were presented. Conclusions were formulated concerning the comparison of the characteristics of SRM supplied by the classic converter and by the one supplied by the analysed converter.
Blaabjerg, F.; Jensen, F.; Kierkegaard, P.; Pedersen, J.K.; Rasmussen, P.O.; Simonsen, L.
1999-03-01
The aim of the project is to design, construct and optimise the control of Switched Reluctance Motors with and without permanent magnets. The expectation was an increased efficiency and a decreased material consumption. The project included originally three types of SR-motors, two with a nominal number of revolutions of 3.000 rpm and one motor with a nominal number of revolutions of 50.000 rpm. The project was changed to focus on one motor with a nominal number of revolutions of 6.000 rpm, one with a nominal number of revolutions of 50.000 rpm and one two-phased low-voltage motor with a nominal number of revolutions of 2.000 rpm. The motors had different outputs of 2,7 kW, 0,9 kW and 3 kW, respectively. For this purpose an advanced simulation programme for Switched Reluctance Motors is developed. The programme differs from other programmes by being able to simulate multi-disciplinary such as vibrations and acoustic noise. It is even possible to play the sound. In this connection completely new models are developed. It is also possible to simulate different grid connected converters. Input to the simulation programme is finite element calculations, geometry of the motor and calculations or data from an advanced characterisation system for Switched Reluctance Motors. New methods to control the current in Switched Reluctance Motors are developed, which particularly make quick dynamics possible in a digitally controlled current without use of special noise filters. The method will soon have industrial use. Other new methods have emerged, which secure that the system all the time works with the maximum efficiency irrespective of load. In some cases an efficiency improvement of 10 % is obtained compared to a classic control of the Switched Reluctance Motor. (EHS) EFP-94; EFP-95; EFP-98. 16 refs.
Control Code for Bearingless Switched-Reluctance Motor
Morrison, Carlos R.
2007-01-01
A computer program has been devised for controlling a machine that is an integral combination of magnetic bearings and a switched-reluctance motor. The motor contains an eight-pole stator and a hybrid rotor, which has both (1) a circular lamination stack for levitation and (2) a six-pole lamination stack for rotation. The program computes drive and levitation currents for the stator windings with real-time feedback control. During normal operation, two of the four pairs of opposing stator poles (each pair at right angles to the other pair) levitate the rotor. The remaining two pairs of stator poles exert torque on the six-pole rotor lamination stack to produce rotation. This version is executable in a control-loop time of 40 s on a Pentium (or equivalent) processor that operates at a clock speed of 400 MHz. The program can be expanded, by addition of logic blocks, to enable control of position along additional axes. The code enables adjustment of operational parameters (e.g., motor speed and stiffness, and damping parameters of magnetic bearings) through computer keyboard key presses.
E-core transverse flux machine with integrated fault detection system
Rasmussen, Peter Omand; Runólfsson, Gunnar; Thorsdóttir, Thórunn Ágústa
2011-01-01
The E-core transverse flux machine, which is a variation of the classical Switched Reluctance machine (SRM), have all the basic properties to be considered as a very fault tolerant machine. Every single coil in the machine is isolated from the each others both magnetic, electrical and to some ext...... is believed to be a strong candidate for fault tolerant electrical machine applications....
Torque Ripple Reduction of Reluctance Torque Assisted Motors Using Asymmetric Flux Barriers
Hiramoto, Kenji; Takeda, Yoji; Sanada, Masayuki; Morimoto, Shigeo
Interior permanent magnet synchronous motor (IPMSM) is efficient and can be operated in wide speed region; therefore it is used widely. However, torque ripple of reluctance torque assisted motors, for example IPMSM and synchronous reluctance motor (SynRM), is very large. The skew is known in the prior art as a torque ripple reduction method of AC motors. Although the skew is effective for torque ripple reduction, structure is complicated and it has the disadvantage that average torque will decrease. The discontinuous variation of magnetic resistance between flux barriers and teeth cause the torque ripple. In this paper, in order to ease the discontinuous variation of magnetic resistance, flux barriers are asymmetrically designed so that the relative position relation between flux barriers and teeth may not be in agreement as much as possible. As a result, the torque ripple can be reduced dramatically without the average torque decrease. The experimental motor has been fabricated and the results of measuring torque ripple prove the validity of the torque ripple reduction using asymmetric flux barriers.
Rotor Losses in a Switched Reluctance Motor - Analysis and Reduction Methods
Schweighofer, B.; Recheis, M.; Fulmek, P.; Wegleiter, H.
2013-01-01
Due to the increasing hybridization and electrification of vehicles, flywheel energy storage devices are an important area of research. In automotive application besides the weight criteria, some additionally constrains, such as size, eﬃciency and especially cost have to be fulfilled. Therefore typically a compact design, in which the rotor of the needed electrical machine simultaneously acts as storage mass is chosen. Since the machine is running in vacuum and the rotor can dissipate its heat only by means of thermal radiation or through the bearings if conventional bearings are used, the rotor losses play a vital role. In this work the rotor losses of a switched reluctance machine are analyzed in detail and a method to reduce the rotor losses is proposed.
"Reluctant Participants" in Role Play Simulations: Stage Fright or Bewilderment?
Saunders, Danny
1985-01-01
Discusses factors contributing to participant reluctance in role playing--isolation of role play from the curriculum; lack of interest because of perceived irrelevance to social psychological themes; and acting anxiety. A two-step design which involves gradual role play introduction and observation by reluctant participants is suggested as a…
Chou, S.Y. [ELETRONORTE, Brasilia (Brazil); Liu, H. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Pedroso, A. de [CEPEL, Rio de Janeiro, RJ (Brazil)
1991-12-31
The performance of an adapted stabilizer additional sign for a synchronous power generator connected to an infinite bar is analysed. The operation modus of the system is fully explained and its theoretical basis is described. A comparison between the performance of the adapted system and a conventional one is performed. 8 refs., 18 figs., 1 tab.
苏颖毅
2012-01-01
A layout scheme of the electric drive system of a pure electric vehicle was introduced in this paper.The longitudinal dynamics model of the electric vehicle was built , from which the driving resistance was derived and then transformed to an equivalent resistance torque on the axis of the electric machine .The mathe-matical model of a permanent magnet synchronous machine was built in the two phase rotating reference frame and the motion equation of the electric machine with respect to the driving resistance was given .The necessity of the flux -weakening control was pointed out according to the voltage and current limitations of the three phase in -verter.A surface mounted permanent magnet synchronous machine was chosen and the relative flux -weakening control was put forward.By means of the simulation in Matlab /Simulink it was concluded that the flux -weake-ning control can effectively widen the rotational speed range of the electric machine , which can raise the maxi-mum speed of the electric vehicle.% 介绍了一种纯电动车电力驱动系统布置方案。建立电动车纵向动力学模型，得出电动车行驶阻力，并将其等效到电机输出端。在两相旋转坐标系下建立永磁同步电机数学模型，结合电动车行驶阻力，推出电机运动方程。然后选用表贴式永磁同步电机，提出相应的弱磁控制策略。通过在 Matlab/Simulink 中的仿真验证，得出弱磁控制能有效拓宽永磁同步电机转速范围，提升电动车最高运行速度。
a novel strategy for raising the unit output of large synchronous ...
Dr Obe
magnetic structure to amplify Xd/Xq ratio on which the reluctance output power depends ... Keywords: Xd/Xq ratio, modified q-axis reactance Xq mmf, permeance and flux density distributions, ... Machines without rotating windings therefore.
Louis, Jean-Paul
2013-01-01
Synchronous motors are indubitably the most effective device to drive industrial production systems and robots with precision and rapidity. Their control law is thus critical for combining at the same time high productivity to reduced energy consummation. As far as possible, the control algorithms must exploit the properties of these actuators. Therefore, this work draws on well adapted models resulting from the Park's transformation, for both the most traditional machines with sinusoidal field distribution and for machines with non-sinusoidal field distribution which are more and more used in
Electromagnetic Forces in a Hybrid Magnetic-Bearing Switched-Reluctance Motor
Morrison, Carlos R.; Siebert, Mark W.; Ho, Eric J.
2008-01-01
Analysis and experimental measurement of the electromagnetic force loads on the hybrid rotor in a novel hybrid magnetic-bearing switched-reluctance motor (MBSRM) have been performed. A MBSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The MBSRM discussed in this report has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of four stator poles, while a second set of four stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Static torque and radial force analysis were done for rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental and the theoretical radial force loads predictions was obtained with typical magnetic bearing derating factors applied to the predictions.
Sundaram Maruthachalam
2011-01-01
Full Text Available Problem statement: The Switched Reluctance Motor (SRM is an old member of the Electric Machines Family. Its simple structure, ruggedness and inexpensive manufacturing capability make it more attractive for Industrial applications. Now, the applications of switched reluctance motors in various industrial fields are tried by many engineers. However, switched reluctance motors are not used so far in submersible underwater motor for agriculture purposee. The torque developed by an SRM is dependent on the change of flux-linkage and rotor position. The flux linkage characteristic of the motor is required to make the control circuit. Since the SRM is non-linear in nature, estimation and calculation of the flux linkage characteristics is very difficult. Approach: With the flux tube method concept a simple algorithm is being developed in a MATLAB. ANSYS Software is used to determine the flux distribution at various rotor positions. Results: The aligned and unaligned flux linkage values for theoretical calculation at a current of 7 A is 72.7 mwb and 13.79 mwb respectively. With FEA simulation the obtained value is 92.73 mwb and 19.175. Conclusion: In this and, a simplified method for the determination of flux linkage characteristics of submersible SRM using MATLAB has been presented. The obtained value has been validated with the ANSYS FEM method. the calculated unaligned and aligned inductance values of a 4- phase, 3 hp, 220 V Submersible SRM using simplified MATLAB method very much matches with the ANSYS FEM Method.
Ćalasan Martin P.
2013-01-01
Full Text Available This paper presents mechanical characteristics of Switched Reluctance Motor (SRM when it operates in Discontinuous Conduction Mode (DCM or in Continuous Conduction Mode (CCM, i.e. when the current through the phase coils (windings flows discontinuously or continuously. Firstly, in order to maximize the output power of SRM optimization of its control parameters was performed, such that the peak and RMS values of the current do not exceed the predefined values. The optimal control parameters vs. rotation speed, as well as the corresponding characteristics of torque, power and efficiency. It is shown that with CCM the machine torque (power, at high speed, can be increased.
Hybrid Switch Reluctance Drives For Pump Applications
Jakobsen, Uffe
The initial research problem is to investigate an alternative motor drive to the existing permanent magnet synchronous and brushless DC-motor drives for pump applications. A review of different motor types showed that a possible candidate for another low cost permanent magnet motor may be the sin......The initial research problem is to investigate an alternative motor drive to the existing permanent magnet synchronous and brushless DC-motor drives for pump applications. A review of different motor types showed that a possible candidate for another low cost permanent magnet motor may...... a stroke. The changes of speed controller output during a stroke, may give rise to undesired low frequency oscillations in the speed controller output. A time variant speed controller is presented in the thesis that does not suffer from these issues. Like the brushless DC-motor (BLDC) and the permanent...
张超; 李岩; 王冬梅
2011-01-01
This paper introduces a modeling method of Brushless Synchronous Machines' model. A starter/generator system is Based on the model. By analysing the Typical transition process (from no load to load and the load to the three -2phase output short circuit) ,we can prove the correctness and effectiveness of Matlab simulation model.%运用Matlab中的PSB模块库和Simu link模块库,建立了无刷同步电机模型以及该模型的起动发电系统；通过对该系统发电状态下,由空载到负载和由空载到三相输出短路等典型过渡过程仿真分析,证明了所建Matlab仿真模型的正确性和有效性.
Timofeev, Igor; Bazhenov, Maksim; Seigneur, Joseé; Sejnowski, Terrence
2011-01-01
Summary Neuronal synchronization occurs when two or more neuronal events are coordinated across time. Local synchronization produces field potentials. Long-range synchronization between distant brain sites contributes to the electroencephalogram. Neuronal synchronization depends on synaptic (chemical/electrical), ephaptic, and extracellular interactions. For an expanded treatment of this topic see Jasper’s Basic Mechanisms of the Epilepsies, Fourth Edition (Noebels JL, Avoli M, Rogawski MA, Olsen RW, Delgado-Escueta AV, eds) published by Oxford University Press (available on the National Library of Medicine Bookshelf [NCBI] at www.ncbi.nlm.nih.gov/books). PMID:24850952
Reconstruction of the Switched Reluctance Motor Stator
El-Kharashi, Eyhab; Hassanien, Hany M.
2012-01-01
The paper re-designs the conventional 6/8 switched reluctance motor (SRM) by a particular way to minimize the losses. The flux loops are shortened by making each two stator teeth incorporated in one magnetic circuit only. Subsequently the flux does not cross in some iron parts of the stator core backs. These unused iron sections are taken off consequently the iron losses decreased. Now the stator consists of three separated sections and they are fixed inside non-magnetic cylinder. The copper losses also are decreased because less copper windings are used to produce the same amount of the output torque as the flux paths become short then the flux density increases. The analysis and comparison of the 6/8 SRM before and after the re-design process are presented. A m files Matlab software is used to simulate the dynamic performance. Then the paper proceeds to examine different control techniques to the new design. The hysteresis and PI controllers are used as classical method to control the SRM. Then the artificial neural network (ANN) is used to test the new control techniques.
肖甘
2013-01-01
本文以永磁同步电动机为基础,研究了直接滑模电流控制策略,该策略对参数变化以及外界干扰的鲁棒性较强,从而广泛应用于电气传动控制领域.设计了新颖的直接滑模电流控制器代替传统的PI电流控制器,并且采用了开关表查询方式加快了动态响应速度.最后基于TMS320DSP28335控制器对永磁同步电动机直接滑模电流控制控制系统进行实验验证,结果表明所设计的控制器动态响应较快,抗干扰能力较强.%This paper researched on direct sliding mode current control of a permanent magnet synchronous machine.Due to the robustness to parameters variations and external disturbances,sliding mode controllers were widely used for the control of electrical drives.A novel direct sliding mode current controller was designed to substitute the traditional PI current controller,and switch table was used to speed up the dynamic response.As a result,the experiment of permanent magnet synchronous machine direct sliding mode current control system based on TMS320DSP28335 controller was finished.The experimental results illustrate this designed controller has faster dynamic response and stronger anti-interference ability.
Preliminary Design of Reluctance Motors for Light Electric Vehicles Driving
TRIFA, V.
2009-02-01
Full Text Available The paper presents the aspects regarding FEM analysis of a reluctant motor for direct driving of the light electric vehicles. The reluctant motor take into study is of special construction suitable for direct drive of a light electric vehicle. It is an inverse radial reluctant motor, with a fixed stator mounted on front wheel shaft and an external toothed rotor fixed on the front wheel itself. A short presentation of preliminary design is continued with the FEM analysis in order to provide the optimal geometry of the motor and adequate windings.
Reluctance Network Based Dynamic Analysis in Power Magnetics
Nakamura, Kenji; Ichinokura, Osamu
This paper describes a reluctance network based dynamic analysis method used in the field of power magnetics, which is called reluctance network analysis (RNA). It is based on the magnetic circuit method and has some advantages for simulating electrical machinery such as a simple analytical model, high calculation accuracy, and easy to combine with an electric circuit, motion and thermal dynamics. First, the basis of the magnetic circuit method is described. Next, two case studies of RNA, one is a permanent magnet (PM) motor and the another is a switched reluctance (SR) motor, are presented.
开关磁阻电机调速系统及其应用分析%Switched Reluctance Drive System and Its Application Analysis
叶婷
2015-01-01
Thispaper focuses on switched reluctance motor speed control system and application analysis, first, to explore the characteristics and working principle of a switched reluctance electrical and introduce the development of reluctance motor drive system. Secondly,analysis of Switched Reluctance electronic timing system Composition and switched reluctance motor before you install, finally, analyze switched reluctance motor drive system on special occasions, CNC machine tools, electric cars, boats driven control applications.%本文对开关磁阻电机调速系统及应用进行分析，首先，探究开关磁阻电子的特点及工作原理，介绍磁阻电机调速系统的发展情况，其次，分析开关磁阻电子调速系统的构成及开关磁阻电机安装前的准备，最后，分析开关磁阻电机调速系统在特殊场合，数控机床，电动车、船驱动的控制中的应用。
Permanent magnet synchronous and brushless DC motor drives
Ramu, Krishnan
2009-01-01
Presents an introduction to machines, power devices, inverters, and control. This book covers pm synchronous machines, including modeling, implementation, control strategies, flux weakening operations, parameter sensitivity, sensorless control, and intelligent control applications.
李岩; 张超; 王冬梅
2012-01-01
对航空无刷同步电机起动发电系统电动运行的励磁特性进行了理论分析,提出了交直流混合励磁方案,建立了系统的MATLAB/SIMULINK仿真模型。仿真结果表明,主发电机励磁电流平均值随励磁机励磁频率的升高而减小,且主发电机励磁电流脉动率随转速升高有唯一极小值点,该点可作为交直流励磁的切换点。%The excitation characteristic for starter/generator system working on starting process of brushless synchronous machine was analyzed in this paper first,and then a new excitation method is given,it was AC an DC excitation.Based on MATLAB/SIMULINK,the simulation model for the system was built.Simulation results state that the average current of main machine would decrease with the increase of excitation frequency and the rate of variation for excitation current had only one minimum value with the increase of speed,and the value just could be used for switching.
闫波; 李佳
2011-01-01
简要介绍飞刀加工汽车同步器齿套滑块槽时存在的弊病,分析了导致切削颤振的原因.测量了飞刀加工时的主切削力,并以此建立其数学模型;通过改变进给量及切削速度的方法改着了切削振动,提高了生产质量和生产效率.%The machining malady in flying culling for the sliding groove of gear sleeve of automotive synchronizer was introduced and the fat-tors loading to fulling chattet were analyzed. The main rutting force in flying cutler machining was measured lo establish a mathenatical model. Results show that culling vibralion in amended by method of varying feed rate and culling speed, and the produe tionn quality and efficiency are improved.
Benecke, Marcel; Lindemann, Andreas [Magdeburg Univ. (Germany). Inst. fuer Elektrische Energiesysteme; Griepentrog, Gerd [Siemens AG (Germany). Corporate Technology CT T DE
2011-07-01
Permanentmagnet synchronous machines (PMSM) show lower losses compared to induction machines (IM) due to the lack of rotor losses which are typical only for IM. Hence, for many applications with a fixed rotational speed such as fans or pumps the PMSM would be a good choice in case the PMSM is directly connected to the grid without any converter in between at nominal speed. This would be an optimal solution with respect to efficiency and losses. Because the PMSM is not able to speed up when directly connected to the grid, it has normally to be started using a frequency converter or it has to be equipped with a start-up short-circuit cage which would develop an asynchronous torque. A cost effective alternative is to use AC voltage controller or softstarter based on thyristors to speed up the PMSM and bridge the AC voltage controller once the PMSM has reached nominal speed. This paper presents a calculation method to predict the dynamic behaviour of a PMSM when fed by a thyristor-based AC voltage controller. (orig.)
Boussetoua, Mohammed
feeding the hearting system. In recent years, numerous research studies have started on the development of electromechanical system converters for various applications, such as transport by road, rail or aviation. The development of new low-speed, low-weight electric machines and their very high degree of compactness has become a very promising alternative. This project strongly interests many industries in the field of air transport. The transverse flux machine is considered as a compact structure having better mass power compared to other electrical machines. The design of transverse flux machine was the subject of an electromagnetic study. Also, the analytical study helped to determine the overall dimensions of the machine. The study was followed by a validation phase of the analytical model using numerical simulations. These two studies were intended to determine changes in the characteristics of the transverse flux machine according to the different geometric dimensions of its active parts. From the calculations made using analytical and numerical models, a prototype of the transverse flux machine (600 W, 320 RPM) was designed and manufactured in the AMIL laboratory at the Universite du Quebec a Chicoutimi (UQAC). A bench test was conducted to compare the theoretical and experimental results. The measurements obtained on this prototype were compared with the theoretical results. This phase of the study demonstrates with satisfaction, the reliability of the theoretical models developed. Finally, a new configuration of this machine has been proposed. Numerical simulation results of this structure are particularly encouraging and require further investigations. For logistical and financial reasons, the prototype of this configuration has not been manufactured. (Abstract shortened by UMI.)
Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes
Dirba J.
2017-04-01
Full Text Available The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force or angle ε (angle between rotor direct axis and armature magnetomotive force axis is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.
Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes
Dirba, J.; Lavrinovicha, L.; Dobriyan, R.
2017-04-01
The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.
Inductance and Active Phase Vector Based Torque Control for Switched Reluctance Motor Drives.
Kalpathi, Ramani Raman
The Switched Reluctance Motor (SRM) drive technology has developed significantly over the last few years. The simplicity in both motor design and power converter requirement along with the availability of high frequency, high power semiconductor switches have made SRMs compete with conventional adjustable speed drive technologies. The subject of winding current control in switched reluctance machines has always been associated with the shaft position information. The use of inductance for direct commutation control is the central subject of this dissertation. In contrast to the conventional methods based on position commutation, new methods of control based on inductance commutation are presented. The object of a commutation algorithm is to switch the currents in the phase coils, in order to provide continuous energy conversion with maximum torque output for a given unit of input current. Since torque production in a SRM is based on the concept of variable reluctance, it makes more sense to observe the instantaneous phase inductance or reluctance instead of estimating the rotor position. The inductance sensors observe the machine parameters and provide sufficient information on the electrical characteristics of the coils. This control strategy avoids the inductance to position transformation blocks conventionally used in SRM control systems. In a typical SRM, the phase coils have a nonlinear behavior of inductance due to effects of current saturation. Also the parameters of one phase coil differ from those of the other due to manufacturing tolerances or due to bearing wear. In such cases, the algorithms written during the stage of manufacturing may not be valid after parameter changes. Optimizing torque production in the event of phase asymmetry and saturation is developed in this research. Indirect sensors connected to the active phase coil of the SRM are based on sensing the flux level in the active coil. New commutation algorithms based on flux sensing concepts
Stirling machine operating experience
Ross, B. [Stirling Technology Co., Richland, WA (United States); Dudenhoefer, J.E. [Lewis Research Center, Cleveland, OH (United States)
1994-09-01
Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that stirling machines are capable of reliable and lengthy operating lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and are not expected to operate for lengthy periods of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered. The record in this paper is not complete, due to the reluctance of some organizations to release operational data and because several organizations were not contacted. The authors intend to repeat this assessment in three years, hoping for even greater participation.
LHC synchronization test successful
The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/
彭纪昌; 刘卫国; 马鹏; 毛帅
2015-01-01
随着多电飞机、全电飞机的高速发展,三级式航空无刷同步电机因兼顾高功率密度及功率因数可调等优势得到广泛应用.由于三级式电机中主发电机的凸极特性,转子磁场位置的变化会影响定子铁芯的饱和程度,从而造成定子电感值的变化.该文分析了三级电机饱和状态下电感值的变化规律,并在此基础上利用主发电机的凸极特性,采用脉冲式电压注入法进行转子位置的检测.在实际应用中,三级式电机在起动时采用单相交流励磁方式产生励磁电流,导致主发电机励磁电流产生较大脉动,该脉动信号的干扰使传统的定位方法难以准确估计出转子初始位置.该文通过对励磁机输出特性的分析,建立集励磁机和主发电机的一体化数学模型,提出采用傅里叶算法对响应电流数据进行分析,以获取转子初始位置的方法.实验结果表明,该文方法能够有效消除励磁机脉动干扰,实现转子位置的精确定位,同时该文算法计算量较低,易于在嵌入式系统中实现.%Along with the fast development of more electric aircrafts (MEA) and all electric aircrafts (AEA), the three-stage aviation brushless synchronous machines are widely used, which adopt the brushless structure and combine the merits of high power density and adjustable magnetic fields at the same time. According to saliency of the main generator of three-stage brushless synchronous machines, the information of rotor position is implied in performances of stator inductances due to the magnetic saturation effect. This paper studied the variation of inductances then estimated the initial rotor position of main generators by injecting modulated pulse voltage vectors. The three-stage aviation brushless synchronous machines are excited by single-phase AC during the starting period. The excitation current of the main generator contains severe pulsating components, thus the traditional methods can not
Le Doeuff, René
2013-01-01
In this book a general matrix-based approach to modeling electrical machines is promulgated. The model uses instantaneous quantities for key variables and enables the user to easily take into account associations between rotating machines and static converters (such as in variable speed drives). General equations of electromechanical energy conversion are established early in the treatment of the topic and then applied to synchronous, induction and DC machines. The primary characteristics of these machines are established for steady state behavior as well as for variable speed scenarios. I
Why are junior doctors reluctant to consult attending physicians?
Swank, Otto H
2010-03-01
A physician performs two tasks: making diagnoses and determining treatments. To reduce medical error, junior doctors are supposed to consult their supervisors when they face uncommon circumstances. However, recent research shows that junior doctors are reluctant to do so. This paper presents a model that explains (i) which junior doctors shy away from consulting; (ii) when junior doctors are reluctant; (iii) the importance of protocols in the medical sector; and (iv) when consulting is a sign of strength or a sign of weakness. Furthermore, I show that encouraging junior doctors to consult by investigating mishaps leads to another distortion: they will give too much weight to own assessments.
Operation Analysis for Electrical Machinery Based on Reluctance Network
Nakamura, Kenji; Ichinokura, Osamu
In this paper, we describe the basis of a magnetic circuit method and introduce a reluctance network analysis (RNA) proposed by authors. The RNA, which is based on the magnetic circuit method, has some suitable merits for simulating electrical machineries such as a simple analytical model, ease of coupled analysis with electrical circuits, motion, and thermal fields. In addition to these merits, a general-purpose circuit simulator like “SPICE" can be utilized as a solver. We present some applications of the RNA to operation analysis for an orthogonal-core, a switched reluctance motor, and a permanent magnet generator.
Reinforcement procedure in the treatment of reluctant speech.
Morin, C; Ladouceur, R; Cloutier, R
1982-06-01
The efficacy of a positive reinforcement contingency procedure was evaluated in the treatment of a 6-year old boy with reluctant speech. The intervention was conducted in the kindergarten classroom and the teacher served as therapist. Using an ABABB' single case experimental design, positive reinforcement was found to be effective for increasing the child's verbal responsiveness. At a 1-year follow-up, therapeutic benefits were maintained at an optimal level. The present results bring support to the use of reinforcement procedures in the case of reluctant speech.
Dynamic Modeling and Simulation of a Switched Reluctance Motor in a Series Hybrid Electric Vehicle
Siavash Sadeghi
2010-04-01
Full Text Available Dynamic behavior analysis of electric motors is required in order to accuratelyevaluate the performance, energy consumption and pollution level of hybrid electricvehicles. Simulation tools for hybrid electric vehicles are divided into steady state anddynamic models. Tools with steady-state models are useful for system-level analysiswhereas tools that utilize dynamic models give in-depth information about the behavior ofsublevel components. For the accurate prediction of hybrid electric vehicle performance,dynamic modeling of the motor and other components is necessary. Whereas the switchedreluctance machine is well suited for electric and hybrid electric vehicles, due to the simpleand rugged construction, low cost, and ability to operate over a wide speed range atconstant power, in this paper dynamic performance of the switched reluctance motor for eseries hybrid electric vehicles is investigated. For this purpose a switched reluctance motorwith its electrical drive is modeld and simulated first, and then the other components of aseries hybrid electric vehicle, such as battery, generator, internal combusion engine, andgearbox, are designed and linked with the electric motor. Finally a typical series hybridelectric vehicle is simulated for different drive cycles. The extensive simulation results showthe dynamic performance of SRM, battery, fuel consumption, and emissions.
史涔溦; 邱建琪; 金孟加; Friedrich W.Fuchs
2005-01-01
提出一种用于永磁同步电动机的基于磁链误差矢量补偿的直接转矩控制(EFVC-DTC)策略,给出了磁链误差矢量的估计算法,并将该控制策略下的稳态和动态运行性能与常规DTC进行比较.仿真及实验结果表明EFVC-DTC可以使电力开关器件工作在基本固定的频率上,磁链和转矩脉动显著减小,比常规DTC具有更优越的稳态性能,而动态转矩响应几乎与常规DTC相同.%A modified direct torque control strategy based on error flux linkage vector compensation (EFVC-DTC) for permanent magnet synchronous machines (PMSM) is presented. The theoretical background of EFVC-DTC is introduced and an algorithm to estimate the flux linkage error is proposed. The steady state and dynamic performances of EFVC-DTC have been compared with those of the conventional direct torque control (DTC). The simulation and experimental results confirm that both flux linkage and torque ripples are significantly reduced in EFVC-DTC with a fixed switching frequency while the dynamic torque response isalmost as good as the basic DTC.
Boldea, Ion
2005-01-01
This work begins with an introduction to energy resources and the main electric energy conversion solutions, along with efficiency and environmental merits and demerits. The classification and principles of various electric generator topologies are covered alongside their power ratings and main applications including constant-speed synchronous gene
Hua, Wei; Qi, Ji; Jia, Meng
2017-05-01
Switched reluctance machines (SRMs) have attracted extensive attentions due to the inherent advantages, including simple and robust structure, low cost, excellent fault-tolerance and wide speed range, etc. However, one of the bottlenecks limiting the SRMs for further applications is its unfavorable torque ripple, and consequently noise and vibration due to the unique doubly-salient structure and pulse-current-based power supply method. In this paper, an inductance Fourier decomposition-based current-hysteresis-control (IFD-CHC) strategy is proposed to reduce torque ripple of SRMs. After obtaining a nonlinear inductance-current-position model based Fourier decomposition, reference currents can be calculated by reference torque and the derived inductance model. Both the simulations and experimental results confirm the effectiveness of the proposed strategy.
Engaging Reluctant Readers in a French Immersion Classroom
Capina, Amanda Borton; Bryan, Gregory
2017-01-01
Reading engagement is like a puzzle consisting of many pieces to emplace for successful engagement to occur. The author, a French Immersion teacher/researcher, found that many of her grade one reluctant readers--those students who could read but chose not to--approached reading with some pieces of the puzzle. They had strategies and knowledge but…
张钊; 陈涛; 周勇
2014-01-01
Aiming at the complication of introducing the control theory such as adaptive, fuzzy, neural networks, etc to the permanent magnet synchronous machine (PMSM) control system, and the required control expectation can hardly be fulfilled, the vector control system of PMSM is simulated in Matlab/Simulink. Based on the analysis of PMSM model and the control theory of space vector pulse width modulation (SVPWM), the simulation model of vector control system of PMSM is designed. The simulation result shows that the system runs stably, and gains good performance of static and dynamic response, complies with the theory analysis, provides the theoretical foundation of the design and analysis of real system, it can also be taken as reference for the system debugging.%针对将自适应、模糊、神经网络等控制理论引入永磁同步电机(permanent magnet synchronous machine， PMSM)控制系统中设计太过复杂，难以达到较理想控制效果的问题，在 Matlab/Simulink 环境下，基于矢量控制策略对 PMSM 控制系统进行建模仿真。分析 PMSM 数学模型和空间电压矢量脉宽调制(space vector pulse width modulation，SVPWM)控制原理，建立基于SVPWM的PMSM控制系统仿真模型。仿真结果表明：该系统运行平稳，具有较好的静态和动态性能，符合理论分析，能为实际系统的设计与分析提供理论依据，对工程实践中系统的调试具有一定的指导意义。
Morrison, Carlos R.; Siebert, Mark W.; Ho, Eric J.
2007-01-01
Analysis and experimental measurement of the electromagnet force loads on the hybrid rotor in a novel bearingless switched-reluctance motor (BSRM) have been performed. A BSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The BSRM has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of stator poles. A second set of stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Analysis was done for nonrotating rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental results and the theoretical predictions was obtained with typical magnetic bearing derating factors applied to the predictions.
Ali Asghar Memon; Imtiaz Hussain; Muhammad Aslam Uqaili
2013-01-01
This paper presents a gate driver circuit for the switching devices used in the asymmetrical converter for a switched reluctance machine with reduced number of isolated dc/dc converters. Isolation required in the gate driver circuit of switching devices is indispensable. For the purpose of isolation different arrangements may be used such as pulse transformers. The dc/dc converter for isolation and powering the gate drive circuits is suitable, cheaper in cost and simple to implement. It is al...
Application of Fuzzy Logic in Control of Switched Reluctance Motor
Pavel Brandstetter
2006-01-01
Full Text Available The flux linkage of switched reluctance motor (SRM depends on the stator current and position between the rotor and stator poles. The fact determines that during control of SRM current with the help of classical PI controllers in a wide regulation range unsatisfied results occur. The main reasons of the mentioned situation are big changes of the stator inductance depending on the stator current and rotor position. In a switched reluctance motor the stator phase inductance is a non-linear function of the stator phase current and rotor position. Fuzzy controller and fuzzy logic are generally non-linear systems; hence they can provide better performance in this case. Fuzzy controller is mostly presented as a direct fuzzy controller or as a system, which realizes continued changing parameters of other controller, so-called fuzzy supervisor. Referring to the usage of fuzzy logic as a supervisor of conventional PI controller in control of SRM possible improvement occurs.
Automated solar-cell-array assembly machine
Costogue, E. N.; Mueller, R. L.; Person, J. K.; Yasui, R. K.
1978-01-01
Continuous-feeding machine automatically bonds solar cells to printed-circuit substrate. In completed machine, cells move to test station where electrical characteristics could be checked. If performance of cell is below specifications, that cell is marked and removed. All machine functions are synchronized by electronics located within unit. It may help to lower costs in future solar-cell production.
Direct energy converter controllers for switched reluctance motor operation
Goodman, Andrew Simon
2007-01-01
There is increasing demand for simple motor drives offering high reliability and fault tolerance in applications such as the aerospace actuator industry, with the development of `more electric aircraft'. This thesis presents a motor drive employing a switched reluctance motor, the novel single sided matrix converter, and a novel double band hysteresis based control scheme for control of the converter, implemented using a field programmable gate array (FPGA). The single sided matrix co...
Switch Reluctance Motor Control Based on Fuzzy Logic System
S. Aleksandrovsky
2012-01-01
Full Text Available Due to its intrinsic simplicity and reliability, the switched reluctance motor (SRM has now become a promising candidate for variable-speed drive applications as an alternative induction motor in various industrial application. However, the SRM has the disadvantage of nonlinear characteristic and control. It is suggested to use controller based on fuzzy logic system. Design of FLS controller and simulation model presented.
Modulated Field Synchronous Generator for Wind Turbines
Petru Chioncel
2013-01-01
Full Text Available This paper presents a modern electromechanical conversion systemsolution as the modulated field synchronous generator, offering on theone hand, an output voltage with constant frequency in terms of speedvariation of the wind turbine and on the other hand an advantagepower / weight ratio due to the high frequency for which the magneticcircuit of the electric machine is sized. The mathematical model of the modulated field synchronous generator is implemented in MatLABmodeling language, highlighting the command structure on thetransistors bases of the inverter transistors, through which thefunctioning of the electric machine can be studied, especially in terms of the frequency of the delivered voltage.
A New Design of Clock Synchronization Algorithm
Jingmeng Liu
2014-05-01
Full Text Available The introduction of Ethernet makes the distributed network system more flexible and efficient, but it also makes nodes which are far apart from each other unable to work in the same time basis due to the long distance. This is not allowed for the high performance requirements of the system synchronization, such as high-precision multiaxis machining system. This paper presents a high-precision network clock synchronization algorithm, namely, optimal PI clock servo, which imposes a PI controller in order to compensate for the clock drift of each network node. Then a simulation platform established by the toolbox TrueTime is used to verify the stability of the algorithm and compare it with the clock synchronization algorithm of EtherCAT. The results show that the new synchronization algorithm has higher synchronization precision and faster convergence rate.
胡堃; 樊贝; 薛冰
2012-01-01
The structural characteristics and working principle of brushless doubly-fed machine were introduced firstly in this paper. Then Ansoft/Maxwell was used to establish the models of doubly-fed brushless machine, which contain the cage rotor and the reluctance rotor with blocked-magnetic layers. The 2-D transient electromagnetic fields of brushless doubly-fed machine (BDFM) were calculated by finite element method. The magnetic force line and air-gap magnetic fields were got. The air-gap magnetic fields were analysed by the harmonic spectrum. As a result, the blocked-magnetic reluctance rotor contains a better magnetic field modulation effects. The dynamic characteristics of the different BDFMs were researched under the states of single-fed asynchronous operation to natural synchronous, under-synchronous and over-synchronous operations. And the torque and speed had a change with variation in load. The results show that the blocked-magnetic reluctance rotor has a better dynamic characteristics in pulling in three states, and a better stability under load change. And it provide the foundation for the rotor structure design optimization and operating stability intensive research of BDFM.%简要介绍了无刷双馈电机( BDFM)的结构特点和工作原理,利用Ansoft/Maxwell建立笼型转子和磁障式磁阻转子的BDFM模型,进行了二维瞬态电磁场有限元计算,得出电机磁力线分布、气隙磁通密度波形,通过对气隙磁通密度波形的谐波频谱分析,得到了磁障式磁阻转子结构具有较好磁场调制效果.研究了由单馈异步牵入自然同步、亚同步和超同步运行状态的动态响应能力和机械负载突变时的转速转矩变化情况.结果表明磁障式磁阻转子BDFM在由单馈异步牵入自然同步、亚同步和超同步运行状态下,具有较好的动态响应能力,同时在加载时稳定性也较好,为进一步深入研究BDFM转子的优化设计和运行稳定性提供了参考.
Numerical Modal Analysis of Vibrations in a Three-Phase Linear Switched Reluctance Actuator
José Salvado
2017-01-01
Full Text Available This paper addresses the problem of vibrations produced by switched reluctance actuators, focusing on the linear configuration of this type of machines, aiming at its characterization regarding the structural vibrations. The complexity of the mechanical system and the number of parts used put serious restrictions on the effectiveness of analytical approaches. We build the 3D model of the actuator and use finite element method (FEM to find its natural frequencies. The focus is on frequencies within the range up to nearly 1.2 kHz which is considered relevant, based on preliminary simulations and experiments. Spectral analysis results of audio signals from experimental modal excitation are also shown and discussed. The obtained data support the characterization of the linear actuator regarding the excited modes, its vibration frequencies, and mode shapes, with high potential of excitation due to the regular operation regimes of the machine. The results reveal abundant modes and harmonics and the symmetry characteristics of the actuator, showing that the vibration modes can be excited for different configurations of the actuator. The identification of the most critical modes is of great significance for the actuator’s control strategies. This analysis also provides significant information to adopt solutions to reduce the vibrations at the design.
Sakai, Kazuto; Takahashi, Norio; Shimomura, Eiji; Arata, Masanobu; Nakazawa, Yousuke; Tajima, Toshinobu
Regarding environmental and energy issues, increasing importance has been placed on energy saving in various systems. To save energy, it would be desirable if the total efficiency of various types of equipment were increased.Recently, a hybrid electric vehicle (HEV) and an electric vehicle (EV) have been developed. The use of new technologies will eventually lead to the realization of the new- generation vehicle with high efficiency. One new technology is the variable-speed drive over a wide range of speeds. The motor driving systems of the EV or the HEV must operate in the variable-speed range of up to 1:5. This has created the need for a high-efficiency motor that is capable of operation over a wide speed range. In this paper, we describe the concept of a novel permanent magnet reluctance motor (PRM) and discuss its characteristics. We developed the PRM, which has the capability of operating over a wide speed range with high efficiency. The PRM has a rotor with a salient pole, which generates magnetic anisotropy. In addition, the permanent magnets embedded in the rotor core counter the q-axis flux by the armature reaction. Then, the power density and the power factor increase. The PRM produces reluctance torque and torque by permanent magnet (PM) flux. The reluctance torque is 1 to 2 times larger than the PM torque. When the PRM operates over a constant-power speed range, the field component of the current will be regulated to maintain a constant voltage. The output power of the developed PRM is 8 to 250kW. It is clarified that the PRM operates at a wide variable-speed range (1:5) with high efficiency (92-97%). It is concluded that the PRM has high performance over a wide constant-power speed range. In addition, the PRM is constructed using a small PM, so that we can solve the problem of cost. Thus, the PRM is a superior machine that is suited for variable-speed drive applications.
Method for emulation of synchronous machine
2011-01-01
The present invention relates to electric energy sources, such as a single wind power turbine or wind power plant, that are interfaced with the utility grid through power electronic converters. In particular, the present invention relates to specific techniques and methodologies for power electro...
Cogging torque reduction for interior permanent magnet synchronous motors
Tost Candel, Miquel
2015-01-01
Interior permanent magnet synchronous machines show a good range of behaviours, which make these kinds of machines good candidates for an electromechanical energy conversion. However, in order to improve their accuracy in their torque responses, the cogging torque and torque ripple phenomena should be mitigated to obtain better performance of the machine. In order to reduce the cogging torque and torque ripple, control techniques as well as geometric parameters of the machine have to be im...
刘朝华; 李小花; 张红强; 周少武
2015-01-01
为提高永磁同步电机(Permanent magnet synchronous machine,PMSM)系统参数辨识与状态监测效率,利用图形处理器(Graphics processing unit,GPU)并行计算与人工免疫技术相结合的研究方法,建立面向永磁同步电机系统基于GPU并行动态学习型免疫进化的参数估计与状态监测模型.为提高算法的动态跟踪性能,在抗体演化进程中,通过知识学习策略来引导算法进化过程,首先将抗体群划分为B细胞群、浆细胞群以及记忆细胞群,对处于不同进化群体中的抗体分别设计免疫综合学习策略、免疫反向学习策略和高斯学习策略,以增强抗体间的信息交互;接着,应用图形处理器并行计算技术进一步加速算法求解过程;最后,将所提算法应用于永磁同步电机系统参数辨识与状态监测中,实验表明,所提方法能同时准确地对电机的定子电阻、dq轴电感和永磁磁链等系统关键参数进行估计.依据参数变化实现对系统运行状态进行在线监测与预警.计算结果表明,GPU并行技术能大幅度提高计算效率.
Xiao-yan HUANG; Jian-cheng ZHANG; Chuan-ming SUN; Zhang-wen HUANG; Qin-fen LU; You-tong FANG; Li YAO
2015-01-01
This paper presents a combined dynamic parameter model (DPM) of a high speed train permanent magnet traction system using a dynamic reluctance mesh model and MATLAB Simulink. First, the dynamic reluctance model of the permanent magnet synchronous motor is introduced. Then the combined models of the traction system underid=0 and maximum torque per ampere control are built.Simulations using both constant parameter models and DPM models are carried out. The speed and torque characteristics are obtained. The results confirm that the DPM model provides higher accuracy without much sacrifice of time consumption or computation resource.%目的：提出基于动态磁网络和Simulink的高速铁路牵引传动系统的动态参数模型，提高高速铁路牵引传动系统仿真分析的准确度。 方法：将动态磁网络计算得出的动态参数Ld，Lq等以查表的形式嵌入 Simulink 模型，有效地实现动态参数。 结论：该动态参数模型能在不显著增加仿真运算量和仿真时间的条件下有效地提高计算的准确度。
Design and Performance Improvement of AC Machines Sharing a Common Stator
Guo, Lusu
With the increasing demand on electric motors in various industrial applications, especially electric powered vehicles (electric cars, more electric aircrafts and future electric ships and submarines), both synchronous reluctance machines (SynRMs) and interior permanent magnet (IPM) machines are recognized as good candidates for high performance variable speed applications. Developing a single stator design which can be used for both SynRM and IPM motors is a good way to reduce manufacturing and maintenance cost. SynRM can be used as a low cost solution for many electric driving applications and IPM machines can be used in power density crucial circumstances or work as generators to meet the increasing demand for electrical power on board. In this research, SynRM and IPM machines are designed sharing a common stator structure. The prototype motors are designed with the aid of finite element analysis (FEA). Machine performances with different stator slot and rotor pole numbers are compared by FEA. An 18-slot, 4-pole structure is selected based on the comparison for this prototype design. Sometimes, torque pulsation is the major drawback of permanent magnet synchronous machines. There are several sources of torque pulsations, such as back-EMF distortion, inductance variation and cogging torque due to presence of permanent magnets. To reduce torque pulsations in permanent magnet machines, all the efforts can be classified into two categories: one is from the design stage, the structure of permanent magnet machines can be optimized with the aid of finite element analysis. The other category of reducing torque pulsation is after the permanent magnet machine has been manufactured or the machine structure cannot be changed because of other reasons. The currents fed into the permanent magnet machine can be controlled to follow a certain profile which will make the machine generate a smoother torque waveform. Torque pulsation reduction methods in both categories will be
Mapping Scrambled Korean Sentences into English Using Synchronous TAGs
Park, H S
1995-01-01
Synchronous Tree Adjoining Grammars can be used for Machine Translation. However, translating a free order language such as Korean to English is complicated. I present a mechanism to translate scrambled Korean sentences into English by combining the concepts of Multi-Component TAGs (MC-TAGs) and Synchronous TAGs (STAGs).
Permutation parity machines for neural cryptography.
Reyes, Oscar Mauricio; Zimmermann, Karl-Heinz
2010-06-01
Recently, synchronization was proved for permutation parity machines, multilayer feed-forward neural networks proposed as a binary variant of the tree parity machines. This ability was already used in the case of tree parity machines to introduce a key-exchange protocol. In this paper, a protocol based on permutation parity machines is proposed and its performance against common attacks (simple, geometric, majority and genetic) is studied.
Position Control of Switched Reluctance Motor Using Super Twisting Algorithm
Muhammad Rafiq Mufti
2016-01-01
Full Text Available The inherent problem of chattering in traditional sliding mode control is harmful for practical application of control system. This paper pays a considerable attention to a chattering-free control method, that is, higher-order sliding mode (super twisting algorithm. The design of a position controller for switched reluctance motor is presented and its stability is assured using Lyapunov stability theorem. In order to highlight the advantages of higher-order sliding mode controller (HOSMC, a classical first-order sliding mode controller (FOSMC is also applied to the same system and compared. The simulation results reflect the effectiveness of the proposed technique.
Reluctant altruism and peer pressure in charitable giving
Diane Reyniers
2013-01-01
Full Text Available Subjects donate individually (control group or in pairs (treatment group. Those in pairs reveal their donation decision to each other. Average donations in the treatment group are significantly higher than in the control group. Paired subjects have the opportunity to revise their donation decision after discussion. Pair members shift toward each others' initial decisions. Subjects are happier with their decision when their donations are larger, but those in pairs are less happy, controlling for amount donated. These findings suggest reluctant altruism due to peer pressure in charitable giving.
A Novel Single Phase Hybrid Switched Reluctance Motor Drive System
Liang, Jianing; Xu, Guoqing; Jian, Linni
2011-01-01
In this paper, a novel single phase hybrid switched reluctance motor(SRM) drive system is proposed. It integrated a single phase hybrid SRM and a novel single phase boost converter. This motor can reduce the number of phase switch. And the permanent magnet which is used in the motor can improve t...... SRM reduce the negative torque before zero-crossing point of torque curve, and build desired phase current to generate more power. Some experimental results are done to verify the performance of proposed hybrid SRM drive system....
Petroleum staff reluctance and adjustment to innovative changes
Makasheva, Yu S.; Makasheva, N. P.; Remnyakov, V. V.; Burykhin, B. S.; Shenderova, I. V.
2015-11-01
The modern economy is developing in the direction of innovations implementation. Innovations are becoming the basic prerequisite for the competitiveness of the enterprises. The Russian oil and gas sector innovation issue is very crucial. Low innovation activity of companies could result in a serious threat due to the strong global competition, increased uncertainty and risks. The need for innovative changes often meets reluctance. The reasons of it vary and require serious research. Managers should give special attention to the development of adjustment ability of the staff, to introduce modern methods for improving the adjustment potential of the enterprise staff.
无
2001-01-01
Multi-motor vibratory transmission systems have been wide used in large vibratory machines, and four-motor linear vibratory machine is one typical equipment of them. Under non-forcible synchronization condition zero-phase synchronization of the machine is non-stationary and π-phase synchronization is stable. Under half-forcible synchronization condition in which only one motor is controlled being synchronous to another, only lag synchronization near zero-phase synchronization can be realized. Both of the characteristics have never been revealed with classical theory quantitatively. The problem is solved by means of establishing an electromechanical coupling mathematical model of the system and numerical analysis of the starting processes.
When Machines Design Machines!
2011-01-01
Until recently we were the sole designers, alone in the driving seat making all the decisions. But, we have created a world of complexity way beyond human ability to understand, control, and govern. Machines now do more trades than humans on stock markets, they control our power, water, gas...... and food supplies, manage our elevators, microclimates, automobiles and transport systems, and manufacture almost everything. It should come as no surprise that machines are now designing machines. The chips that power our computers and mobile phones, the robots and commercial processing plants on which we...... depend, all are now largely designed by machines. So what of us - will be totally usurped, or are we looking at a new symbiosis with human and artificial intelligences combined to realise the best outcomes possible. In most respects we have no choice! Human abilities alone cannot solve any of the major...
Dynamical system synchronization
Luo, Albert C J
2013-01-01
Dynamical System Synchronization (DSS) meticulously presents for the first time the theory of dynamical systems synchronization based on the local singularity theory of discontinuous dynamical systems. The book details the sufficient and necessary conditions for dynamical systems synchronizations, through extensive mathematical expression. Techniques for engineering implementation of DSS are clearly presented compared with the existing techniques. This book also: Presents novel concepts and methods for dynamical system synchronization Extends beyond the Lyapunov theory for dynamical system synchronization Introduces companion and synchronization of discrete dynamical systems Includes local singularity theory for discontinuous dynamical systems Covers the invariant domains of synchronization Features more than 75 illustrations Dynamical System Synchronization is an ideal book for those interested in better understanding new concepts and methodology for dynamical system synchronization, local singularity...
Systems and methods for self-synchronized digital sampling
Samson, Jr., John R. (Inventor)
2008-01-01
Systems and methods for self-synchronized data sampling are provided. In one embodiment, a system for capturing synchronous data samples is provided. The system includes an analog to digital converter adapted to capture signals from one or more sensors and convert the signals into a stream of digital data samples at a sampling frequency determined by a sampling control signal; and a synchronizer coupled to the analog to digital converter and adapted to receive a rotational frequency signal from a rotating machine, wherein the synchronizer is further adapted to generate the sampling control signal, and wherein the sampling control signal is based on the rotational frequency signal.
Time Optimal Synchronization Procedure and Associated Feedback Loops
Angoletta, Maria Elena; CERN. Geneva. ATS Department
2016-01-01
A procedure to increase the speed of currently used synchronization loops in a synchrotron by an order of magnitude is presented. Beams dynamics constraint imposes an upper limit on excursions in stable phase angle, and the procedure presented exploits this limit to arrive in the synchronized state from an arbitrary initial state in the fastest possible way. Detailed corrector design for beam phase loop, differential frequency loop and final synchronization loop is also presented. Finally, an overview of the synchronization methods currently deployed in some other CERN’s machines is provided, together with a brief comparison with the newly proposed time-optimal algorithm.
Smooth torque speed characteristic of switched reluctance motors
Zeng, Hui; Chen, Zhe; Chen, Hao
2014-01-01
of the constraints of the supply voltage and peak current. Based on previous work that sought to expand the STO range, a scheme is developed in this study to determine the maximum smooth torque range at each speed. The relationship between the maximum smooth torque and speed is defined as the smooth torque speed......The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because...... characteristics (STSC), a concept similar to torque speed characteristics (TSC). STSC can be utilized to evaluate torque utilization by comparing it with TSC. Thus, the concept benefits the special design of SRMs, especially for the generation of smooth torque. Furthermore, the torque sharing function (TSF...
Adaptive neuro-fuzzy controller of switched reluctance motor
Tahour Ahmed
2007-01-01
Full Text Available This paper presents an application of adaptive neuro-fuzzy (ANFIS control for switched reluctance motor (SRM speed. The ANFIS has the advantages of expert knowledge of the fuzzy inference system and the learning capability of neural networks. An adaptive neuro-fuzzy controller of the motor speed is then designed and simulated. Digital simulation results show that the designed ANFIS speed controller realizes a good dynamic behaviour of the motor, a perfect speed tracking with no overshoot and a good rejection of impact loads disturbance. The results of applying the adaptive neuro-fuzzy controller to a SRM give better performance and high robustness than those obtained by the application of a conventional controller (PI.
Finite element analysis and performance study of switched reluctance generator
Zhang, Qianhan; Guo, Yingjun; Xu, Qi; Yu, Xiaoying; Guo, Yajie
2017-03-01
Analyses a three-phase 12/8 switched reluctance generator (SRG) which is based on its structure and performance principle. The initial size data were calculated by MathCAD, and the simulation model was set up in the ANSOFT software environment with the maximum efficiency and the maximum output power as the main reference parameters. The outer diameter of the stator and the inner diameter of the rotor were parameterized. The static magnetic field distribution, magnetic flux, magnetic energy, torque, inductance characteristics, back electromotive force and phase current waveform of SRG is obtained by analyzing the static magnetic field and the steady state motion of two-dimensional transient magnetic field in ANSOFT environment. Finally, the experimental data of the prototype are compared with the simulation results, which provide a reliable basis for the design and research of SRG wind turbine system.
Hysteresis Current Control of Switched Reluctance Motor in Aircraft Applications
Maged N. F. Nashed
2014-05-01
Full Text Available The switched reluctance motor (SRM drives have been widely used in aircraft applications due to the motor advantages like high speed operation, simple construction, no windings on rotor. But high torque ripples and acoustic noise are main disadvantages. The current hysteresis chopping control is one of the important control methods for SRM drives. These disadvantages can be limited using the hysteresis or chopping current control. This control strategy makes the torque of SRM maintained within a set of hysteresis bands by applying suitable source voltage. This paper introduces two hysteresis control modes; hard chopping and soft chopping mode. The SRM drive system is modeled in Simulink model using MATLAB/SIMULINK software package.
Development of a Switched Reluctance Motor made of Permendur
Hasegawa, Y.; Nakamura, K.; Ichinokura, O.
2011-01-01
A switched reluctance (SR) motor consists of stator and rotor cores, and windings. Both the stator and rotor have salient poles. The stator has concentrated windings on each salient pole. On the other hand, the rotor has no windings and no permanent magnets. Therefore, the SR motor is a low cost, extremely robust, and wide-range variable-speed motor. The performance of the SR motor greatly depends on magnetic properties of core material since it consists of only iron cores and windings. This paper presents the development of a novel SR motor made of permendur which has extremely high saturation flux density and very low core loss. Two types of SR motors, one is made of conventional non-oriented Si steel, the other is made of permendur, are compared by simulation and experiment. It is demonstrated that the torque of the SR motor made of permendur is greater than that of the conventional Si steel by 20%.
Coil Optimization for High Temperature Superconductor Machines
Mijatovic, Nenad; Jensen, Bogi Bech; Abrahamsen, Asger Bech
2011-01-01
This paper presents topology optimization of HTS racetrack coils for large HTS synchronous machines. The topology optimization is used to acquire optimal coil designs for the excitation system of 3 T HTS machines. Several tapes are evaluated and the optimization results are discussed. The optimiz...
CHARACTERISTICS OF A 4-PHASE VALVE RELUCTANCE MOTOR WHEN POWERED BY UNCAPACITOR SWITCHBOARD
V.B. Finkelshtein
2016-06-01
Full Text Available Purpose. Nowadays more and more in a variety of machines and mechanisms applied switched reluctance motor. When designing these engines solve the problem selection switch. While the switch scheme comprises symmetrical bridge and eight transistors, eight diodes; Miller switch comprises six transistors and six diodes; in company Graseby Controls Ltd switch circuit but four transistors and four diodes includes two capacitors. The aim is to develop a mathematical model, calculation program, a numerical analysis of the characteristics and parameters of the WFD and the characteristics of their work. Methodology. It is assumed that the resistance in the open state transistors and diodes for direct current is zero and the resistance of the transistors in the closed state, and diode reverse voltage is infinity. When feeding a single-phase motor and power at the same time two adjacent phases determined by the flow through the tooth. Results. The motor powered by a switch on the circuit symmetrical bridge power, which provides a maximum permissible winding temperature is 1.665 kW. But at the same time the surge up to 38.8%, resulting in high levels of noise and vibration. Through the installation of switching angles, ensuring reduction of torque ripple and reduce engine power to a level below which there is a decrease in the value of torque ripple, received power of 1,066 kW and a torque ripple value of 21.18 %. For engines with improved vibration acoustic characteristics necessary to use a switch of four transistors and four diodes. Practical value. For motors with improved vibration acoustic characteristics appropriate to apply uncapacitor switch on four transistors and four diodes, which allows you to receive half the value of torque ripple than the lowest value of the motor torque ripple, eating from a switch on the circuit asymmetric bridge. The cost of reluctance motor with uncapacitor switch on the circuit with four transistors and four diodes is
Complete Study of the Phase Advancing in the Switched Reluctance Motor/Standalone Generator
Majid Asgar
2014-12-01
Full Text Available The switched reluctance motor is a singly excited, doubly salient machine which can be used in the generation mode by selecting the proper firing angles of the phases. Due to its robustness, it has the potential and the ability to become one of the generators to be used in the harsh environment. This paper briefly discusses the energy conversion by a switched reluctance generator (SRG when two switches per phase converter circuit and discrete position sensors are employed. It is well known fact that, as the generator’s speed increases by a prime mover and the shape of the current waveform changes in such a way that limits the production of generating voltage. At high speeds, it is possible for the phase current never reaches the desired value to produce enough back-EMF for sufficient voltage generation, therefore, the output power falls off. In order to remedy this problem, the phase turn on angle is advanced in a way that the phase commutation begins sooner. Since one of the advantages of this type of generator is its variable speed then, the amount of advancing for the turn on angle should be accomplished automatically to obtain the desired output voltage according to the speed of the generator, meaning, as the generator speed increases so should the turn on angle and vice versa. In this respect, this paper introduces an electronic circuit in conjunction with time reshaping of the command pulses obtained from position sensors and the drive converter to achieve this task for a desired output voltage when a SRG feeding a resistive load. To evaluate the generator performance, two types of analysis, namely numerical technique and experimental studies have been utilized on a 6 by 4, 30 V, SRG. In the numerical analysis, due to the highly non-linear nature of the motor, a three dimensional finite element analysis is employed to calculate some of motor parameters and then using these parameter, current shape and magnitude are computed, whereas in
Regulation and controlled synchronization
Huijberts, H.J.C.; Huijberts, H.J.C.; Nijmeijer, Henk; Willems, R.M.A.
1998-01-01
We investigate the problem of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous transmitter dynamics and controlled receiver dynamics. The question is to find a (output) feedback controller that achieves matching between transmitter and
Inverse anticipating chaos synchronization.
Shahverdiev, E M; Sivaprakasam, S; Shore, K A
2002-07-01
We derive conditions for achieving inverse anticipating synchronization where a driven time-delay chaotic system synchronizes to the inverse future state of the driver. The significance of inverse anticipating chaos in delineating synchronization regimes in time-delay systems is elucidated. The concept is extended to cascaded time-delay systems.
Cluster Synchronization Algorithms
Xia, Weiguo; Cao, Ming
2010-01-01
This paper presents two approaches to achieving cluster synchronization in dynamical multi-agent systems. In contrast to the widely studied synchronization behavior, where all the coupled agents converge to the same value asymptotically, in the cluster synchronization problem studied in this paper,
磁悬浮开关磁阻球体电机的数学模型及其仿真%Spherical switched reluctance motor with magnetic levitation
戴敏; 曾励
2011-01-01
针对双绕组无轴承开关磁阻电机的绕组结构复杂、绝缘程度要求高及加工成本高的缺陷,结合悬浮原理和磁阻最小原理,提出一种磁悬浮开关磁阻球体电机.分析了磁悬浮开关磁阻球体电机的基本组成和运行机理,采用磁路分割法对各部分磁路进行推导与计算,建立了球体电机的数学模型.利用Matalab/simunik软件进行仿真,结果表明电机能够实现动子快速稳定悬浮和旋转,并且具有良好的抗干扰性能.%In view of the bearingless switched reluctance motor with double windings, which has a complicated structure, an absolute insulation, and expensive manufacture cost, the paper presents a spherical switched reluctance motor with magnetic levitation on the basis of suspension theory and minimum reluctance principle. It analyses elements and machanism of the spherical switched reluctance motor with magnetic levitation, deduces and calculates the magnetic conduction of the gap by means of the magnetic segmentation. It obtaines a model building of spherical electric machines.With the Matalab／simunik model, simulation results show that the rotor realizes quick stable suspension and rotation, it has excellent anti-jamming performance as well.
Synchronization of chaotic systems.
Pecora, Louis M; Carroll, Thomas L
2015-09-01
We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators.
Synchronization of chaotic systems
Pecora, Louis M.; Carroll, Thomas L. [U.S. Naval Research Laboratory, Washington, District of Columbia 20375 (United States)
2015-09-15
We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators.
An illusion of control modulates the reluctance to tempt fate
Chloe L. Swirsky
2011-10-01
Full Text Available The tempting fate effect is that the probability of a fateful outcome is deemed higher following an action that ``tempts'' the outcome than in the absence of such an action. In this paper we evaluate the hypothesis that the effect is due to an illusion of control induced by a causal framing of the situation. Causal frames require that the action make a difference to an outcome and that the action precedes the outcome. If an illusion of control modulates the reluctance to tempt fate, then actions that make a difference to well-being and that occur prior to the outcome should tempt fate most strongly. In Experiments 1--3 we varied whether the action makes a difference and the temporal order of action and outcome. In Experiment 4 we tested whether an action can tempt fate if all outcomes are negative. The results of all four experiments supported our hypothesis that the tempting fate effect depends on a causal construal that gives rise to a false sense of control.
许晓宇; 赵晓慈
2016-01-01
为减小工件装夹变形，提高薄壁件加工精度，以薄壁零件装夹变形最小化为目标函数，通过遗传算法和有限元方法相结合，提出夹紧顺序、装夹布局和夹紧力同步分析方法。用该方法对一航空薄壁零件装夹进行优化分析，优化结果与经验设计及传统分析结果进行对比，有效地降低了工件因装夹不当引起的变形，验证了夹紧顺序、夹具布局和夹紧力同步优化方法的有效性。%In order to minimize the clamping deformation and improve the machining accuracy of thin-walled parts, a synchronous optimization method of clamping sequences, fixture layout and clamping forces was presented with the objective function of minimizing the deformation and through the combination of genetic algorithm and finite element method. An aviation thin-walled work piece was optimized by this method, and compared the optimization results with the experience empirical design and the traditional analysis results. This method can effectively reduce the work piece deformation due to improper clamping and improve the machining accuracy. The result proved the veracity of the synchronous optimization method of clamping sequences, fixture layout and clamping forces.
Determination and analysis of synchronous motor's parameters
Mesņajevs, Aleksandrs; Zviedris, Andrejs
2009-01-01
In this work the parameters of synchronous machines are analyzed- direct-axis reaction Xad and quadrature-axis reaction Xaq. Methods of calculation in view of magnetic system's and its element's saturation are presented. It is shown that definition of these reactances, using as a basis a two-reaction method, is not correct and connected with work demanding chart analyzing calculations. The new approach to the qualitative and quantitative analysis of synchronous machine's operating modes which is based on consecutive use of the magnetic field's theory is offered, without it with two-reaction parameters Xad and Xaq. This approach is realized by means of a magnetic field's modeling using numerical methods with help of modern computers.
Interlanguages and synchronic models of computation
Berka, Alexander Victor
2010-01-01
A novel language system has given rise to promising alternatives to standard formal and processor network models of computation. An interstring linked with a abstract machine environment, shares sub-expressions, transfers data, and spatially allocates resources for the parallel evaluation of dataflow. Formal models called the a-Ram family are introduced, designed to support interstring programming languages (interlanguages). Distinct from dataflow, graph rewriting, and FPGA models, a-Ram instructions are bit level and execute in situ. They support sequential and parallel languages without the space/time overheads associated with the Turing Machine and l-calculus, enabling massive programs to be simulated. The devices of one a-Ram model, called the Synchronic A-Ram, are fully connected and simpler than FPGA LUT's. A compiler for an interlanguage called Space, has been developed for the Synchronic A-Ram. Space is MIMD. strictly typed, and deterministic. Barring memory allocation and compilation, modules are ref...
A novel excitation assistance switched reluctance wind power generator
Liu, Xiao; Park, Kiwoo; Chen, Zhe
2014-01-01
finite element analysis. The prototype of the proposed EASRG is built and the preliminary measurement of the inductance was done. The relative big difference between the measured and calculated result of the maximum inductance may be caused by the machining error of the air-gap. The prototype would...
2012-01-01
Topside Variable Speed Drive (VSD) feeding a subsea load via a long cable is not a new technological challenge and many features in systems feeding asynchronous machines are well known. For a synchronous machine the situation is different as a net positive machine torque is not guaranteed. Therefor an analysis of the start sequence of such machine is of interest. In this work starting of a Permanent Magnet Synchronous Machine (PMSM) powered by a VSD via a long subsea cable have been studi...
Ali Asghar Memon
2013-04-01
Full Text Available This paper presents a gate driver circuit for the switching devices used in the asymmetrical converter for a switched reluctance machine with reduced number of isolated dc/dc converters. Isolation required in the gate driver circuit of switching devices is indispensable. For the purpose of isolation different arrangements may be used such as pulse transformers. The dc/dc converter for isolation and powering the gate drive circuits is suitable, cheaper in cost and simple to implement. It is also significant that required number of isolation converters is much less than the switches used in converter. In addition, a simple logic circuit has been presented for producing the gate signals at correct phase sequence which is compared with the gated signals directly obtained from the encoder of an existing machine.
Fine synchronization of the muon drift tubes local trigger
Aldaya, M; Bellato, Marco; Bontenackels, Michael; Castellani, Lorenzo; Cavallo, Francesca Romana; Cerminara, Gianluca; Conti, Enrico; de la Cruz, Begona; Dal Corso, Flavio; Dallavalle, Gaetano-Marco; Fernández, C; Fernández de Troconiz, J; Fouz-Iglesias, M C; Giunta, Marina; Gonella, Franco; Guiducci, Luigi; Höpfner, K; Jimenez, Ignacio; Josa-Mutuberria, I; Marcellini, Stefano; Maron, Gaetano; Meneguzzo, Anna Teresa; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Parenti, Andrea; Passaseo, Marina; Pegoraro, Matteo; Perrotta, Andrea; Puerta, J; Reithler, Hans; Ronchese, Paolo; Rovelli, Tiziano; Ruetten, P; Sowa, Michael; Toniolo, Nicola; Travaglini, Riccardo; Vanini, Sara; Ventura, Sandro; Villanueva, C; Zanetti, Marco; Zotto, Pierluigi
2006-01-01
The CMS muon trigger, based on self-triggering arrays of drift tubes, is able to perform the identification of the muon parent bunch crossing using a rather sophisticated algorithm. The identification is unique only if the trigger chain is correctly synchronized. Some test beam time was devoted to take data useful to investigate the solutions to the problem of the synchronization of the trigger electronics with the machine clock. Possible alternatives were verified and dependence on muon track properties were studied.
全自动罗拉车系统中的同步跟随控制研究%Study on Synchronous Follow Control in Automatic Rola Machine System
王体泮
2014-01-01
为了解决目前罗拉车在线缝过程中针距不均匀、倒缝冲击大等问题，分析全自动罗拉车在缝纫过程中上、下滚轮、摆针轴及主轴的运动关系，建立控制模型，并根据这4轴同步运动数据计算跟随参数。目前，该方法已经完整地在实际项目中进行了应用，取得了很好的线缝效果。%In order to resolve the problems which are produced during line sewing such as stitch asymmetry and exquisite backstitch impacting, the paper analyses the relationships among the top idlewheel and the bottom idlewheel and the swing needle axis and the spindle, sets up the controller mode, and calculates the synchronous parameters through 4 axis synchronous motion data. Now the method is already used in fact and attains the good performance in line sewing.
Mestre, Tiago A; Teodoro, Tiago; Reginold, William; Graf, Julia; Kasten, Maike; Sale, Joanna; Zurowski, Mateusz; Miyasaki, Janis; Ferreira, Joaquim J; Marras, Connie
2014-06-01
Reluctance to start medication has never been investigated before in PD. We studied reluctance to start medication for PD motor symptoms, namely its prevalence, underlying reasons, drug-specificity, and associated delay in the start of PD medication. A cross-sectional observational international study was conducted. Patients with a clinical diagnosis of PD advised to start antiparkinsonian medication in the previous 5 years were invited to complete a questionnaire in three centers located in North America and Europe. An electronic online survey was sent to physicians through the mailing list of the Movement Disorder Society. 469 participants (201 PD patients, 268 physicians). 40.2% (n = 82) of the patients reported reluctance to start medication, but 88.6% (n = 234/264) of the physicians estimated that ≤20% of their patients with PD had been reluctant to start medication. The most common reasons reported by patients were the fear of side effects (n = 35, 55.6%), followed by non-acceptance of diagnosis (n = 23, 36.5%); fear of a temporally limited benefit was more commonly selected by physicians (n = 92/267, 34.5%). Patients indicated reluctance to start DAs more frequently compared with L-DOPA (OR: 2.22, 95% CI: 1.30, 9.03; p = 0.013) while physicians perceived L-DOPA to be associated with more reluctance (OR: 4.7, 95% CI: 3.41; 6.59; p < 0.0001). Patients with PD and physicians have a different perspective on the issue of reluctance to start medication. There is a need to bring physicians and patients with PD closer to a shared vision of the problem reluctance to start medication. Copyright © 2014. Published by Elsevier Ltd.
Nonlinear state space model identification of synchronous generators
Dehghani, M.; Nikravesh, S.K.Y. [Electrical Engineering Department, Amirkabir University of Technology, Tehran (Iran)
2008-05-15
A method for identification of a synchronous generator is suggested in this paper. The method uses the theoretical relations of machine parameters and the Prony method to find the state space model of the system. Such models are useful for controller design and stability tests. The proposed identification method is applied to a third order model of a synchronous generator. In this study, the field voltage is considered as the input and the active output power and the rotor angle are considered as the outputs of the synchronous generator. Simulation results show good accuracy of the identified model. (author)
张严心
2015-01-01
As a kind of ancillary translation tool, Machine Translation has been paid increasing attention to and received different kinds of study by a great deal of researchers and scholars for a long time. To know the definition of Machine Translation and to analyse its benefits and problems are significant for translators in order to make good use of Machine Translation, and helpful to develop and consummate Machine Translation Systems in the future.
Development of Virtual Simulation System for Remote Collaborative Surface Machining
R.S.Lee; Y.S.Lin; Y.C.Kao; C. H. She
2006-01-01
Most researches about virtual machine tool are emphasized on simulations of machine motion and machining process for single machine. In this paper, a virtual simulation system for remote collaborative surface machining is developed. The motion command of machine tool is generated by an interpolator, which can derive synchronized motion commands according to feedrate. Thus, the system can estimate the machining time. For universal assembly of five-axis virtual machine tool, it is based on the D-H notation representation and machining constraints consideration. The remote collaborative virtual manufacturing system based on the CORBA technology is proposed in this paper. It demonstrated that the developed virtual machine tool can be used to verify and simulate the machining process for the collaboration of the surface design and manufacturing team.
2017-01-01
This book provides an overview on current sustainable machining. Its chapters cover the concept in economic, social and environmental dimensions. It provides the reader with proper ways to handle several pollutants produced during the machining process. The book is useful on both undergraduate and postgraduate levels and it is of interest to all those working with manufacturing and machining technology.
Damping torque analysis of VSC-based system utilizing power synchronization control
Fu, Q.; Du, W. J.; Zheng, K. Y.; Wang, H. F.
2017-05-01
Power synchronization control is a new control strategy of VSC-HVDC for connecting a weak power system. Different from the vector control method, this control method utilizes the internal synchronization mechanism in ac systems, in principle, similar to the operation of a synchronous machine. So that the parameters of controllers in power synchronization control will change the electromechanical oscillation modes and make an impact on the transient stability of power system. This paper present a mathematical model for small-signal stability analysis of VSC station used power synchronization control and analyse the impact of the dynamic interactions by calculating the contribution of the damping torque from the power synchronization control, besides, the parameters of controllers which correspond to damping torque and synchronous torque in the power synchronization control is defined respectively. At the end of the paper, an example power system is presented to demonstrate and validate the theoretical analysis and associated conclusions are made.
R E Amritkar
2008-08-01
We study the synchronization of coupled dynamical systems on networks. The dynamics is governed by a local nonlinear oscillator for each node of the network and interactions connecting different nodes via the links of the network. We consider existence and stability conditions for both single- and multi-cluster synchronization. For networks with time-varying topology we compare the synchronization properties of these networks with the corresponding time-average network. We find that if the different coupling matrices corresponding to the time-varying networks commute with each other then the stability of the synchronized state for both the time-varying and the time-average topologies are approximately the same. On the other hand, for non-commuting coupling matrices the stability of the synchronized state for the time-varying topology is in general better than the time-average topology.
Agarlita, Sorin-Christian; Fatu, M.; Tutelea, L. N.
2010-01-01
based sensorless vector control and vice versa when the frequency reaches a certain level. The control also integrates a state observer based on the active “flux concept” used to deliver RSM rotor position and speed information. Experimental results validate the proposed control strategies....
Design and Advanced Control of Switched Reluctance Motors
Rasmussen, Peter Omand
with SR technology is the reputation of the high acoustic noise emission compared to other electrical machines. Therefore, extra focus to analyze this specific subject is done. The major origin to the high level of acoustic noise is due to highly concentrated normal forces with a high harmonic content...... with the control strategy and the output is the sound pressure at the top of the stator yoke. This is presented as both a technical A-weighted value and as a subjective value in form of the sound from the PC having the SRDaS program installed. The developed acoustic models are also verified in practice on several...
The Role of Synchronization in Perception-Action
Chan, Tin-Cheung; Yue, Xiaomin; Shi, Zhuanghua; Hong, Bo
Synchronization between brain areas can be taken as a sign of processes of self-organization modifying the connectivity between brain centers in such a way that they can engage effectively in different tasks. The results of an experiment investigating two issues concerning brain synchronization will be discussed here. First, does synchronization occur automatically, without effort, or through controlled processes? Second, is synchronization maintained or is it transient? In the experiment, eight participants watched two numbers presented on a screen. If the sum of these numbers was odd, participants were asked to press a button corresponding to the geometric figure following the presentation of the numbers, with the stimulus-onset asynchrony (SOA) varied between trials. In case of an even sum, no action was needed. EEG was collected with a 32-channel NeuroScan EEG machine. Analysis was conducted with multivariate autoregressive (MVAR) modeling in order to show coherence between brain areas on a spatio-temporal map. Results suggest that synchronization between perceptual or motor brain areas is automatic. When decisions have to be made, however, latency is affected by the proximity of the tasks, which shows that controlled processes are involved. Results also show that brain synchronization is transient in nature, therefore providing for synchronization patterns to be produced in sequence. It appears that the maintenance of a certain brain state and the related behavior is based on the embodiment of stimulus and task in brain synchronization.
Linear and Planar Variable Reluctance Motors for Flexible Manufactoring Cells
Imre Szepi
2004-01-01
Full Text Available Most advances manufactoring processes require precise linear motion for several tasks as material transfer, packaging, assembly or electrical wiring. To achieve precise linear motion, most of the usual high-performance manufactoring machines use X-Y sliding tables with rotary motors and rotary - to - linear couplers. Though this method is the most widely used, it has disadvantages of low ccuracy, complex mechanical adjustments, hogh cost, and low reliability. This paper describes a novel modular construction which can be used to build up linear surface direct - driven motors for high performance motions in flexible manufactoring automation. The proposed motors have simple modular structure and they have no limitation on the travel distance. Simulated results of the linear and planar motion systems indicate that the motion systems has good accurancy.
Graybill, George
2007-01-01
Just how simple are simple machines? With our ready-to-use resource, they are simple to teach and easy to learn! Chocked full of information and activities, we begin with a look at force, motion and work, and examples of simple machines in daily life are given. With this background, we move on to different kinds of simple machines including: Levers, Inclined Planes, Wedges, Screws, Pulleys, and Wheels and Axles. An exploration of some compound machines follows, such as the can opener. Our resource is a real time-saver as all the reading passages, student activities are provided. Presented in s
Open Loop and Closed Loop Performance of Switched Reluctance Motor with Various Converter Topologies
Malligunta Kiran Kumar
2014-07-01
Full Text Available Switched reluctance motor (SRM is becoming popular because of its simple construction, robustness and low-maintenance. This motor is very useful for high speed applications because no windings are placed on rotor and can also be used for variable speed applications in industries. Converter is one of the important elements in SRM which plays a very crucial role. In this paper various converter topologies for 6/4 switched reluctance motor and Asymmetric bridge converter topology for 8/6 switched reluctance motor are discussed. Finally a closed loop for each converter topology is proposed. The converter topologies are simulated by using MATLAB/SIMULINK. Constant speed is achieved in closed loop control.
Beam Synchronous Timing Systems
Peters, A
2003-01-01
For many beam diagnostics purposes beam synchronous timing systems are needed in addition to the timing systems supplied by the control systems of the different accelerators. The demands and techniques of different accelerator facilities will be discussed along the following aspects: Bunch and macro pulse synchronous timing systems Solutions for different time scales from ps to ms Coupling to the RF and control systems of the different accelerators Electronics for the beam synchronous timing systems: parameters, techniques, controlling Use of industrial products for bunch synchronous timing systems, e.g. function generators Distribution of the timing signals: electronically via cables, optically via fibres or wireless Coupling to and use of timing standards: IRIG-B, GPS, ? The participants should present and describe solutions from their facilities with some transparencies as a starting point for the discussion.
Synchronization of hyperchaotic oscillators
Tamasevicius, A.; Cenys, A.; Mykolaitis, G.
1997-01-01
Synchronization of chaotic oscillators is believed to have promising applications in secure communications. Hyperchaotic systems with multiple positive Lyapunov exponents (LEs) have an advantage over common chaotic systems with only one positive LE. Three different types of hyperchaotic electronic...
Advanced synchronous luminescence system
Vo-Dinh, Tuan
1997-01-01
A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.
Synchronization in complex networks
Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.
2007-12-12
Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.
Synchronizing Strategies under Partial Observability
Larsen, Kim Guldstrand; Laursen, Simon; Srba, Jiri
2014-01-01
been intensively studied for systems that do not provide any information about their configurations. In order to capture more general scenarios, we extend the existing theory of synchronizing words to synchronizing strategies, and study the synchronization, short-synchronization and subset...
Implementation of a DSP-based hybrid sensor for switched reluctance motor converter
Whei-Min Lin; Ching-Ming Hong; Huang-Chen Chien [Department of Electrical Engineering National Sun Yat-Sen University, Kaohsiung 80424, Taiwan, R.O.C. (China); Huang-Chen Chien [Electronic Communication Engineering, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan, R.O.C. (China)
2010-07-01
The Switched Reluctance Motor (SRM) inherits a simple and reliable structure with an economical manufacturing cost. The DC power output supplies the unipolar converter to control the pulses sent to SRM. Thus, the velocity and torque are controllable for various velocity commands, and the SRM is gaining more and more applications on high torque requirement field with constant power. This paper proposes a DSP based hybrid sensor for switched reluctance motor with easy implementation. The current transducer is used to monitor the energized current and proximity sensors for rotor salient. The signals are then fed back to DSP. This design will improve the performance of SRM to operate more smoothly.
Implementation of a DSP-based hybrid sensor for switched reluctance motor converter
Whei-Min Lin, Chih-Ming Hong, Huang -Chen Chien, Huang-Chen Chien
2010-09-01
Full Text Available The Switched Reluctance Motor (SRM inherits a simple and reliable structure with an economical manufacturing cost. The DC power output supplies the unipolar converter to control the pulses sent to SRM. Thus, the velocity and torque are controllable for various velocity commands, and the SRM is gaining more and more applications on high torque requirement field with constant power. This paper proposes a DSP based hybrid sensor for switched reluctance motor with easy implementation. The current transducer is used to monitor the energized current and proximity sensors for rotor salient. The signals are then fed back to DSP. This design will improve the performance of SRM to operate more smoothly.
Acoustic noise simulation for switched reluctance motors with audible output p
Rasmussen, P.O.; Blaabjerg, F.; Pedersen, J.K.; Kjaer, P.C. [Aalborg Univ., Inst. of Energy Technology (Denmark); Miller, T.J.E. [Univ. of Glasgow, SPEED Lab., Dep. of Electronics and Electrical Engineering (United Kingdom)
1999-07-01
Acoustic noise in switched reluctance motors is one of the last problems which have to be solved before a more widespread use will come. In order to design a low noise Switched Reluctance Motor drive, simulation tools are needed, and this paper describes a design programme where acoustic noise of electromagnetic origin can be estimated and even be heard by the motor-designer. The design program is based on a new, simple developed vibrational and acoustic model where the parameters can be calculated based on the geometry of the motor. The vibrational and acoustic model is verified in both time and frequency domain where vibrations and acoustic noise have been considered. (au)
A New Low-Cost Hybrid Switched Reluctance Motor for Adjustable-Speed Pump Applications
Lu, Kaiyuan; Rasmussen, Peter Omand; Watkins, Steve;
2011-01-01
This paper presents a new low-cost hybrid switched reluctance (HSR) motor intended for use in adjustable-speed pump drive systems. The motor is a single-phase motor, driven by a unipolar converter, which uses both the reluctance torque and the permanent magnet interaction torque. Compared...... systems for low-cost applications. Finite-element models are used to analyze and predict the motor's performance. The proposed motor drive system has been fabricated, and its performance has been tested in the laboratory. These experimental results are also presented....
International Electrotechnical Commission. Geneva
1972-01-01
Applies to d.c. machines and to a.c. synchronous and induction machines. The principles can be applied to other types of machines such as rotary converters, a.c. commutator motors and single-phase induction motors for which other methods of determining losses are used.
El-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Reddy, Patel Bhageerath [Madison, WI
2012-07-17
An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.
解红磊; 张为民; 杨勇
2012-01-01
In order to improve the positioning accuracy of the permanent magnet linear synchronous motors (PMLSM), a neural network is adopted to identify and compensate two types of disturbance force represented by thrust ripple and cutting force respectively in this paper. At first, the thrust ripple result from special structure of PMLSM was identified by sampling the no-load current of motor and modifying the phase difference ; then, the mod- el of thrust ripple was built and the parameters of neural network offline were optimized. Also, eliminate the error of model and compensate for the second type of disturbance force with the adaptability and nonlinear function of neural network. A complex controller with three loops and feed forward based on neural network is designed to conquer the disadvantage of pure model and makes full use of the predictable disturbance force. Simulation results verify that this controller can improve the positioning accuracy of PMLSM and its robustness is strong.%为提高永磁直线同步电机（PMLSM）的定位精度,采用神经网络技术对以推力波动和切削力为代表的两类干扰力分别进行辨识和补偿。针对PMLSM固定结构引起的推力波动,利用电机空载电流进行辨识和修正,建立推力波动模型并离线优化神经网络权系数。加工过程中,利用神经网络的自适应和非线性能力修正模型误差并补偿第二类干扰力。设计了基于神经网络的三环控制与速度、电流前馈复合控制器,克服了纯模型适应性差的缺点并充分利用可预测干扰力。仿真结果表明该控制器能够有效提高PMLSM定位精度,鲁棒性强。
Nuthall, P. L.; Old, K. M.
2017-01-01
Purpose: Despite the benefits of early planning for business succession, and plan implementation, many owners/managers fail to act expeditiously. Factors such as a reluctance to accept ageing, a concern over the risks involved and inappropriate objectives may be causative. This research moves towards explaining this reluctance and, consequently,…
Rojas, Sebastián; Diaz-Galarce, Raúl; Jerez-Baraona, Juan Manuel; Quintana-Donoso, Daisy; Moraga-Amaro, Rodrigo; Stehberg, Jimmy
2015-01-01
Reluctance to try novel tastes (neophobia) can be exacerbated in arousing situations, such as when children are under social stress or in rodents, when the new taste is presented in a high arousal context (HA) compared to a low arousal context (LA). The present study aimed at determining whether adrenergic transmission at the Insula regulates the reluctance to try novel tastes induced by arousing contexts. To this end, a combination of systemic and intra-insular manipulations of adrenergic activity was performed before the novel taste (saccharin 0.1%) was presented either in LA or HA contexts in rats. Our results show that systemic adrenergic activity modulates reluctance to try novel tastes. Moreover, intra-insular microinjections of propranolol or norepinephrine (NE) were found to modulate the effects of arousing contexts on reluctance to try novel tastes. Finally, intra-insular propranolol blocked epinephrine-induced increased reluctance, while intra-insular NE blocked oral propranolol-induced decreases in reluctance and increased the reluctance to try novel tastes presented in low arousing contexts. In conclusion, our results suggest that the insula is a critical site for regulating the effects of arousal in the reluctance to try novel tastes via the adrenergic system. PMID:26175672
Sebastián Andrés Rojas
2015-06-01
Full Text Available Reluctance to try novel tastes (neophobia can be exacerbated in arousing situations, such as when children are under social stress or in rodents, when the new taste is presented in a high arousal context (HA compared to a low arousal context (LA. The present study aimed at determining whether adrenergic transmission at the Insula regulates the reluctance to try novel tastes induced by arousing contexts. To this end, a combination of systemic and intra-insular manipulations of adrenergic activity was performed before the novel taste (saccharin 0.1% was presented either in LA or HA contexts in rats. Our results show that systemic adrenergic activity modulates reluctance to try novel tastes. Moreover, intra-insular microinjections of propranolol or norepinephrine were found to modulate the effects of arousing contexts on reluctance to try novel tastes. Finally, intra-insular propranolol blocked epinephrine-induced increased reluctance, while intra-insular norepinephrine blocked oral propranolol-induced decreases in reluctance and increased the reluctance to try novel tastes presented in low arousing contexts. In conclusion, our results suggest that the insula is a critical site for regulating the effects of arousal in the reluctance to try novel tastes via the adrenergic system.
The Machine within the Machine
Katarina Anthony
2014-01-01
Although Virtual Machines are widespread across CERN, you probably won't have heard of them unless you work for an experiment. Virtual machines - known as VMs - allow you to create a separate machine within your own, allowing you to run Linux on your Mac, or Windows on your Linux - whatever combination you need. Using a CERN Virtual Machine, a Linux analysis software runs on a Macbook. When it comes to LHC data, one of the primary issues collaborations face is the diversity of computing environments among collaborators spread across the world. What if an institute cannot run the analysis software because they use different operating systems? "That's where the CernVM project comes in," says Gerardo Ganis, PH-SFT staff member and leader of the CernVM project. "We were able to respond to experimentalists' concerns by providing a virtual machine package that could be used to run experiment software. This way, no matter what hardware they have ...
Synchronicity in predictive modelling: a new view of data assimilation
Duane, G. S.; Tribbia, J. J.; Weiss, J. B.
2006-11-01
The problem of data assimilation can be viewed as one of synchronizing two dynamical systems, one representing "truth" and the other representing "model", with a unidirectional flow of information between the two. Synchronization of truth and model defines a general view of data assimilation, as machine perception, that is reminiscent of the Jung-Pauli notion of synchronicity between matter and mind. The dynamical systems paradigm of the synchronization of a pair of loosely coupled chaotic systems is expected to be useful because quasi-2D geophysical fluid models have been shown to synchronize when only medium-scale modes are coupled. The synchronization approach is equivalent to standard approaches based on least-squares optimization, including Kalman filtering, except in highly non-linear regions of state space where observational noise links regimes with qualitatively different dynamics. The synchronization approach is used to calculate covariance inflation factors from parameters describing the bimodality of a one-dimensional system. The factors agree in overall magnitude with those used in operational practice on an ad hoc basis. The calculation is robust against the introduction of stochastic model error arising from unresolved scales.
Synchronicity in predictive modelling: a new view of data assimilation
G. S. Duane
2006-01-01
Full Text Available The problem of data assimilation can be viewed as one of synchronizing two dynamical systems, one representing "truth" and the other representing "model", with a unidirectional flow of information between the two. Synchronization of truth and model defines a general view of data assimilation, as machine perception, that is reminiscent of the Jung-Pauli notion of synchronicity between matter and mind. The dynamical systems paradigm of the synchronization of a pair of loosely coupled chaotic systems is expected to be useful because quasi-2D geophysical fluid models have been shown to synchronize when only medium-scale modes are coupled. The synchronization approach is equivalent to standard approaches based on least-squares optimization, including Kalman filtering, except in highly non-linear regions of state space where observational noise links regimes with qualitatively different dynamics. The synchronization approach is used to calculate covariance inflation factors from parameters describing the bimodality of a one-dimensional system. The factors agree in overall magnitude with those used in operational practice on an ad hoc basis. The calculation is robust against the introduction of stochastic model error arising from unresolved scales.
Versions of Switched Reluctance Generatior Design at a Constant Stator Configuration
Nikolay Grebennikov
2015-03-01
Full Text Available The investigation of the influence of the number of phases of switched reluctance generator (SRG to the pulse of electromagnetic torque was carried out. The computer model was created. The amplitude of torque ripples reduces to 6 times with increasing of the ripple frequency to 5 times, that is more acceptable in terms of requirements.
Online Statistics Labs in MSW Research Methods Courses: Reducing Reluctance toward Statistics
Elliott, William; Choi, Eunhee; Friedline, Terri
2013-01-01
This article presents results from an evaluation of an online statistics lab as part of a foundations research methods course for master's-level social work students. The article discusses factors that contribute to an environment in social work that fosters attitudes of reluctance toward learning and teaching statistics in research methods…
Modeling of a Switched Reluctance Motor under Stator Winding Fault Condition
Chen, Hao; Han, G.; Yan, Wei
2016-01-01
A new method for modeling stator winding fault with one shorted coil in a switched reluctance motor (SRM) is presented in this paper. The method is based on artificial neural network (ANN), incorporated with a simple analytical model in electromagnetic analysis to estimate the flux...
Mathematical Tasks without Words and Word Problems: Perceptions of Reluctant Problem Solvers
Holbert, Sydney Margaret
2013-01-01
This qualitative research study used a multiple, holistic case study approach (Yin, 2009) to explore the perceptions of reluctant problem solvers related to mathematical tasks without words and word problems. Participants were given a choice of working a mathematical task without words or a word problem during four problem-solving sessions. Data…
"You Play on Them. They're Active." Enhancing the Mathematics Learning of Reluctant Teenage Students
Calder, Nigel; Campbell, Anthony
2015-01-01
This paper reports on a research project that examined the beliefs and attitudes of reluctant 16 to 18-year-old learners when using apps in their numeracy and literacy programmes. In particular, it considers the students' change of attitude towards numeracy learning. The data were consistent that the use of apps in the numeracy programme was…
A Fault Diagnostic Method for Position Sensor of Switched Reluctance Wind Generator
Wang, Chao; Liu, Xiao; Liu, Hui
2016-01-01
Fast and accurate fault diagnosis of the position sensor is of great significance to ensure the reliability as well as sensor fault tolerant operation of the Switched Reluctance Wind Generator (SRWG). This paper presents a fault diagnostic scheme for a SRWG based on the residual between the estim...
Characteristics Analysis of an Excitation Assistance Switched Reluctance Wind Power Generator
Liu, Xiao; Wang, Chao; Chen, Zhe
2015-01-01
In order to fully analyze the characteristics of an excitation assistance switched reluctance generator (EASRG) applied in wind power generation, a static model and a dynamic model are proposed. The static model is based on the 3-D finite-element method (FEM), which can be used to obtain the stat...
Online Statistics Labs in MSW Research Methods Courses: Reducing Reluctance toward Statistics
Elliott, William; Choi, Eunhee; Friedline, Terri
2013-01-01
This article presents results from an evaluation of an online statistics lab as part of a foundations research methods course for master's-level social work students. The article discusses factors that contribute to an environment in social work that fosters attitudes of reluctance toward learning and teaching statistics in research methods…
Single-Phase Hybrid Switched Reluctance Motor for Low-Power Low-Cost Applications
Lu, Kaiyuan; Rasmussen, Peter Omand; Jakobsen, Uffe
2011-01-01
This paper presents a new single-phase, Hybrid Switched Reluctance (HSR) motor for low-cost, low-power, pump or fan drive systems. Its single-phase configuration allows use of a simple converter to reduce the system cost. Cheap ferrite magnets are used and arranged in a special flux concentration...
Simulation of an HTS Synchronous Superconducting Generator
In this work we present a simulation of a synchronous generator with superconducting rotor windings. As many other electrical rotating machines, superconducting generators are exposed to ripple fields that could be produced from a wide variety of sources: short circuit, load change, etc. Unlike...... regular conductors, superconductors, experience high losses when exposed to AC fields. Thus, calculation of such losses is relevant for machine design to avoid quenches and increase performance. Superconducting coated conductors are well known to exhibit nonlinear resistivity, thus making the computation...... of heating losses a cumbersome task. Furthermore, the high aspect ratio of the superconducting materials involved adds a penalty in the time required to perform simulations. The chosen strategy for simulation is as follows: A mechanical torque signal together with an electric load is used to drive the finite...
Simulation of an HTS Synchronous Superconducting Generator
Rodriguez Zermeno, Victor Manuel; Abrahamsen, Asger Bech; Mijatovic, Nenad
2012-01-01
In this work we present a simulation of a synchronous generator with superconducting rotor windings. As many other,electrical rotating machines, superconducting generators are exposed to ripple fields that could be produced from a wide variety of sources: short circuit, load change, mechanical...... torque fluctuations, etc. Unlike regular conductors, superconductors, experience high losses when exposed to AC fields. Thus, calculation of such losses is relevant for machine design to avoid quenches and increase performance. Superconducting coated conductors are well known to exhibit nonlinear...... resistivity, thus making the computation of heating losses a cumbersome task. Furthermore, the high aspect ratio of the superconducting materials involved adds a penalty in the time required to perform simulations. The chosen strategy for simulation is as follows: A mechanical torque signal together...
Korean to English Translation Using Synchronous TAGs
Egedi, D; Park, H S; Joshi, A K; Egedi, Dania; Palmer, Martha; Park, Hyun S.; Joshi, Aravind K.
1994-01-01
It is often argued that accurate machine translation requires reference to contextual knowledge for the correct treatment of linguistic phenomena such as dropped arguments and accurate lexical selection. One of the historical arguments in favor of the interlingua approach has been that, since it revolves around a deep semantic representation, it is better able to handle the types of linguistic phenomena that are seen as requiring a knowledge-based approach. In this paper we present an alternative approach, exemplified by a prototype system for machine translation of English and Korean which is implemented in Synchronous TAGs. This approach is essentially transfer based, and uses semantic feature unification for accurate lexical selection of polysemous verbs. The same semantic features, when combined with a discourse model which stores previously mentioned entities, can also be used for the recovery of topicalized arguments. In this paper we concentrate on the translation of Korean to English.
Equivalence of History and Generator Epsilon-Machines
Travers, Nicholas F
2011-01-01
Epsilon-machines are minimal, unifilar representations of stationary stochastic processes. They were originally defined in the history machine sense---as machines whose states are the equivalence classes of infinite histories with the same probability distribution over futures. In analyzing synchronization, though, an alternative generator definition was given: unifilar edge-label hidden Markov models with probabilistically distinct states. The key difference is that history epsilon-machines are defined by a process, whereas generator epsilon-machines define a process. We show here that these two definitions are equivalent.
Energy conversion loops for flux-switching PM machine analysis
E. Ilhan; T. E. Motoasca; J. J. H. Paulides; Lomonova, E.A.
2012-01-01
Induction and synchronous machines have traditionally been the first choice of automotive manufacturers for electric/hybrid vehicles. However, these conventional machines are not able anymore to meet the increasing demands for a higher energy density due to space limitation in cars. Flux-switching PM (FSPM) machines with their high energy density are very suitable to answer this demand. In this paper, the energy conversion loop technique is implemented on FSPM for the first time. The energy c...
Design and Modeling of a 3 DOF Machine
Marjan Sikandar
2014-01-01
This paper proposes an IT solution to implement a 3DOF machine by using several design patterns. A Degree of Freedom machine is a motion platform synchronized with the simulation game visually displayed. Through this research we have tried to find an optimal way to implement such a robotic machine that is supposed to be used in different virtual prototypes by industrialists. Since the development cost of an actual product often, is too high to test the initial design, many industrialists now-...
On the Optimal Selection of Electrical Machines Fans
Mădălin Costin
2014-09-01
Full Text Available In this paper an analytic relationship for electrical machine fan design has been developed. In the particularly case of salient poles synchronous machine (with salient poles – for electromagnetic field excitation or surface mounded permanent magnet, this approach allowed to express the fan power as a function of machine middle axe air gap. This analytic foundation developed may leads to different optimization criteria as specific active materials or costs. Numerical simulations confirm our approach.
Nondahl, T. A.; Richter, E.
1980-09-01
A design study of two types of single sided (with a passive rail) linear electric machine designs, namely homopolar linear synchronous machines (LSM's) and linear induction machines (LIM's), is described. It is assumed the machines provide tractive effort for several types of light rail vehicles and locomotives. These vehicles are wheel supported and require tractive powers ranging from 200 kW to 3735 kW and top speeds ranging from 112 km/hr to 400 km/hr. All designs are made according to specified magnetic and thermal criteria. The LSM advantages are a higher power factor, much greater restoring forces for track misalignments, and less track heating. The LIM advantages are no need to synchronize the excitation frequency precisely to vehicle speed, simpler machine construction, and a more easily anchored track structure. The relative weights of the two machine types vary with excitation frequency and speed; low frequencies and low speeds favor the LSM.
MACHINE-TRANSFORMER UNITS FOR WIND TURBINES
V.I. Panchenko
2016-03-01
Full Text Available Background. Electric generators of wind turbines must meet the following requirements: they must be multi-pole; to have a minimum size and weight; to be non-contact, but controlled; to ensure the maximum possible output voltage when working on the power supply system. Multipole and contactless are relatively simply realized in the synchronous generator with permanent magnet excitation and synchronous inductor generator with electromagnetic excitation; moreover the first one has a disadvantage that there is no possibility to control the output voltage, and the second one has a low magnetic leakage coefficient with the appropriate consequences. Purpose. To compare machine dimensions and weight of the transformer unit with induction generators and is an opportunity to prove their application for systems with low RMS-growth rotation. Methodology. A new design of the electric inductor machine called in technical literature as machine-transformer unit (MTU is presented. A ratio for estimated capacity determination of such units is obtained. Results. In a specific example it is shown that estimated power of MTU may exceed the same one for traditional synchronous machines at the same dimensions. The MTU design allows placement of stator coil at some distance from the rotating parts of the machine, namely, in a closed container filled with insulating liquid. This will increase capacity by means of more efficient cooling of coil, as well as to increase the output voltage of the MTU as a generator to a level of 35 kV or more. The recommendations on the certain parameters selection of the MTU stator winding are presented. The formulas for copper cost calculating on the MTU field winding and synchronous salient-pole generator are developed. In a specific example it is shown that such costs in synchronous generator exceed 2.5 times the similar ones in the MTU.
Lewy, Jennifer; Cyr, Mireille; Dion, Jacinthe
2015-05-01
In the field of child sexual abuse (CSA) disclosure, many studies have been conducted on the impact of interviewers' questioning style, but few have examined the impact of interviewers' supportive comments on children's cooperative and reluctant disclosure of substantive details. This field study used a sample of children ranging from 4 to 13 years of age who have all disclosed CSA. The first objective was to examine if the interviewer's and the child's comments during CSA interviews would vary as a function of the use of the National Institute of Child Health and Human Development (NICHD) Protocol. The second objective was to identify the strongest correlates of the proportion of details disclosed by the children during forensic interviews. A total of 90 matched NICHD Protocol and non-Protocol interviews done by the same interviewers were audio-taped, transcribed, and coded using verbal subscales. The goal was to explore if differences exist between the interviewers' supportive and non-supportive comments as well as children's cooperative and reluctant statements during investigative interviews conducted prior to or after the NICHD Protocol training. Results of a MANCOVA showed that the use of the NICHD Protocol had no influence on interviewers' and children's demeanors. A hierarchical multiple regression analysis controlling for relevant variables (e.g., child's age and NICHD Protocol) showed that children's reluctance and interviewers' non-support were associated with a lesser proportion of details. Overall, these results indicate that in order to promote detailed disclosure of CSA, interviewers should decrease their non-supportive comments and learn to deal more effectively with children's reluctance during forensic interviews. As such, protocols and training should encourage investigative interviewers to devote more time identifying early signs of children's verbal reluctance and to understand the negative impact of non-supportive comments on the disclosure of
CERN. Geneva
2017-01-01
Machine learning, which builds on ideas in computer science, statistics, and optimization, focuses on developing algorithms to identify patterns and regularities in data, and using these learned patterns to make predictions on new observations. Boosted by its industrial and commercial applications, the field of machine learning is quickly evolving and expanding. Recent advances have seen great success in the realms of computer vision, natural language processing, and broadly in data science. Many of these techniques have already been applied in particle physics, for instance for particle identification, detector monitoring, and the optimization of computer resources. Modern machine learning approaches, such as deep learning, are only just beginning to be applied to the analysis of High Energy Physics data to approach more and more complex problems. These classes will review the framework behind machine learning and discuss recent developments in the field.
Measure Synchronization on Symplectic Map
CHEN Shao-Ying; XU Hai-Bo; WANG Guang-Rui; CHEN Shi-Gang
2004-01-01
Measure synchronization in coupled Hamiltonian systems is a novel synchronization phenomenon. The measure synchronization on symplectic map is observed numerically, for identical coupled systems with different parameters. We have found the properties of the characteristic frequency and the amplitude of phase locking in regular motion when the measure synchronization of coupled systems is obtained. The relations between the change of the largest Lyapunov exponent and the course of phase desynchronization are also discussed in coupled systems, some useful results are obtained. A new approach is proposed for describing the measure synchronization of coupled systems numerically,which is advantage in judging the measure synchronization, especially for the coupled systems in nonregular region.
Synchronization and Inertial Frames
Viazminsky, C P
1999-01-01
In classical mechanics, a procedure for simultaneous synchronization in all inertial frames is consistent with the Galilean transformation. However, if one attempts to achieve such a synchronization utilizing light signals, he will be facing in the first place the break down of simultaneity, and secondly, a self-contradictory transformation that has the Lorentz transformation, or its confinement to the velocity of light, as the only possible ways that resolve the contradiction. The current work constitutes a smooth transition from traditional to relativistic vision of mechanics, and therefore is quite appealing from pedagogical point of view.
Machine learning in medicine cookbook
Cleophas, Ton J
2014-01-01
The amount of data in medical databases doubles every 20 months, and physicians are at a loss to analyze them. Also, traditional methods of data analysis have difficulty to identify outliers and patterns in big data and data with multiple exposure / outcome variables and analysis-rules for surveys and questionnaires, currently common methods of data collection, are, essentially, missing. Obviously, it is time that medical and health professionals mastered their reluctance to use machine learning and the current 100 page cookbook should be helpful to that aim. It covers in a condensed form the subjects reviewed in the 750 page three volume textbook by the same authors, entitled “Machine Learning in Medicine I-III” (ed. by Springer, Heidelberg, Germany, 2013) and was written as a hand-hold presentation and must-read publication. It was written not only to investigators and students in the fields, but also to jaded clinicians new to the methods and lacking time to read the entire textbooks. General purposes ...
Hybrid synchronous motor electromagnetic torque research
Suvorkova Elena E.
2014-01-01
Full Text Available Electromagnetic field distribution models in reluctance and permanent magnet parts were made by means of Elcut. Dependences of electromagnetic torque on torque angle were obtained.
Synchronizing Hyperchaotic Circuits
Tamasevicius, Arunas; Cenys, Antanas; Namajunas, Audrius
1997-01-01
Regarding possible applications to secure communications the technique of synchronizing hyperchaotic circuits with a single dynamical variable is discussed. Several specific examples including the fourth-order circuits with two positive Lyapunov exponents as well as the oscillator with a delay line...... characterized by multiple positive Lyapunov exponents are reviewd....
Synchronization of respiration
Garssen, B.
In order to study synchronization of respiration, three different videofragments were presented to 21 normal subjects. Each fragment showed a ‘therapeutic interview’ specially performed for this purpose, with a ‘patient’ breathing in a particular way. The respiration of model 1 was deep, slow and
开关磁阻风力发电系统研究%Research of switched reluctance wind power generating system
金鑫; 嵇丽丽
2013-01-01
In view of problems of bad stability of wind power generating system based on asynchronous generator,doubly-fed generator and permanent magnet synchronous generator,needing many conditions and being difficult to realize in experimental research of wind power generating system,the paper proposed a research method of wind power generating system based on switched reluctance generator under situation of no experimental condition of wind farm,that is using DC motor to simulate wind generator to make experiment for switched reluctance generating system.It built simulation model of DC motor simulating wind generator,and introduced close-loop control scheme of the maximum output power of switched reluctance generating system based on the model.The simulation result shows that the control scheme enables the established power generating system into power adjustment and stable running.%针对传统的基于异步发电机、双馈发电机和永磁同步发电机的风力发电系统稳定性较差,风力发电系统的实验研究需要诸多条件、不易实现的问题,提出了一种在不具备风场实验条件情况下进行基于开关磁阻发电机的风力发电系统研究的方法,即采用直流电动机模拟风力机来进行开关磁阻发电系统的实验.建立了直流电动机模拟风力机的仿真模型,介绍了基于该模型的开关磁阻风力发电系统最大输出功率闭环控制方案.仿真结果表明,该控制方案能使所建立的发电系统快速进行功率调节并进入稳态工作.
A Simple and General Approach to Determination of Self and Mutual Inductances for AC machines
Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen
2011-01-01
Modelling of AC electrical machines plays an important role in electrical engineering education related to electrical machine design and control. One of the fundamental requirements in AC machine modelling is to derive the self and mutual inductances, which could be position dependant. Theories...... developed so far for inductance determination are often associated with complicated machine magnetic field analysis, which exhibits a difficulty for most students. This paper describes a simple and general approach to the determination of self and mutual inductances of different types of AC machines. A new...... determination are given for a 3-phase, salient-pole synchronous machine, and an induction machine....
Chikkagoudar, Satish; Chatterjee, Samrat; Thomas, Dennis G.; Carroll, Thomas E.; Muller, George
2017-04-21
The absence of a robust and unified theory of cyber dynamics presents challenges and opportunities for using machine learning based data-driven approaches to further the understanding of the behavior of such complex systems. Analysts can also use machine learning approaches to gain operational insights. In order to be operationally beneficial, cybersecurity machine learning based models need to have the ability to: (1) represent a real-world system, (2) infer system properties, and (3) learn and adapt based on expert knowledge and observations. Probabilistic models and Probabilistic graphical models provide these necessary properties and are further explored in this chapter. Bayesian Networks and Hidden Markov Models are introduced as an example of a widely used data driven classification/modeling strategy.
Design methodology for a special single winding based bearingless switched reluctance motor
Madhurjya Dev Choudhury
2017-06-01
Full Text Available Bearingless switched reluctance motors (BSRMs have both magnetic bearing as well as conventional motor characteristics which make them suitable for diverse industrial applications. This study proposes a design methodology for a BSRM in order to calculate the appropriate geometrical dimensions essential for realising a minimum levitation force at every orientation of rotor. It is based on the stator–rotor overlap angle and helps in reducing the complexities associated with the self-bearing operation of a switched reluctance motor (SRM. Different from a conventional SRM, the motor under study deploys a special single set parallel winding scheme for simultaneous production of torque as well as radial force. An analytical model incorporating this single set winding is developed for calculating the torque and the radial force. The proposed bearingless design is verified by developing a two-dimensional finite-element model of a 12/8 SRM in ANSYS Maxwell.
N. C. LENIN
2017-01-01
Full Text Available This paper presents the application of Soft Magnetic Composite (SMC material in Outer Rotating Switched Reluctance Motor (ORSRM. The presented stator core of the Switched Reluctance Motor was made of two types of material, the classical laminated silicon steel sheet and the soft magnetic composite material. First, the stator core made of laminated steel has been analysed. The next step is to analyse the identical geometry SRM with the soft magnetic composite material, SOMALOY for its stator core. The comparisons of both cores include the calculated torque and torque ripple, magnetic conditions, simplicity of fabrication and cost. The finite element method has been used to analyse the magnetic conditions and the calculated torque. Finally, tested results shows that SMC is a better choice for SRM in terms of torque ripple and power density.
Babak Ganji
2016-09-01
Full Text Available In the present paper, an electromagnetic simulation model is introduced for the conventional type of linear switched reluctance motor (LSRM in which the dynamic characteristics of the motor are predicted precisely by carrying out 2D finite element (FE transient analysis using ANSYS FE package. The simulation model is created totally in ANSYS parametric design language (APDL as a parametric model and it can be used easily for different designs of the conventional LSRMs. Introducing linear switched reluctance motor with segmental translator as a new type of LSRM, performance principles and design criteria are presented for two various topologies of this motor. Carrying out 2D FE transient analysis, dynamic characteristics of these two motors are predicted and compared to those obtained for the conventional LSRM.
A new sensorless speed control scheme for doubly fed reluctance generators
Ademi, Sul; Jovanovic, Milutin; Chaal, Hamza; Cao, Wenping
2016-01-01
This paper presents the development and experimental validation of a novel angular velocity observer-based field-oriented control algorithm for a promising low-cost brushless doubly fed reluctance generator (BDFRG) in wind power applications. The BDFRG has been receiving increasing attention because of the use of partially rated power electronics, the high reliability of brushless design, and competitive performance to its popular slip-ring counterpart, the doubly fed induction generator. The...
Dynamic Testing & Simulation of 4 KW (5.5 Hp Switched Reluctance Motor using PSpice
Rajesh Murlidharrao Autee
2011-09-01
Full Text Available Abstract- In this paper, the requirement of mechanical model of SR Motor for determination of dynamic characteristic is presented. The PSpice is circuit oriented software package and it is believed that no direct mechanical models are available. Therefore electrical equivalent of mechanical sub systems were used for determination of dynamic characteristics.The variable inductor model is also proposed using voltage controlled component.Index Terms – Switched Reluctance Motor, Dynamic Characteristics, Torque
Flux Concentration and Pole Shaping in a Single Phase Hybrid Switched Reluctance Motor Drive
Jakobsen, Uffe; Lu, Kaiyuan
2010-01-01
The single phase hybrid switched reluctance motor (HSRM) may be a good candidate for low-cost drives used for pump applications. This paper presents a new design of the HSRM with improved starting torque achieved by stator pole shaping, and a better arrangement of the embedded stator permanent...... magnets with flux concentration effects. Analysis and simulation results of the proposed HSRM drive are validated using experimental results on a prototype HSRM....
A Fault Diagnostic Method for Position Sensor of Switched Reluctance Wind Generator
Wang, Chao; Liu, Xiao; Liu, Hui;
2016-01-01
Fast and accurate fault diagnosis of the position sensor is of great significance to ensure the reliability as well as sensor fault tolerant operation of the Switched Reluctance Wind Generator (SRWG). This paper presents a fault diagnostic scheme for a SRWG based on the residual between the estim...... conditions. The results provide a feasible theoretical and technical basis for the effective condition monitoring and predictive maintenance of SRWG....
van Tuyl, Lilian H D; Plass, Anne Marie C; Lems, Willem F; Voskuyl, Alexandre E; Dijkmans, Ben A C; Boers, Maarten
2007-01-01
Background The Combinatietherapie Bij Reumatoide Artritis (COBRA) trial has proved that combination therapy with prednisolone, methotrexate and sulphasalazine is superior to sulphasalazine monotherapy in suppressing disease activity and radiological progression of early rheumatoid arthritis (RA). In addition, 5 years of follow‐up proved that COBRA therapy results in sustained reduction of the rate of radiological progression. Despite this evidence, Dutch rheumatologists seem reluctant to prescribe COBRA therapy. Objective To explore the reasons for the reluctance in Dutch rheumatologists to prescribe COBRA therapy. Methods A short structured questionnaire based on social–psychological theories of behaviour was sent to all Dutch rheumatologists (n = 230). Results The response rate was 50%. COBRA therapy was perceived as both effective and safe, but complex to administer. Furthermore, rheumatologists expressed their concern about the large number of pills that had to be taken, the side effects of high‐dose prednisolone and the low dose of methotrexate. Although the average attitude towards the COBRA therapy was slightly positive (above the neutral point), the majority of responding rheumatologists had a negative intention (below the neutral point) to prescribe COBRA therapy in the near future. Conclusion The reluctance of Dutch rheumatologists to prescribe effective COBRA therapy may be due to perceptions of complexity of the treatment schedule and negative patient‐related consequences of the therapy. PMID:17392349
The complex initial reluctivity, permeability and susceptibility spectra of magnetic materials
Hamilton, N. C.
2015-03-01
The HF complex permeability spectrum of a magnetic material is deduced from the measured impedance spectrum, which is then normalized to a series permeability spectrum. However, this series permeability spectrum has previously been shown to correspond to a parallel magnetic circuit, which is not appropriate. Some of the implications of this truth are examined. This electric/magnetic duality has frustrated efforts to interpret the shape of the complex magnetic permeability spectra of materials, and has hindered the application of impedance spectroscopy to magnetic materials. In the presence of magnetic loss, the relationship between the relative magnetic permeability and the magnetic susceptibility is called into question. The use of reluctivity spectra for expressing magnetic material properties is advocated. The relative loss factor, tanδm/μi is shown to be an approximation for the imaginary part of the reluctivity. A single relaxation model for the initial reluctivity spectra of magnetic materials is presented, and its principles are applied to measurements of a high permeability ferrite. The results are presented as contour plots of the spectra as a function of temperature.
Numerical study on electromagnetics and thermal cooling of a switched reluctance motor
Jer-Huan Jang
2015-09-01
Full Text Available In this study, the coupled thermomagnetic system of a switched reluctance motor for cooling performance improvement has been conducted numerically. The switched reluctance motor (SRM with output power of 3 kW and air cooling is under investigation. Aluminum cooling fins are fitted on the cooling casing of the motor in order to increase the convection surfaces. The commercial softwares used in this paper are JMAG-Designer and CFD-RC for electromagnetic field and thermal field analyzes, respectively. The electro-magnetic analysis for the switched reluctance motor is obtained in advanced in order to obtain the energy losses. They can then be treated as the heat sources for heat transfer analysis. Transient solutions for the temperatures of the components in SRM are calculated during operation. The transient temperature of SRM is analyzed for both with and without cooling casing. The influence of forced convection by the internal fan of the SRM is also under investigation. Results show the numerical model is in good agreement to the real practice. The model can be used for the SRM cooling design.
van Tuyl, Lilian H D; Plass, Anne Marie C; Lems, Willem F; Voskuyl, Alexandre E; Dijkmans, Ben A C; Boers, Maarten
2007-07-01
The Combinatietherapie Bij Reumatoide Artritis (COBRA) trial has proved that combination therapy with prednisolone, methotrexate and sulphasalazine is superior to sulphasalazine monotherapy in suppressing disease activity and radiological progression of early rheumatoid arthritis (RA). In addition, 5 years of follow-up proved that COBRA therapy results in sustained reduction of the rate of radiological progression. Despite this evidence, Dutch rheumatologists seem reluctant to prescribe COBRA therapy. To explore the reasons for the reluctance in Dutch rheumatologists to prescribe COBRA therapy. A short structured questionnaire based on social-psychological theories of behaviour was sent to all Dutch rheumatologists (n = 230). The response rate was 50%. COBRA therapy was perceived as both effective and safe, but complex to administer. Furthermore, rheumatologists expressed their concern about the large number of pills that had to be taken, the side effects of high-dose prednisolone and the low dose of methotrexate. Although the average attitude towards the COBRA therapy was slightly positive (above the neutral point), the majority of responding rheumatologists had a negative intention (below the neutral point) to prescribe COBRA therapy in the near future. The reluctance of Dutch rheumatologists to prescribe effective COBRA therapy may be due to perceptions of complexity of the treatment schedule and negative patient-related consequences of the therapy.
Synchronously deployable truss structure
Bush, H. G. (Inventor); Mikulas, M., Jr. (Inventor); Wallsom, E. (Inventor)
1986-01-01
A collapsible-expandable truss structure, including first and second spaced surface truss layers having an attached core layer is described. The surface truss layers are composed of a plurality of linear struts arranged in multiple triangular configurations. Each linear strut is hinged at the center and hinge connected at each end to a nodular joint. A passive spring serves as the expansion force to move the folded struts from a stowed collapsed position to a deployed operative final truss configuration. A damper controls the rate of spring expansion for the synchronized deployment of the truss as the folded configuration is released for deployment by the restrain belts. The truss is synchronously extended under the control of motor driven spools.
Synchronization of micromasers
Davis-Tilley, C.; Armour, A. D.
2016-12-01
We investigate synchronization effects in quantum self-sustained oscillators theoretically using the micromaser as a model system. We use the probability distribution for the relative phase as a tool for quantifying the emergence of preferred phases when two micromasers are coupled together. Using perturbation theory, we show that the behavior of the phase distribution is strongly dependent on exactly how the oscillators are coupled. In the quantum regime where photon occupation numbers are low we find that, although synchronization effects are rather weak, they are nevertheless significantly stronger than expected from a semiclassical description of the phase dynamics. We also compare the behavior of the phase distribution with the mutual information of the two oscillators and show that they can behave in rather different ways.
De Chiffre, Leonardo
This document is used in connection with a laboratory exercise of 3 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercise includes a series of tests carried out by the student on a conventional and a numerically controled lathe, respectively. This document...
Petersson, Dag; Dahlgren, Anna; Vestberg, Nina Lager
to the enterprises of the medium. This is the subject of Representational Machines: How photography enlists the workings of institutional technologies in search of establishing new iconic and social spaces. Together, the contributions to this edited volume span historical epochs, social environments, technological...
Introduction to the Report "Interlanguages and Synchronic Models of Computation."
Berka, Alexander Victor
2010-01-01
A novel language system has given rise to promising alternatives to standard formal and processor network models of computation. An interstring linked with a abstract machine environment, shares sub-expressions, transfers data, and spatially allocates resources for the parallel evaluation of dataflow. Formal models called the a-Ram family are introduced, designed to support interstring programming languages (interlanguages). Distinct from dataflow, graph rewriting, and FPGA models, a-Ram instructions are bit level and execute in situ. They support sequential and parallel languages without the space/time overheads associated with the Turing Machine and l-calculus, enabling massive programs to be simulated. The devices of one a-Ram model, called the Synchronic A-Ram, are fully connected and simpler than FPGA LUT's. A compiler for an interlanguage called Space, has been developed for the Synchronic A-Ram. Space is MIMD. strictly typed, and deterministic. Barring memory allocation and compilation, modules are ref...
Successful synchronization of the LHC's clockwise beam transfer system
2008-01-01
LHC synchronization test successful The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.
Successful attack on permutation-parity-machine-based neural cryptography.
Seoane, Luís F; Ruttor, Andreas
2012-02-01
An algorithm is presented which implements a probabilistic attack on the key-exchange protocol based on permutation parity machines. Instead of imitating the synchronization of the communicating partners, the strategy consists of a Monte Carlo method to sample the space of possible weights during inner rounds and an analytic approach to convey the extracted information from one outer round to the next one. The results show that the protocol under attack fails to synchronize faster than an eavesdropper using this algorithm.
Adding machine and calculating machine
无
2005-01-01
In 1642 the French mathematician Blaise Pascal(1623-1662) invented a machine;.that could add and subtract. It had.wheels that each had: 1 to 10 marked off along its circumference. When the wheel at the right, representing units, made one complete circle, it engaged the wheel to its left, represents tens, and moved it forward one notch.
Determination of a synchronous generator characteristics via Finite Element Analysis
Kolondzovski Zlatko
2005-01-01
Full Text Available In the paper a determination of characteristics of a small salient pole synchronous generator (SG is presented. Machine characteristics are determined via Finite Element Analysis (FEA and for that purpose is used the software package FEMM Version 3.3. After performing their calculation and analysis, one can conclude that most of the characteristics presented in this paper can be obtained only by using the Finite Element Method (FEM.
Permanent Magnet Synchronous Condenser with Solid State Excitation
Hsu, Ping; Muljadi, Eduard; Wu, Ziping; Gao, Wenzhong
2015-10-05
A synchronous condenser consists of a free-spinning wound-field synchronous generator and a field excitation controller. In this paper, we propose a synchronous generator that employs a permanent magnet synchronous generator (PMSG) instead of a wound-field machine. PMSGs have the advantages of higher efficiency and reliability. In the proposed configuration, the reactive power control is achieved by a voltage source converter connected in series with the PMSG and the grid. The converter varies the phase voltage of the PMSG so as to create the same effect of over or under excitation in a wound-field machine. The converter output voltage level controls the amount and the direction of the produced reactive power and the voltage's phase is kept in-phase with the grid voltage except a slight phase can be introduced so that some power can be drawn from the grid for maintaining the DC bus voltage level of the converter. Since the output voltage of the converter is only a fraction of the line voltage, its VA rating is only a fraction of the rating of the PMSG. The proposed scheme is shown to be effective by computer simulation.
Ilkjær, Helene
2016-01-01
Taking its point of departure in the personal story of Nalini, this article examines highly skilled Indian women’s experiences of moving back to India after years of working and living with their families abroad. The article touches on themes of gender relations, family commitments, career...... opportunities, and social and cultural conservatism within the context of recent waves of return migration to Bangalore, a prominent hub in the imaginary of a “new” globalising India. Tracing Nalini’s story in and out of states of depression, the article points to ways in which returnee women find their own...
The transient ladder synchronization of chaotic systems
Chen, H.-K. [Department of Industrial Engineering and Management, Hsiuping Institute of Technology, No. 11, Gungye Rd., Dali City, Taichung, Taiwan (China)]. E-mail: kanechen@giga.net.tw; Sheu, L.-J. [Department of Mechanical Engineering, Chung Hua University, Hsinchu, Taiwan (China)]. E-mail: ljsheu@chu.edu.tw
2006-07-03
A new type for chaotically synchronizing systems, transient ladder chaos synchronization, is proposed in this Letter. For some physical systems, chaotic synchronization is possible in only some of the variables. It is shown that, for the non-synchronizing variable, synchronization up to a constant difference for t{sub 1}=
Amos, Martyn
2014-01-01
Silicon chips are out. Today's scientists are using real, wet, squishy, living biology to build the next generation of computers. Cells, gels and DNA strands are the 'wetware' of the twenty-first century. Much smaller and more intelligent, these organic computers open up revolutionary possibilities. Tracing the history of computing and revealing a brave new world to come, Genesis Machines describes how this new technology will change the way we think not just about computers - but about life itself.
Segura Ozuna, Victor Octavio; Hernandez Rodriguez, Isaura Victoria; Alcaide Godinez, Indira Xochiquetzal; Garduno Ramirez, Raul; Montero Cervantes, Julio Cesar [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Ruiz Rodriguez, Genaro; Martinez Torres; Ricardo [CFE-LAPEM, Irapuato, Guanajuato (Mexico)
2012-07-01
This paper introduces a characterization of the behavior of the speed and voltage control systems of a special purpose synchronous machine (GCC) based on measuring and monitoring physical signals, and recording of the sampled waveforms. Basically, the GCC supplies the energy to perform high-power short-circuits tests to certify electrical equipment and components, as required by the Comision Federal de Electricidad (CFE) in Mexico. The GCC operates alternately as motor and generator. With the GCC operating as motor, speed control during startup, acceleration, re-acceleration and braking is carried out by a static frequency converter (SFC). Complementary, the voltage controller manipulates excitation power to control terminal voltage when the GCC operates as generator and regulates excitation current when the GCC operates as motor. Compared to conventional voltage regulation systems, which must go off in case of short-circuit, the GCC voltage regulator must keep controlling field excitation to maintain the required line current and terminal voltage during short-circuit tests. Monitoring of physical signals was carried out with a portable data acquisition system based on SCXI and PXI digital platforms. A total of 78 signals were monitored with a 6 kHz sampling rate that was enough to obtain detailed signal waveforms. Data captured was processed and plotted for analysis. The signal graphs show the current real behavior of both, the voltage control system and the speed control system, and constitute a precise characterization of their behavior. [Spanish] Este documento presenta una caracterizacion del comportamiento de los sistemas de control de velocidad y voltaje de una maquina sincrona de proposito especial (GCC) basada en la medicion y monitoreo de senales fisicas, asi como en el registro de las formas de onda muestreadas. Basicamente, la GCC suministra la energia para efectuar pruebas de corto circuito de alta potencia para certificar equipo y componentes
刘英培; 栗然; 梁海平
2014-01-01
Traditional PI regulator has some defects. Direct torque control (DTC) for permanent magnet synchronous motor (PMSM) based on active-disturbance rejection control (ADRC) optimized by least squares support vector machines (LSSVM) method was proposed in this paper. The speed regulator based on ADRC was designed with the inputs of given speed and real speed and the output of given electromagnet torque. The Gaussian radial basis kernel function was chosen in the model. The realization of the LSSVM regression model embedded in ADRC regulator was analyzed in-depth and detailed, which optimized the ADRC regulator. The ADRC observation precision and dynamic response are improved. The effect of motor parameters and load disturbances on the system is significantly reduced. The anti-interference ability of the system is further improved. Simulation and experiment results have verified the feasibility and effectiveness of this method.%针对传统PI调节器的缺陷，提出一种基于最小二乘支持向量机(least squares support vector machine，LSSVM)优化自抗扰控制器(active-disturbance rejection control， ADRC)的永磁同步电机直接转矩控制方法。以给定转速和实际转速作为输入信号，以给定电磁转矩作为输出信号，设计了 ADRC 速度调节器；在此基础上，在回归模型中选取高斯径向基核函数，深入分析了将LSSVM回归模型有效嵌入ADRC调节器的实现方法，实现对ADRC控制器的优化，以提高 ADRC 观测精度及系统动态响应速度，很大程度上降低了电机参数变化和负载扰动对系统的影响，进一步改善了系统的抗干扰能力。仿真和实验结果验证了该方法的可行性和有效性。
刘文田
2012-01-01
In order to meet the features and performance of thin coal seam shearer, the switched reluctance motor control system is being researched, which is suitable for traction system of thin coal seam shearer. The system uses fully digital control and the CAN-bus to make double motor SRD （Synchronous Reluctance Driver）, and the floor installation of patented technology. The system can meet the requirements for thin coal seam by performance test.%为满足薄煤层采煤机的特点和性能指标，研制了一种适合薄煤层采煤机行走系统的开关磁阻电动机控制系统。系统采用了全数字控制，使用CAN总线控制实现双机同步，采用专利技术的底板安装方式。该系统通过性能试验满足了薄煤层采煤机的要求。
High Performance Variable Speed Drive System and Generating System with Doubly Fed Machines
Tang, Yifan
Doubly fed machines are another alternative for variable speed drive systems. The doubly fed machines, including doubly fed induction machine, self-cascaded induction machine and doubly excited brushless reluctance machine, have several attractive advantages for variable speed drive applications, the most important one being the significant cost reduction with a reduced power converter rating. With a better understanding, improved machine design, flexible power converters and innovated controllers, the doubly fed machines could favorably compete for many applications, which may also include variable speed power generations. The goal of this research is to enhance the attractiveness of the doubly fed machines for both variable speed drive and variable speed generator applications. Recognizing that wind power is one of the favorable clean, renewable energy sources that can contribute to the solution to the energy and environment dilemma, a novel variable-speed constant-frequency wind power generating system is proposed. By variable speed operation, energy capturing capability of the wind turbine is improved. The improvement can be further enhanced by effectively utilizing the doubly excited brushless reluctance machine in slip power recovery configuration. For the doubly fed machines, a stator flux two -axis dynamic model is established, based on which a flexible active and reactive power control strategy can be developed. High performance operation of the drive and generating systems is obtained through advanced control methods, including stator field orientation control, fuzzy logic control and adaptive fuzzy control. System studies are pursued through unified modeling, computer simulation, stability analysis and power flow analysis of the complete drive system or generating system with the machine, the converter and the control. Laboratory implementations and tested results with a digital signal processor system are also presented.
Remote Synchronization in Complex Networks
Gambuzza, Lucia Valentina; Fiasconaro, Alessandro; Fortuna, Luigi; Gómez-Gardeñes, Jesús; Frasca, Mattia
2013-01-01
We show the existence of a novel dynamical state called remote synchronization in general networks of coupled oscillators. This state is characterized by the synchronization of pairs of nodes that are not directly connected via a physical link or any sequence of synchronized nodes. This phenomenon cannot be observed in networks of phase oscillators as its underlying mechanism is the modulation of the amplitude of those intermediary nodes between the remotely synchronized units. Our findings thus show the ubiquity and robustness of these states and bridge the gap from their recent observation in simple toy graphs to complex networks.
PARTIAL SYNCHRONIZATION BETWEEN DIFFERENT SYSTEMS
CHEN Jun; LIU Zeng-rong
2005-01-01
A new method for partial synchronization between different systems was obtained. The definition of partial synchronization under which the problem works is given. The stability of the method is analyzed by the Liapunov function method and the condition of choosing the control term is derived. The reliability of this method is proved by some numerical examples, in which the dynamical behaviors of the synchronized systems are observed and it is found that whatever state the response system is partial synchronization can be always achieved by adding some proper control term.
Simulation and experimental results of hybrid electric machine with a novel flux control strategy
Paplicki Piotr
2015-03-01
Full Text Available The paper presents selected simulation and experimental results of a hybrid ECPMS-machine (Electric Controlled Permanent Magnet Synchronous Machine. This permanent magnets (PMs excited machine offers an extended magnetic field control capability which makes it suitable for battery electric vehicle (BEV drives. Rotor, stator and the additional direct current control coil of the machine are analyzed in detail. The control system and strategy, the diagram of power supply system and an equivalent circuit model of the ECPMS-machine are presented. Influence of the additional excitation on the performance parameters of the machine, such as: torque, efficiency, speed limits and back-EMF have also been discussed.
Simulating Turing machines on Maurer machines
Bergstra, J.A.; Middelburg, C.A.
2008-01-01
In a previous paper, we used Maurer machines to model and analyse micro-architectures. In the current paper, we investigate the connections between Turing machines and Maurer machines with the purpose to gain an insight into computability issues relating to Maurer machines. We introduce ways to
骆光照; 张围围; 杨南方; 马鹏; 刘卫国
2012-01-01
A flux linkage compensation field oriented control (FOC) method was proposed to suppress the speed and torque ripples of a hrusbless wound-fleld synchronous motor in its starting process. The starting process was analyzed and the model of wound-field synchronous electric machine was established. The change of field current of the electric machine was described mathematically for simplified exciter and rotate rectifier. Based on the traditional field control, the flux linkage compensation was introduced in d-axis current to counteract the flux ripple. Some simulation and preliminary experiments were implemented. The results show that the proposed method is feasible and effective.
FPGA based fast synchronous serial multi-wire links synchronization
Pozniak, Krzysztof T.
2013-10-01
The paper debates synchronization method of multi-wire, serial link of constant latency, by means of pseudo-random numbers generators. The solution was designed for various families of FPGA circuits. There were debated synchronization algorithm and functional structure of parameterized transmitter and receiver modules. The modules were realized in VHDL language in a behavioral form.
Environmentally Friendly Machining
Dixit, U S; Davim, J Paulo
2012-01-01
Environment-Friendly Machining provides an in-depth overview of environmentally-friendly machining processes, covering numerous different types of machining in order to identify which practice is the most environmentally sustainable. The book discusses three systems at length: machining with minimal cutting fluid, air-cooled machining and dry machining. Also covered is a way to conserve energy during machining processes, along with useful data and detailed descriptions for developing and utilizing the most efficient modern machining tools. Researchers and engineers looking for sustainable machining solutions will find Environment-Friendly Machining to be a useful volume.
Ni, Ronggang; Xu, Dianguo; Wang, Gaolin
2016-01-01
the application field. The system electromechanical model during switching is deduced and analyzed numerically to verify the stability under grid drive. For the control strategy, model-based sliding-mode observer is adopted during soft start for low-cost position sensorless drive, and two digital phase lock loops...
Design and Parametr Analysis of Switched Reluctance Motor with Permanent Magnets
Ivan Trak
2004-01-01
Full Text Available This paper deals with Switched Reluctance Motor (SRM parametr investigation, if permanent magnets are suitable inserted in stator parts to increase magnetic flux. The analysis is made on the base of input geometrical dimensions and materials of a real SRM without permanent magnets (PM. The calculation of PMSRM static parametres is made by means of Finite Element Method (FEM and by analytical approach. The output parameters of PMSRM analysis are phase inductance, flux linage and electromagnetic torque versus phase current and rotor position. These calculated parameters are compared with measured and FEM calculated parameters of SRM without PM. The recommendations for PMSRM design configuration are given.
Nishizawa, Hitoshi; Yoshioka, Takayoshi; Itoh, Kazuaki
This article introduces extensive reading (ER) as an approach to improve fundamental communication skills in English of reluctant EFL learners : average Japanese engineering students. It is distinct from concurrent translation approach from a perspective that the learners use English instead of Japanese to grasp the meaning of what they read and enjoy reading. In the ER program at Toyota National College of Technology, many students developed more positive attitude toward English, increased their reading speed, and achieved higher TOEIC scores, which was compared to those of the students before this ER program was introduced. Comparison between three groups of the students showed strong correlation between their TOEIC scores and the reading amount.
A new two-phase homopolar switched reluctance motor for electric vehicle applications
Tsai, Mi-Ching; Huang, Chien-Chin; Huang, Zheng-Yi
2003-12-01
This paper presents a novel 2-phase homopolar switched reluctance motor (SRM), whose design successfully avoids dead-zone problems that afflict low cost 1- and/or 2-phase SRMs. Unlike conventional radial-winding-radial-gap motors, the proposed SRM has an interior stator that is of the pancake type with axial winding. Such a design allows for a high slot-fill factor and is suitable for implementation as a flat pancake-shaped stator. An efficient, compact prototype was produced with TMS320F240 DSP driving control unit. Experimental results indicate that the present SRM design has the potential to be used for electric bicycles and scooters.
Design trends and trade-offs for sensorless operation of switched reluctance motor drives
Perl, T.; Husain, I.; Elbuluk, M. [Univ. of Akron, OH (United States). Dept. of Electrical Engineering
1995-12-31
The aligned to unaligned phase inductance ratio and the number of stator and rotor poles strongly affect the resolution of indirect rotor position sensing methods for switched reluctance motor (SRM) drives. A higher inductance ratio increases the resolution, while higher number of phases increases the available sampling window for indirect position sensing. However, these requirements are conflicting design criteria for an SRM. In this paper, the design considerations and trade-offs for sensorless SRM drives are analyzed by computer simulations. The existing indirect position sensing methods and their applicability for various SRM drives are also discussed.
N.C. Lenin
2010-06-01
Full Text Available In this paper, the results of a finite element analysis are carried out on new stator geometry of a three phase longitudinal flux Linear Switched Reluctance Motor (LSRM. In the new geometry, pole shoes are affixed to the stator poles. Static and dynamic characteristics for the proposed structure have been highlighted. Motor performance for variable load conditions is discussed. The 2-Dimensional (2-D finite element analysis (FEA and the experimental results of this paper prove that LSRMs are one of the strong candidates for linear propulsion drive
A non-unity torque sharing function for torque ripple minimization of switched reluctance generators
Park, Kiwoo; Liu, Xiao; Chen, Zhe
2013-01-01
This paper presents a new torque ripple minimization technique for a Switched Reluctance Generator (SRG). Although the SRG has many advantageous characteristics as a generator, it has not been widely employed in the industry. One of the most notorious disadvantages of the SRG is its high torque r...... ripple. In this paper, a non-unity Torque Sharing Function (TSF) is proposed to minimize the torque ripple over a wide speed range of operation. Simulation results are presented to verify the effectiveness of the proposed torque ripple minimization technique....
Knight, K; Knight, Kevin; Graehl, Jonathan
1997-01-01
It is challenging to translate names and technical terms across languages with different alphabets and sound inventories. These items are commonly transliterated, i.e., replaced with approximate phonetic equivalents. For example, "computer" in English comes out as "konpyuutaa" in Japanese. Translating such items from Japanese back to English is even more challenging, and of practical interest, as transliterated items make up the bulk of text phrases not found in bilingual dictionaries. We describe and evaluate a method for performing backwards transliterations by machine. This method uses a generative model, incorporating several distinct stages in the transliteration process.
Generalized theory of mixed pole machines with a general rotor configuration
Ayman S. Abdel-khalik
2013-03-01
Full Text Available This paper introduces a generalized theory for the operation of mixed pole machines (MPMs. The MPM has two stator windings, namely the main winding with pole pairs P1 and the control winding with pole pairs P2. The MPM has shown promise in the field of adjustable speed drives for large machines and in the field of wind energy electrical generation. The operation of MPM relies on the interaction between the two fields produced by the two stator windings through the intermediate action of a specially designed rotor (nested-cage or reluctance rotor. The machine theory is described from a physical aspect rather than mathematical derivations. A simple representation is also presented, from which the machine d–q model can be readily deduced. The effect of mechanical loading on the relative positions of the machine fields is also presented.
Global Exponential Projective Synchronization and Lag Synchronization of Hyperchaotic Lü System
ZHANG Qun-Jiao; LU Jun-An; JIA Zhen
2009-01-01
This paper investigates the projective synchronization and lag synchronization of a new hyperchaotic system[Physica A 364 (2006) 103]. On the basis of Lyapunov stability theory, two novel nonlinear controllers are respectively designed to guarantee the global exponential projective synchronization (including complete synchronization and anti-synchronization) and lag synchronization. Finally, numerical simulations are given to show the effectiveness of the main results.
Schmidt, R
2014-01-01
The protection of accelerator equipment is as old as accelerator technology and was for many years related to high-power equipment. Examples are the protection of powering equipment from overheating (magnets, power converters, high-current cables), of superconducting magnets from damage after a quench and of klystrons. The protection of equipment from beam accidents is more recent. It is related to the increasing beam power of high-power proton accelerators such as ISIS, SNS, ESS and the PSI cyclotron, to the emission of synchrotron light by electron–positron accelerators and FELs, and to the increase of energy stored in the beam (in particular for hadron colliders such as LHC). Designing a machine protection system requires an excellent understanding of accelerator physics and operation to anticipate possible failures that could lead to damage. Machine protection includes beam and equipment monitoring, a system to safely stop beam operation (e.g. dumping the beam or stopping the beam at low energy) and an ...
Digital synchronization and communication techniques
Lindsey, William C.
1992-01-01
Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.
Order release in synchronous manufacturing
Riezebos, J.
2010-01-01
Synchronous manufacturing aims at achieving the benefits of intermittent production lines in production situations that operate without lines. Benefits such as short and constant throughput times and predictable capacity loading can be acquired through an appropriate design of the synchronous manufa
Biologically Inspired Intercellular Slot Synchronization
Alexander Tyrrell
2009-01-01
Full Text Available The present article develops a decentralized interbase station slot synchronization algorithm suitable for cellular mobile communication systems. The proposed cellular firefly synchronization (CelFSync algorithm is derived from the theory of pulse-coupled oscillators, common to describe synchronization phenomena in biological systems, such as the spontaneous synchronization of fireflies. In order to maintain synchronization among base stations (BSs, even when there is no direct link between adjacent BSs, some selected user terminals (UTs participate in the network synchronization process. Synchronization emerges by exchanging two distinct synchronization words, one transmitted by BSs and the other by active UTs, without any a priori assumption on the initial timing misalignments of BSs and UTs. In large-scale networks with inter-BS site distances up to a few kilometers, propagation delays severely affect the attainable timing accuracy of CelFSync. We show that by an appropriate combination of CelFSync with the timing advance procedure, which aligns uplink transmission of UTs to arrive simultaneously at the BS, a timing accuracy within a fraction of the inter-BS propagation delay is retained.
Exploiting Schemas in Data Synchronization
Foster, J. Nathan; Greenwald, Michael B.; Kirkegaard, Christian
2005-01-01
Increased reliance on optimistic data replication has led to burgeoning interest in tools and frameworks for disconnected updates to replicated data.We have implemented a generic synchronization framework, called HARMONY, that can be used to build state-based synchronizers for a wide variety of t...
Benefits of Synchronous Online Courses
Moser, Scott; Smith, Phil
2015-01-01
Most online courses are offered as "asynchronous" courses and have no real-time contact with students. The Synchronous online alternative provides normal scheduled class time and allows students to login to a virtual online classroom with the instructor. We provide an overview of two different platforms for hosting synchronous classes…
Network algebra for synchronous dataflow
Bergstra, J.A.; Middelburg, C.A.; Ștefánescu, G.
2013-01-01
We develop an algebraic theory of synchronous dataflow networks. First, a basic algebraic theory of networks, called BNA (Basic Network Algebra), is introduced. This theory captures the basic algebraic properties of networks. For synchronous dataflow networks, it is subsequently extended with
Order release in synchronous manufacturing
Riezebos, J.
2010-01-01
Synchronous manufacturing aims at achieving the benefits of intermittent production lines in production situations that operate without lines. Benefits such as short and constant throughput times and predictable capacity loading can be acquired through an appropriate design of the synchronous manufa
Synchronization dynamics of two different dynamical systems
Luo, Albert C.J., E-mail: aluo@siue.edu [Department of Mechanical and Industrial Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1805 (United States); Min Fuhong [Department of Mechanical and Industrial Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1805 (United States)
2011-06-15
Highlights: > Synchronization dynamics of two distinct dynamical systems. > Synchronization, de-synchronization and instantaneous synchronization. > A controlled pendulum synchronizing with the Duffing oscillator. > Synchronization invariant set. > Synchronization parameter map. - Abstract: In this paper, synchronization dynamics of two different dynamical systems is investigated through the theory of discontinuous dynamical systems. The necessary and sufficient conditions for the synchronization, de-synchronization and instantaneous synchronization (penetration or grazing) are presented. Using such a synchronization theory, the synchronization of a controlled pendulum with the Duffing oscillator is systematically discussed as a sampled problem, and the corresponding analytical conditions for the synchronization are presented. The synchronization parameter study is carried out for a better understanding of synchronization characteristics of the controlled pendulum and the Duffing oscillator. Finally, the partial and full synchronizations of the controlled pendulum with periodic and chaotic motions are presented to illustrate the analytical conditions. The synchronization of the Duffing oscillator and pendulum are investigated in order to show the usefulness and efficiency of the methodology in this paper. The synchronization invariant domain is obtained. The technique presented in this paper should have a wide spectrum of applications in engineering. For example, this technique can be applied to the maneuvering target tracking, and the others.
Torque Characteristics of Saturated Permanent-Magnet Synchronous Motors
Takahashi, Akeshi; Kikuchi, Satoshi; Wakui, Shinichi; Mikami, Hiroyuki; Ide, Kazumasa; Shima, Kazuo
The evaluation of torque characteristics in a saturated magnetic field for permanent-magnet (PM) synchronous motors is presented. The torque saturation characteristics of non-salient and salient pole machines are investigated by finite element analysis and measurement. Thus, it is found that the torque saturation originates in the magnetic saturation in both the stator teeth, which are located on the leading position toward the direct axis, and in the stator back yoke, which is located on the lagging position toward the direct axis. This mechanism can also explain the reason for the significant torque saturation in the salient-pole machine; the higher inductance of the quadrature axis of the salient-pole machine causes a significant magnetic saturation in the stator back yoke. Therefore, less saliency or a wider back yoke can improve the torque saturation.
Chua's Circuit: Control and Synchronization
Irimiciuc, Stefan-Andrei; Vasilovici, Ovidiu; Dimitriu, Dan-Gheorghe
Chaos-based data encryption is one of the most reliable methods used in secure communications. This implies a good control of a chaotic system and a good synchronization between the involved systems. Here, experimental results are shown on the control and synchronization of Chua's circuits. The control of the chaotic circuit was achieved by using the switching method. The influence of the control signal characteristics (amplitude, frequency and shape) on the system's states was also investigated. The synchronization of two similar chaotic circuits was studied, emphasizing the importance of the chaotic state characteristics of the Master system in respect to those of Slave system. It was shown that the synchronization does not depend on the chaotic state type, neither on the dimension (x, y or z) used for synchronization.
Balancing Contention and Synchronization on the Intel Paragon
Bokhari, Shahid H.; Nicol, David M.
1996-01-01
The Intel Paragon is a mesh-connected distributed memory parallel computer. It uses an oblivious and deterministic message routing algorithm: this permits us to develop highly optimized schedules for frequently needed communication patterns. The complete exchange is one such pattern. Several approaches are available for carrying it out on the mesh. We study an algorithm developed by Scott. This algorithm assumes that a communication link can carry one message at a time and that a node can only transmit one message at a time. It requires global synchronization to enforce a schedule of transmissions. Unfortunately global synchronization has substantial overhead on the Paragon. At the same time the powerful interconnection mechanism of this machine permits 2 or 3 messages to share a communication link with minor overhead. It can also overlap multiple message transmission from the same node to some extent. We develop a generalization of Scott's algorithm that executes complete exchange with a prescribed contention. Schedules that incur greater contention require fewer synchronization steps. This permits us to tradeoff contention against synchronization overhead. We describe the performance of this algorithm and compare it with Scott's original algorithm as well as with a naive algorithm that does not take interconnection structure into account. The Bounded contention algorithm is always better than Scott's algorithm and outperforms the naive algorithm for all but the smallest message sizes. The naive algorithm fails to work on meshes larger than 12 x 12. These results show that due consideration of processor interconnect and machine performance parameters is necessary to obtain peak performance from the Paragon and its successor mesh machines.
Synchronous anorectal melanoma
Drinko Balicevic; Karla Tomic; Miroslav Bekavac-Beslin; Igor Kovacevic; August Mijic; Mladen Belicza; Bozo Kruslin
2006-01-01
Anorectal melanoma is a very rare tumor with poor prognosis. Rectal bleeding is the most frequent symptom and surgical treatment ranges from local excision to radical abdominoperineal resection. We report a case of a 75-years-old male patient who presented with a history of recurrent rectal bleeding, and whose histopathological diagnosis was melanoma. Macroscopically, we found two distinct tumors in anorectal region, 0.5 cm and 1.5 cm from dentate line. The first one was pedunculated, on a thin stalk, measuring 1 cm in greatest diameter, and the second one was sessile and nodular measuring up to 2.8 cm in largest diameter. Microscopic examination and immunohistochemical analysis of both tumors confirmed the diagnosis of melanoma. This case represents multiple synchronous primary melanoma of the anorectal region, with a possibility that one of the lesions is primary melanoma and the second one is a satellite lesion.
Hansen, Erik W.
, to exist, in order to underline the cognitive basis of man's (comprehension of) existence. A theory of history (existence) is set up on the basis of the traditional dualistic sign function, and the traditional sound-law concept and sound development are reinterpreted in terms of the theory's system...... of definitions. Historical linguistics ('change') is not dependent on an arbitrary synchronic theory. The two language universals polysemy and synonymy are reinterpreted and defined in accordance with the advanced definitions. Louis Hjelmslev's glossematic theory is the general horizon of the argument...... and is criticized for being based on a dated metaphysics. Two epistemological principles are introduced, The Phenomenal Error and The Critico-Philological Method. Conclusion: Historical linguistics is an autonomous scientific discipline. ...
Condition monitoring of gearboxes using synchronously averaged electric motor signals
Ottewill, J. R.; Orkisz, M.
2013-07-01
Due to their prevalence in rotating machinery, the condition monitoring of gearboxes is extremely important in the minimization of potentially dangerous and expensive failures. Traditionally, gearbox condition monitoring has been conducted using measurements obtained from casing-mounted vibration transducers such as accelerometers. A well-established technique for analyzing such signals is the synchronous signal average, where vibration signals are synchronized to a measured angular position and then averaged from rotation to rotation. Driven, in part, by improvements in control methodologies based upon methods of estimating rotor speed and torque, induction machines are used increasingly in industry to drive rotating machinery. As a result, attempts have been made to diagnose defects using measured terminal currents and voltages. In this paper, the application of the synchronous signal averaging methodology to electric drive signals, by synchronizing stator current signals with a shaft position estimated from current and voltage measurements is proposed. Initially, a test-rig is introduced based on an induction motor driving a two-stage reduction gearbox which is loaded by a DC motor. It is shown that a defect seeded into the gearbox may be located using signals acquired from casing-mounted accelerometers and shaft mounted encoders. Using simple models of an induction motor and a gearbox, it is shown that it should be possible to observe gearbox defects in the measured stator current signal. A robust method of extracting the average speed of a machine from the current frequency spectrum, based on the location of sidebands of the power supply frequency due to rotor eccentricity, is presented. The synchronous signal averaging method is applied to the resulting estimations of rotor position and torsional vibration. Experimental results show that the method is extremely adept at locating gear tooth defects. Further results, considering different loads and different
Analysis of machining and machine tools
Liang, Steven Y
2016-01-01
This book delivers the fundamental science and mechanics of machining and machine tools by presenting systematic and quantitative knowledge in the form of process mechanics and physics. It gives readers a solid command of machining science and engineering, and familiarizes them with the geometry and functionality requirements of creating parts and components in today’s markets. The authors address traditional machining topics, such as: single and multiple point cutting processes grinding components accuracy and metrology shear stress in cutting cutting temperature and analysis chatter They also address non-traditional machining, such as: electrical discharge machining electrochemical machining laser and electron beam machining A chapter on biomedical machining is also included. This book is appropriate for advanced undergraduate and graduate mechani cal engineering students, manufacturing engineers, and researchers. Each chapter contains examples, exercises and their solutions, and homework problems that re...
Rotor Position Detection of Switched Reluctance Motors with a New Indirect Technique
Majid Asgar
2014-09-01
Full Text Available The aligned to unaligned phase inductance ratio and the number of stator and rotor poles strongly affect the resolution of indirect rotor position sensing methods for switched reluctance motor (SRM drives. This paper presents a new sensor-less rotor position detection for a three-phase single switch SR motor with regeneration capability at standstill mode.. The proposed method is based on the dependency of phase current waveform at turn off time to rotor position angle. It is shown that the combination of a motor with single switch per phase converter and a transient voltage suppressor (TVS circuit deﬁne a resonant circuit. In this method, the rotor position is achieved by inspecting of regeneration current results of applied high frequency and low level diagnostic pulses to the motor phases at the beginning step. Obtaining the rotor position of switched reluctance motors (SRMs will done by means of the overlap of rising voltage measurements. During this interval, rotor position is detected by exchanging energy between the phase and source repeatedly in one cycle of a phase current. The resulted current magnitudes are measured and compared to detect the rotor position. The prototype controller was simulated, fabricated, and tested in laboratory and experimental results of the proposed SRM drive system are presented. The new configuration enables the motor for self-starting without any other mechanism or starting device.
Research on Switched Reluctance Motor for Automobile Starter/Generator System
QUAN Li; LIU Qiang; ZHAO De-an; LIU Di-ji
2006-01-01
A self-designed and developed 12/10 switched reluctance motor(SRM)is chosen as the object of study and a prototype of 2.5 kW switched reluctance starter/generator with fly-wheel is designed based on the requirements of the selected engine (Changan Aotooc three-cylinder engine wagon) for the starter, generator and drive. The 36 V/42 V DC source system is applied to establishing the simulation-analyzing model of the motor. A finite-element (FE) analysis of its two-dimensional electromagnetic field is conducted to obtain the exact model of the motor. Systematic simulation is carried out combining with its power conversion circuit and control element. Meanwhile the starting process and performance of the system are studied and analyzed with special efforts. Satisfactory result is derived from the testing of the prototype:theoretical analysis is basically matched with the tested data, which proves the rationality and feasibility of the design procedures, systematic modeling and control strategies. Therefore, the new 12/10-structure scheme is put forward based on the development and analysis of various SRM and it meets the requirements of the researched motor in terms of the structural parameters.
Reduction of current chopping noise with DSP controller in switched reluctance motor drive system
郭伟; 詹琼华; 马志源
2002-01-01
A novel current chopping mode was used in a switched reluctance motor drive system to make full use of the characteristics of digital signal processor (DSP) TMS320F240. The necessity of this 180° phase-shift current control (PSCC) mode is introduced first and then the principle of PSCC covering both hardware requirement and software programming is described in detail. The analysis made indicated that with this mode, the chopping frequency in winding can reach 20 kHz with 10 kHz power switches and the control frequency can reach 40 kHz at the same time. Subsequently, based on the linear and nonlinear mathematical models of the switched reluctance motor ( SRM), some simulation work has been done. The simulation results show that when this mode is applied to SRM drive (SRD) system, the current waveform becomes better. So the ripple of the torque is reduced simultaneously and the vibration and acoustic noise are reduced involuntarily. Stationary tests show that the acoustic noise is greatly diminished. Finally, some experiments were made using a 50 kW SRD system for electric vehicle (EV). Experimental results indicate that this mode can be implemented feasibly and it has a good action on the SRD system.
A Novel Approach to the Design of Axial-Flux Switched-Reluctance Motors
Tim Lambert
2015-03-01
Full Text Available This paper presents the design of a new axial-flux switched-reluctance motor (AFSRM topology for in-wheel drive vehicle applications. The features of the topology include a short flux path and an outer-rotor configuration. The proposed topology also uses a sintered-lamellar soft magnetic composite core material, and permits displacement of the rotor along the suspension axis, which reduces damage to the stator caused by impacts and vibrations. The combination of these features makes this new topology competitive with other in-wheel motors in regard to torque density, durability, and cost. To describe the behaviour of the topology, a model of the topology is developed using a new integral inductance function. That model is used to select the design parameters of an 8/6 AFSRM, for which a fuzzy controller is also developed to control the phase current. Several simulations of the 8/6 AFSRM are performed to calculate its energy conversion efficiency, thermal performance, and torque density, and results indicate that the new AFSRM has a higher energy conversion efficiency, and can produce more torque/kg than other switched-reluctance motors used for in-wheel drive vehicle applications.
Dual-scale multimedia dynamic synchronization model
李乃祥
2009-01-01
Multimedia synchronization is the key technology in application of distributed multimedia.Solution of synchronization conflicts insides and among streams as well as that of user interaction,synchronization granularity refinement and synchronization precision improvement remain great challenges although great efforts have been invested by the academic circle.The construction method of a dual-scale dynamic synchronous model of multimedia presented in this article realizes multimedia synchronization on two sca...
Pereira, A.; Vega, J.
2005-07-01
The Asynchronous Event Distribution System (AEDS) was built to provides synchronization resources within the TJ-II local area network. It is a software system developed to add soft synchronization capabilities to the TJ-II data acquisition, control and analysis environments Soft synchronization signifies that AEDS is not a realtime system. In fact, AEDS is based on TCP/IP over ETHERNET networks. However, its response time is adequate for practical purposes when synchronization requirements can support some delay between event dispatch and message reception. Event broadcasters (or synchronization servers in AEDS terminology) are Windows computers. Destination computers (or synchronization clients) were also Windows machines in the first version of AEDS. However, this fact imposed a very important limitation on synchronization capabilities. to overcome this situation, synchronization clients for different environments have been added to AEDS: time-sharing operating systems (UNIX and LINUX), real-time operating systems (OS9 and VxWorks) and Java applications. The synchronization primitives that operate in these systems are very different between them and therefore, several approaches were chosen in order to provide the same functionality to the various environments. POSLX thread library with its basic synchronization primitives (mutex and conditions variables) was used to accomplish this task on UNIX/LINUX systems, IPC mechanisms for concurrent processes on OS9 and VxWorks real time operating systems, and synchronized-wait/notify primitives on Java virtual machines. (Author) 11 refs.
Transition to complete synchronization via near-synchronization in two coupled chaotic neurons
Wang Qing-Yun; Lu Qi-Shao; Wang Hai-Xia
2005-01-01
The synchronization transition in two coupled chaotic Morris-Lecar (ML) neurons with gap junction is studied with the coupling strength increasing. The conditional Lyapunov exponents, along with the synchronization errors are calculated to diagnose synchronization of two coupled chaotic ML neurons. As a result, it is shown that the increase in the coupling strength leads to incoherence, then induces a transition process consisting of three different synchronization states in succession, namely, burst synchronization, near-synchronization and embedded burst synchronization, and achieves complete synchronization of two coupled neurons finally. These sequential transitions to synchronization reveal a new transition route from incoherence to complete synchronization in coupled systems with multi-time scales.
Ayer, Lynsay; Ramchand, Rajeev; Geyer, Lily; Burgette, Lane; Kofner, Aaron
2016-06-01
The Army and Marine Corps have consistently experienced the highest rates of suicide relative to the other services. In both the Army and Marine Corps, the service members responsible for identifying and referring individuals at risk for suicide are called "gatekeepers" and are typically noncommissioned officers (NCOs). We used structural equation modeling on survey responses from 1184 Army soldiers and 796 marines to estimate the relationships between training, intervention efficacy, reluctance, and mental health stigma on NCO intervention behaviors. Efficacy and reluctance were independently associated with intervention behaviors, and stigma was only associated with intervention behaviors among Army NCOs. Study results suggest that while quantity of training may help NCOs feel more confident about their ability to intervene, other efforts such as changing training content and delivery mode (e.g., interactive vs. didactic training) may be necessary in order to reduce reluctance and stigma to intervene with service members at risk for suicide.
Vector control of three-phase AC machines system development in the practice
Quang, Nguyen Phung
2008-01-01
Covers the area of vector control of 3-phase AC machines, in particular induction motors with squirrel-cage rotor, permanent excited synchronous motors and doubly-fed induction machines. This title summarizes the basic structure of a field-oriented controlled 3-phase AC drive and grid voltage orientated controlled wind power plant.
Nutritional recommendations for synchronized swimming.
Robertson, Sherry; Benardot, Dan; Mountjoy, Margo
2014-08-01
The sport of synchronized swimming is unique, because it combines speed, power, and endurance with precise synchronized movements and high-risk acrobatic maneuvers. Athletes must train and compete while spending a great amount of time underwater, upside down, and without the luxury of easily available oxygen. This review assesses the scientific evidence with respect to the physiological demands, energy expenditure, and body composition in these athletes. The role of appropriate energy requirements and guidelines for carbohydrate, protein, fat, and micronutrients for elite synchronized swimmers are reviewed. Because of the aesthetic nature of the sport, which prioritizes leanness, the risks of energy and macronutrient deficiencies are of significant concern. Relative Energy Deficiency in Sport and disordered eating/eating disorders are also of concern for these female athletes. An approach to the healthy management of body composition in synchronized swimming is outlined. Synchronized swimmers should be encouraged to consume a well-balanced diet with sufficient energy to meet demands and to time the intake of carbohydrate, protein, and fat to optimize performance and body composition. Micronutrients of concern for this female athlete population include iron, calcium, and vitamin D. This article reviews the physiological demands of synchronized swimming and makes nutritional recommendations for recovery, training, and competition to help optimize athletic performance and to reduce risks for weight-related medical issues that are of particular concern for elite synchronized swimmers.
Permanent Magnet Synchronous Condenser with Solid State Excitation: Preprint
Hsu, P.; Muljadi, E.; Wu, Z.; Gao, W.
2015-04-07
A typical synchronous condenser (SC) consists of a free-spinning, wound-field synchronous generator and a field excitation controller. In this paper, we propose an SC that employs a permanent magnet synchronous generator (PMSG) instead of a wound-field machine. PMSGs have the advantages of higher efficiency and reliability. In the proposed configuration, the reactive power control is achieved by a voltage converter controller connected in series to the PMSG. The controller varies the phase voltage of the PMSG and creates the same effect on the reactive power flow as that of an over- or underexcited wound-field machine. The controller’s output voltage magnitude controls the amount of the reactive power produced by the SC. The phase of the controller’s output is kept within a small variation from the grid voltage phase. This small phase variation is introduced so that a small amount of power can be drawn from the grid into the controller to maintain its DC bus voltage. Because the output voltage of the controller is only a fraction of the line voltage, its VA rating is only a fraction of the rating of the PMSG. The proposed scheme is shown to be effective by computer simulations.
Synchronization in an evolving network
Singh, R K
2015-01-01
In this work we study the dynamics of Kuramoto oscillators on a stochastically evolving network whose evolution is governed by the phases of the individual oscillators and degree distribution. Synchronization is achieved after a threshold connection density is reached. This cumulative effect of topology and dynamics has many real-world implications, where synchronization in a system emerges as a collective property of its components in a self-organizing manner. The synchronous state remains stable as long as the connection density remains above the threshold value, with additional links providing resilience against network fluctuations.
Mosallanejad, Ali; Shoulaie, Abbas
2011-07-01
This paper reports a study of coil inductance profile in all positions of plunger in tubular linear reluctance motors (TLRMs) with open type magnetic circuits. In this paper, maximum inductance calculation methods in winding of tubular linear reluctance motors are described based on energy method. Furthermore, in order to calculate the maximum inductance, equivalent permeability is measured. Electromagnetic finite-element analysis for simulation and calculation of coil inductance in this motor is used. Simulation results of coil inductance calculation using 3-D FEM with coil current excitation is compared to theoretical and experimental results. The comparison yields a good agreement.
Dimitar Spirov
2005-10-01
Full Text Available Two-phase induction machine dynamic model in a coordinate system which rotates at synchronous speed and one-mass dynamic model of mechanism driven in relative units describing transient processes when starting an induction machine in case of constant load conditions are developed.The influence of equivalent circuit parameters of induction machine and mechanism parameters on impact currents and torques and starting time of common used induction machines is studied by means of design of experiment method.
Automation of printing machine
Sušil, David
2016-01-01
Bachelor thesis is focused on the automation of the printing machine and comparing the two types of printing machines. The first chapter deals with the history of printing, typesettings, printing techniques and various kinds of bookbinding. The second chapter describes the difference between sheet-fed printing machines and offset printing machines, the difference between two representatives of rotary machines, technological process of the products on these machines, the description of the mac...
Power balance considerations for brushless doubly-fed machines
Gorti, B.V.; Alexander, G.C.; Spee, R. [Oregon State Univ., Corvalis, OR (United States). Dept. of Electrical and Computer Engineering
1996-12-01
This paper discusses the power balances in a Brushless Doubly-Fed Machine (BDFM). Equations of power in the two stator windings and the rotor circuit, showing the distribution of electrical and mechanical powers in the air-gap, are obtained in two different speed ranges of BDFM synchronous mode operation. Comparisons vis-a-vis power distribution are made between the Wound-Rotor Induction machine (WRIM) and the BDFM. A brief analysis of the power balances, along with experimental data points obtained using a laboratory prototype machine, are given.
Transient-based analysis for the detection of broken damper bars in synchronous motors
Antonino-Daviu, J. A.; Climente-Alarcón, V.; Pons-Llinares, J.; Puche, R.; Pineda-Sánchez, M.
2013-01-01
Synchronous generators and motors constitute critical elements in power generation plants and certain industrial facilities. Damper bars are crucial components of most of these synchronous machines. They enable, among other functions, the direct-on-line starting of these machines, just as if they were asynchronous. Some recent cases, reported by several authors, have demonstrated that eventual failure of damper bars is possible, mainly due to the currents and stresses rising during their operation. In this context, the development of reliable techniques able to diagnose possible damper breakages has attracted significant interest within the fault diagnosis area. The present paper proposes the application of a novel transient-based methodology to diagnose broken damper bars in synchronous motors. This methodology was previously assessed with success in industrial induction motors with diverse sizes. The approach relies on the analysis of the stator startup current demanded by the machine during a direct-on-line starting. To this end, suitable time-frequency decomposition tools are used. In this particular work, the Discrete Wavelet Transform (DWT) is proposed, due to its simplicity, low computational requirements and easy interpretation of its results. Simulation and experimental results obtained with laboratory synchronous machines confirm the validity of the approach for condition monitoring of such windings.
Rowe, Robert
2002-05-01
The training of musicians begins by teaching basic musical concepts, a collection of knowledge commonly known as musicianship. Computer programs designed to implement musical skills (e.g., to make sense of what they hear, perform music expressively, or compose convincing pieces) can similarly benefit from access to a fundamental level of musicianship. Recent research in music cognition, artificial intelligence, and music theory has produced a repertoire of techniques that can make the behavior of computer programs more musical. Many of these were presented in a recently published book/CD-ROM entitled Machine Musicianship. For use in interactive music systems, we are interested in those which are fast enough to run in real time and that need only make reference to the material as it appears in sequence. This talk will review several applications that are able to identify the tonal center of musical material during performance. Beyond this specific task, the design of real-time algorithmic listening through the concurrent operation of several connected analyzers is examined. The presentation includes discussion of a library of C++ objects that can be combined to perform interactive listening and a demonstration of their capability.
Incoherence-Mediated Remote Synchronization
Zhang, Liyue; Motter, Adilson E.; Nishikawa, Takashi
2017-04-01
In previously identified forms of remote synchronization between two nodes, the intermediate portion of the network connecting the two nodes is not synchronized with them but generally exhibits some coherent dynamics. Here we report on a network phenomenon we call incoherence-mediated remote synchronization (IMRS), in which two noncontiguous parts of the network are identically synchronized while the dynamics of the intermediate part is statistically and information-theoretically incoherent. We identify mirror symmetry in the network structure as a mechanism allowing for such behavior, and show that IMRS is robust against dynamical noise as well as against parameter changes. IMRS may underlie neuronal information processing and potentially lead to network solutions for encryption key distribution and secure communication.
Synchronous identification of friendly targets
Telle, John M.; Roger, Stutz A.
1998-01-01
A synchronous communication targeting system for use in battle. The present invention includes a transceiver having a stabilizing oscillator, a synchronous amplifier and an omnidirectional receiver, all in electrical communication with each other. A remotely located beacon is attached to a blackbody radiation source and has an amplitude modulator in electrical communication with a optical source. The beacon's amplitude modulator is set so that the optical source transmits radiation frequency at approximately the same or lower amplitude than that of the blackbody radiation source to which the beacon is attached. The receiver from the transceiver is adapted to receive frequencies approximately at or below blackbody radiation signals and sends such signals to the synchronous amplifier. The synchronous amplifier then rectifies and amplifies those signals which correspond to the predetermined frequency to therefore identify whether the blackbody radiation source is friendly or not.
How to suppress undesired synchronization
Louzada, V H P; Andrade, J S; Herrmann, H J
2012-01-01
It is delightful to observe the emergence of synchronization in the blinking of fireflies to attract partners and preys. Other charming examples of synchronization can also be found in a wide range of phenomena such as, e.g., neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in communication networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge of the system, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement in mitigation is observed when contrarians sit at the highly connected ele...
G. Venkatesan
2006-01-01
Full Text Available This study presents a novel Switched Reluctance Motor (SRM drive system with power factor improvement. Recently, many of the converters with variable speed drives have no input power factor correction circuits. This results in harmonic pollution of the utility supply, which should be avoided. The effect of power factor variation in terms of harmonic content is also analyzed in this study. The different operations like single pulse, soft chopping and hard chopping modes are done with and without a power factor controller. This study describes the buck - boost converter topology with above said methods for SRM drive. The boost converter is used to improve the input sinusoidal current and the buck converter is used to regulate the dc source voltage. The proposed topologies were simulated using MATLAB / Simulink software package and the results were obtained. The computer simulation results support the proposed methods.
Self-tuning fuzzy logic control of a switched reluctance generator for wind energy applications
Park, Kiwoo; Chen, Zhe
2012-01-01
This paper presents a new self-tuning fuzzy logic control (FLC) based speed controller of a switched reluctance generator (SRG) for wind power applications. Due to its doubly salient structure and magnetic saturation, the SRG possesses an inherent characteristic of strong nonlinearity. In addition...... has better adaptability than a traditional controller so that it provides better performance over a wide range of operating conditions. The current controller is basically a hysteresis controller which controls the phase current in accordance with the turn-on and turn-off angles. Simulation results......, its flux linkage, inductance, and torque are highly coupled with the rotor position and phase current. All these features make the application of traditional controllers to the SRG difficult and unsatisfactory. The proposed controller consists of three main parts: turn-on and turn-off angle...
Sensorless Control of Low-cost Single-phase Hybrid Switched Reluctance Motor Drive
Jakobsen, Uffe; Lu, Kaiyuan; Rasmussen, Peter Omand
2015-01-01
This paper presents a sensorless-controlled, low-cost, low-power, and variable-speed drive system suitable for fan and pump applications. The main advantages of this drive system are the low system cost, simple converter structure, and simple but robust sensorless control technique. The drive motor...... is a special hybrid switched reluctance motor. The proposed sensorless control method beneficially utilizes the stator side PM field and its performance is motor parameter independent. The unique low-cost drive system solution, simple and robust sensorless control features of this drive system, is demonstrated...... in detail in this paper. Important design details for practical implementation of the sensorless control algorithm are included. The complete drive system performance is validated using a prototype drive system....
Sensorless control of low-cost single-phase hybrid switched reluctance motor drive
Jakobsen, Uffe; Lu, Kaiyuan; Rasmussen, Peter Omand
2013-01-01
This paper presents a sensorless-controlled, low-cost, low-power, variable-speed drive system suitable for fan and pump applications. The main advantages of this drive system are the low system cost, simple converter structure, and simple but robust sensorless control technique. The drive motor...... is a special Hybrid Switched Reluctance Motor (HSRM). The proposed sensorless control method utilizes beneficially the stator side permanent magnet field and its performance is motor parameter independent. The unique low-cost drive system solution, simple and robust sensorless control features of this drive...... system, is demonstrated in detail in this paper. Important design details for practical implementation of the sensorless control algorithm are included. The complete drive system performance is validated using a prototype drive system....
Efficiency Enhancement of a Low-Voltage Automotive Vacuum Cleaner Using a Switched Reluctance Motor
Han-Geol Seon
2016-08-01
Full Text Available A recent increase in the number of diverse leisure activities and family outdoor activities has increased the need for the automobile-embedded vacuum cleaner. To date, this technology has not been applied in Korea and development efforts are not underway. Many of the existing portable cleaners connecting to the lighter jack of the vehicle use a direct current motor (DC motor. However, they do not have sufficient suction power to satisfy consumers; moreover, they have low durability and efficiency. In this paper, we therefore propose a technology for increasing the efficiency of the low-voltage automobile vacuum cleaner by replacing the existing DC motor with a switched reluctance motor (SRM, which has superior durability and efficiency.
Direct Instantaneous Torque Control of 4 Phase 8/6 Switched Reluctance Motor
Srinivas Pratapgiri
2011-10-01
Full Text Available The applications of Switched Reluctance Motor Drives has increased in the recent past because of advantages like simple structure, no rotor winding, high torque to weight ratio, adaptability to harsh environments like coal mining etc. But the main disadvantage is that torque ripple is high because of the double saliency. This paper presents a high dynamic control technique called Direct Instantaneous Torque Control (DITC where in the torque is maintained within a hysteresis band by changing the switching states of the phases between 1, 0 or -1.Thus torque ripple minimization is an inherent property of DITC. DITC based SRM drive is simulated in MATLAB/SIMULINK environment and results are discussed elaborately
Sensorless control of low-cost single-phase hybrid switched reluctance motor drive
Jakobsen, Uffe; Lu, Kaiyuan; Rasmussen, Peter Omand;
2013-01-01
This paper presents a sensorless-controlled, low-cost, low-power, variable-speed drive system suitable for fan and pump applications. The main advantages of this drive system are the low system cost, simple converter structure, and simple but robust sensorless control technique. The drive motor...... is a special Hybrid Switched Reluctance Motor (HSRM). The proposed sensorless control method utilizes beneficially the stator side permanent magnet field and its performance is motor parameter independent. The unique low-cost drive system solution, simple and robust sensorless control features of this drive...... system, is demonstrated in detail in this paper. Important design details for practical implementation of the sensorless control algorithm are included. The complete drive system performance is validated using a prototype drive system....
Nonlinear Speed Control of Switched Reluctance Motor Drives Taking into Account Mutual Inductance
M. Alrifai
2008-01-01
Full Text Available A speed control algorithm is proposed for variable speed switched reluctance motor (SRM drives taking into account the effects of mutual inductances. The control scheme adopts two-phase excitation; exciting two adjacent phases can overcome the problems associated with single-phase excitation such as large torque ripple, increased acoustic noise, and rotor shaft fatigues. The effects of mutual coupling between two adjacent phases and their contribution to the generated electromagnetic torque are considered in the design of the proposed control scheme for the motor. The proposed controller guarantees the convergence of the currents and the rotor speed of the motor to their desired values. Simulation results are given to illustrate the developed theory; the simulation studies show that the proposed controller works well. Moreover, the simulation results indicate that the proposed controller is robust to changes in the parameters of the motor and to changes in the load torque.
Dehkordi, Behzad Mirzaeian, E-mail: mirzaeian@eng.ui.ac.i [Department of Electrical Engineering, Faculty of Engineering, University of Isfahan, Hezar-Jerib St., Postal code 8174673441, Isfahan (Iran, Islamic Republic of); Parsapoor, Amir, E-mail: amirparsapoor@yahoo.co [Department of Electrical Engineering, Faculty of Engineering, University of Isfahan, Hezar-Jerib St., Postal code 8174673441, Isfahan (Iran, Islamic Republic of); Moallem, Mehdi, E-mail: moallem@cc.iut.ac.i [Department of Electrical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Lucas, Caro, E-mail: lucas@ut.ac.i [Centre of Excellence for Control and Intelligent Processing, Electrical and Computer Engineering Faculty, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)
2011-01-15
In this paper, a brain emotional learning based intelligent controller (BELBIC) is developed to control the switched reluctance motor (SRM) speed. Like other intelligent controllers, BELBIC is model free and is suitable to control nonlinear systems. Motor parameter changes, operating point changes, measurement noise, open circuit fault in one phase and asymmetric phases in SRM are also simulated to show the robustness and superior performance of BELBIC. To compare the BELBIC performance with other intelligent controllers, Fuzzy Logic Controller (FLC) is developed. System responses with BELBIC and FLC are compared. Furthermore, by eliminating the position sensor, a method is introduced to estimate the rotor position. This method is based on Adaptive Neuro Fuzzy Inference System (ANFIS). The estimator inputs are four phase flux linkages. Suggested rotor position estimator is simulated in different conditions. Simulation results confirm the accurate rotor position estimation in different loads and speeds.
Principles of synchronous digital hierarchy
Jain, Rajesh Kumar
2012-01-01
The book presents the current standards of digital multiplexing, called synchronous digital hierarchy, including analog multiplexing technologies. It is aimed at telecommunication professionals who want to develop an understanding of digital multiplexing and synchronous digital hierarchy in particular and the functioning of practical telecommunication systems in general. The text includes all relevant fundamentals and provides a handy reference for problem solving or defining operations and maintenance strategies. The author covers digital conversion and TDM principles, line coding and digital
Chaotic synchronization via linear controller
Chen Feng-Xiang; Zhang Wei-Dong
2007-01-01
A technical framework of constructing a linear controller for chaotic synchronization by utilizing the stability theory of cascade-connected system is presented. Based on the method developed in the paper, two simple and linear feedback controllers, as examples, are derived for the synchronization of Liu chaotic system and Duffing oscillator, respectively.This method is quite flexible in constructing a control law. Its effectiveness is also illustrated by the simulation results.
Synchronized Swimming of Two Fish
Koumoutsakos, Petros; Novati, Guido; Abbati, Gabriele; Hejazialhosseini, Babak; van Rees, Wim
2015-11-01
We present simulations of two, self-propelled, fish-like swimmers that perform synchronized moves in a two-dimensional, viscous fluid. The swimmers learn to coordinate by receiving a reward for their synchronized actions. We analyze the swimming patterns emerging for different rewards in terms of their hydrodynamic efficiency and artistic impression. European Research Council (ERC) Advanced Investigator Award (No. 2-73985-14).
Photonic Cavity Synchronization of Nanomechanical Oscillators
Bagheri, Mahmood; Poot, Menno; Fan, Linran; Marquardt, Florian; Tang, Hong X.
2013-01-01
Synchronization in oscillatory systems is a frequent natural phenomenon and is becoming an important concept in modern physics. Nanomechanical resonators are ideal systems for studying synchronization due to their controllable oscillation properties and engineerable nonlinearities. Here we demonstrate synchronization of two nanomechanical oscillators via a photonic resonator, enabling optomechanical synchronization between mechanically isolated nanomechanical resonators. Optical backaction gi...
Selection for reluctance to avoid humans during the domestication of mice.
Goto, T; Tanave, A; Moriwaki, K; Shiroishi, T; Koide, T
2013-11-01
Many animal species have been domesticated over the course of human history and became tame as a result of domestication. Tameness is a behavioral characteristic with 2 potential components: (1) reluctance to avoid humans and (2) motivation to approach humans. However, the specific behavioral characteristics selected during domestication processes remain to be clarified for many species. To quantify these 2 different components of tameness separately, we established 3 behavioral tests: the 'active tame', 'passive tame' and 'stay-on-hand' tests. We subjected genetically diverse mouse strains to these tests, including 10 wild strains (BFM/2Ms, PGN2/Ms, HMI/Ms, BLG2/Ms, NJL/Ms, KJR/Ms, SWN/Ms, CHD/Ms, MSM/Ms and CAST/Ei), a fancy strain (JF1/Ms) and 6 standard laboratory strains (C3H/HeNJcl, CBA/J, BALB/cAnNCrlCrlj, DBA/2JJcl, 129(+Ter) /SvJcl and C57BL/6JJcl). To analyze the effects of domestication, these 17 strains were divided into 2 groups: domesticated strains (fancy and laboratory strains) and wild strains. Significant differences between strains were observed in all traits, and the calculated estimates of broad-sense heritability were 0.15-0.72. These results illustrate that tameness in mice is significantly influenced by genetic background. In addition, they clearly show the differences in the features of tameness in domesticated and wild strains. Most of the domesticated strains showed significantly greater reluctance to avoid humans than wild strains, whereas there was no significant difference in the level of motivation to approach humans between these 2 groups. These results might help to clarify the genetic basis of tameness in mice.
VOLTAGE REGULATORS OF SYNCHRONOUS GENERATORS
Grigorash O. V.
2015-06-01
Full Text Available Synchronous generators are the primary source of electrical power autonomous electrosupply systems, including backup systems. They are also used in a structure of rotating electricity converters and are widely used in renewable energy as part of wind power plants of small, mini and micro hydroelectric plants. Increasing the speed and the accuracy of the system of the voltage regulation of synchronous generators is possible due to the development of combined systems containing more stabilizers. The article illustrates the functional schemes of circuit voltage stabilizers and frequency synchronous generators (with electromagnetic excitation and permanent magnet excitation and describes the features of their work, including two and three-aggregate rotating converters of electricity used in uninterruptible power supply systems. To improve the technical characteristics of the system of stabilization we have proposed functional solutions for stabilizers of synchronous generators made on the base of direct frequency converters and using a transformer with a rotating magnetic field. To improve the reliability of and to improve the operational characteristics of the autonomous independent sources of electricity we suggest creating the main functional blocks and the elements of the stabilization system in a modular way. The functional circuit solutions of voltage regulators of synchronous generators and the characteristics of their work considered in the article, are able to improve the efficiency of pre-design work in the development of new technical solutions for stabilizing the voltage and the frequency in synchronous generators of electrosupply autonomous systems
Computer-aided design studies of the homopolar linear synchronous motor
Dawson, G. E.; Eastham, A. R.; Ong, R.
1984-09-01
The linear induction motor (LIM), as an urban transit drive, can provide good grade-climbing capabilities and propulsion/braking performance that is independent of steel wheel-rail adhesion. In view of its 10-12 mm airgap, the LIM is characterized by a low power factor-efficiency product of order 0.4. A synchronous machine offers high efficiency and controllable power factor. An assessment of the linear homopolar configuration of this machine is presented as an alternative to the LIM. Computer-aided design studies using the finite element technique have been conducted to identify a suitable machine design for urban transit propulsion.
Electrical machines mathematical fundamentals of machine topologies
Gerling, Dieter
2015-01-01
Electrical Machines and Drives play a powerful role in industry with an ever increasing importance. This fact requires the understanding of machine and drive principles by engineers of many different disciplines. Therefore, this book is intended to give a comprehensive deduction of these principles. Special attention is given to the precise mathematical derivation of the necessary formulae to calculate machines and drives and to the discussion of simplifications (if applied) with the associated limits. The book shows how the different machine topologies can be deduced from general fundamentals, and how they are linked together. This book addresses graduate students, researchers, and developers of Electrical Machines and Drives, who are interested in getting knowledge about the principles of machine and drive operation and in detecting the mathematical and engineering specialties of the different machine and drive topologies together with their mutual links. The detailed - but nevertheless compact - mat...
EXPERIENCE WITH SYNCHRONOUS GENERATOR MODEL USING PARTICLE SWARM OPTIMIZATION TECHNIQUE
N.RATHIKA
2014-07-01
Full Text Available This paper intends to the modeling of polyphase synchronous generator and minimization of power losses using Particle swarm optimization (PSO technique with a constriction factor. Usage of Polyphase synchronous generator mainly leads to the total power circulation in the system which can be distributed in all phases. Another advantage of polyphase system is the fault at one winding does not lead to the system shutdown. The Process optimization is the chastisement of adjusting a process so as to optimize some stipulated set of parameters without violating some constraint. Accurate value can be extracted using PSO and it can be reformulated. Modeling and simulation of the machine is executed. MATLAB/Simulink has been cast-off to implement and validate the result.
Multivariable nonlinear control of STATCOM for synchronous generator stabilization
Sahoo, N.C. [Multimedia Univ., Melaka (Malaysia). Faculty of Engineering and Technology; Panigrahi, B.K.; Panda, G. [Multimedia Univ., Selangor (Malaysia); Dash, P.K. [National Inst. of Technology, Rourkela (India)
2004-01-01
A static synchronous compensator (STATCOM) is a typical flexible ac transmission system device playing a vital role as a stability aid for small and large transient disturbances in an interconnected power system. This article deals with design and evaluation of a feedback linearizing nonlinear controller for STATCOM installed in a single-machine infinite-bus power system. In addition to the coordinated control of ac and dc bus voltages, the proposed controller also provides good damping to the electromechanical oscillation of the synchronous generator under transient disturbances. The efficiency of the control strategy is evaluated by computer simulation studies. The comparative study of these results with the conventional cascade control structure establishes the elegance of the proposed control scheme. (author)
Laser machining of advanced materials
Dahotre, Narendra B
2011-01-01
Advanced materialsIntroductionApplicationsStructural ceramicsBiomaterials CompositesIntermetallicsMachining of advanced materials IntroductionFabrication techniquesMechanical machiningChemical Machining (CM)Electrical machiningRadiation machining Hybrid machiningLaser machiningIntroductionAbsorption of laser energy and multiple reflectionsThermal effectsLaser machining of structural ceramicsIntrodu
Unidirectional synchronization of Hodgkin-Huxley neurons
Cornejo-Perez, Octavio [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: octavio@ipicyt.edu.mx; Femat, Ricardo [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: rfemat@ipicyt.edu.mx
2005-07-01
Synchronization dynamics of two noiseless Hodgkin-Huxley (HH) neurons under the action of feedback control is studied. The spiking patterns of the action potentials evoked by periodic external modulations attain synchronization states under the feedback action. Numerical simulations for the synchronization dynamics of regular-irregular desynchronized spiking sequences are displayed. The results are discussed in context of generalized synchronization. It is also shown that the HH neurons can be synchronized in face of unmeasured states.
Impulsive Synchronization of Discrete Chaotic Systems
郑永爱; 年漪蓓; 刘曾荣
2003-01-01
Impulsive synchronization of two chaotic maps is reformulated as impulsive control of the synchronization error system. We then present a theorem on the asymptotic synchronization of two chaotic maps by using synchronization impulses with varying impulsive intervals. As an example and application of the theorem, we derives some sufficient conditions for the synchronization of two chaotic Lozi maps via impulsive control. The effectiveness of this approach has been demonstrated with chaotic Lozi map.
Impulsive Synchronization of Laser Plasma System
LI Yang; LIAO Xiao-Feng; LI Chuan-Dong; CHEN Guo
2007-01-01
The issue of impulsive synchronization of the coupled chaotic laser plasma system is investigated. A new framework for impulsive synchronization of such chaotic systems is presented, which makes the synchronization error system a linear impulsive control system. We derive some sufficient conditions for the synchronization of a laser plasma system via impulsive control with the varying impulsive intervals, which allows us to derive the impulsive synchronization law easily. To illustrate the effectiveness of the proposed results, two numerical examples are given.
Outer Synchronization of Complex Networks by Impulse
孙文; 燕子宗; 陈士华; 吕金虎
2011-01-01
This paper investigates outer synchronization of complex networks, especially, outer complete synchronization and outer anti-synchronization between the driving network and the response network. Employing the impulsive control method which is uncontinuous, simple, efficient, low-cost and easy to implement in practical applications, we obtain some sufficient conditions of outer complete synchronization and outer anti-synchronization between two complex networks. Numerical simulations demonstrate the effectiveness of the proposed impulsive control scheme.
Hybrid synchronization of hyperchaotic Lu system
K Sebastian Sudheer; M Sabir
2009-10-01
In this paper, we study the hybrid synchronization between two identical hyperchaotic Lu systems. Hybrid synchronization of hyperchaotic Lu system is achieved through synchronization of two pairs of states and anti-synchronization of the other two pairs of states. Active controls are designed to achieve hybrid synchronization between drive and response systems using the sum and difference of relevant variables of the chaotic systems. Numerical simulations are presented to evaluate the analysis and effectiveness of the controllers.
The deleuzian abstract machines
Werner Petersen, Erik
2005-01-01
production. In Kafka: Toward a Minor Literature, Deleuze and Guatari gave the most comprehensive explanation to the abstract machine in the work of art. Like the war-machines of Virilio, the Kafka-machine operates in three gears or speeds. Furthermore, the machine is connected to spatial diagrams...
Energy Conversion Loops for Flux-Switching PM Machine Analysis
E. Ilhan
2012-10-01
Full Text Available Induction and synchronous machines have traditionally been the first choice of automotive manufacturers for electric/hybrid vehicles. However, these conventional machines are not able anymore to meet the increasing demands for a higher energy density due to space limitation in cars. Flux-switching PM (FSPM machines with their high energy density are very suitable to answer this demand. In this paper, the energy conversion loop technique is implemented on FSPM for the first time. The energy conversion technique is a powerful tool for the visualization of machine characteristics, both linear and nonlinear. Further, the technique provides insight into the torque production mechanism. A stepwise explanation is given on how to create these loops for FSPM along with the machine operation.
Synchronous Pendulums and Aliasing
Jia-Cherng Chong
2014-12-01
Full Text Available We present the construction, mathematical relation and simulation of a 16-bob pendulum wave machine (PWM. Following small angle approximation, the PWM is a useful teaching aid to demonstrate free oscillations and periodic motion; it can also illustrate effects of aliasing in physics and engineering. The duration of pattern cycle is adjusted with a set of pendulum lengths that are dictated by a non-linear function followed by the outline of the PWM design aspects. Normal 0 false false false EN-GB X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}
Simplified Model of Brushless Synchronous Generator for Real Time Simulation
Lopez, M D; Rebollo, E; Blanquez, F R
2015-01-01
This paper presents a simplified model of brushless synchronous machine for saving hardware resources in a real time simulation system. Firstly, a brushless excitation system model is described. Thereafter, the simplified transfer function of an AC exciter and rotating diodes of the brushless excitation system is estimated. Finally, the complete system is simulated, comparing the main generator's voltage with both detailed and simplified excitation systems in several scenarios. These results show the accuracy of the simplified model against the detailed simulation model, resulting on an important hardware resources savings.
Bodily Synchronization Underlying Joke Telling
R. C. Schmidt
2014-08-01
Full Text Available Advances in video and time series analysis have greatly enhanced our ability to study the bodily synchronization that occurs in natural interactions. Past research has demonstrated that the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. The present study investigated how the bodily synchronization in a joke telling task is spread across different nested temporal scales. Pairs of participants enacted knock-knock jokes and times series of their bodily activity were recorded. Coherence and relative phase analyses were used to evaluate the synchronization of bodily rhythms for the whole trial as well as at the subsidiary time scales of the whole joke, the setup of the punch line, the two-person exchange and the utterance. The analyses revealed greater than chance entrainment of the joke teller’s and joke responder’s movements at all time scales and that the relative phasing of the teller’s movements led those of the responder at the longer time scales. Moreover, this entrainment was greater when visual information about the partner’s movements was present but was decreased particularly at the shorter time scales when explicit gesturing in telling the joke was performed. In short, the results demonstrate that a complex interpersonal bodily dance occurs during structured conversation interactions and that this dance is constructed from a set of rhythms associated with the nested behavioral structure of the interaction.
ENGINEERING CHARACTERISTICS AND ITS MECHANISM EXPLANATION OF VIBRATORY SYNCHRONIZATION TRANSMISSION
Xiong Wanli; Wen Bangchun; Duan Zhishan
2004-01-01
Vibratory synchronization transmission (VST) is a kind of special physical phenomenon in inertia vibra-tion mechanical systems.For an inertia vibration mechanical system driven by one pair of motors runs in step,even the power supply of one motor is cut off,the motor can continue to keep rotating state under the vibration exciting of the machine body driven by only one other motor.And its rotating frequency will be the same as that of the other one.The transient process of this wonderful physical phenomenon has not been described quantitatively according to current-existing mechanical models.On the basis of investigation of the engineering characteristics of VST,a mechanical and electrical coupling mathematical model of a two-shaft inertia vibration machine is established.With this model,the transient process of VST is recurred quantitatively and successfully,and a reasonable explana-tion is given.
Huang, Chengdai; Cao, Jinde
2017-05-01
This paper is concerned with the issues of synchronization and anti-synchronization for fractional chaotic financial system with market confidence by taking advantage of active control approach. Some sufficient conditions are derived to guarantee the synchronization and anti-synchronization for the proposed fractional system. Moreover, the relationship between the order and synchronization(anti-synchronization) is demonstrated numerically. It reveals that synchronization(anti-synchronization) is faster as the order increases. Finally, two illustrative examples are exploited to verify the efficiency of the obtained theoretical results.
Simultaneous Synchronization and Anti-Synchronization of Two Identical New 4D Chaotic Systems
GUO Rong-Wei
2011-01-01
We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes, but also anti-synchronizes two identical new 4D chaotic systems. Numerical simulations verify the correctness and the effectiveness of the proposed theoretical results.%@@ We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes, but also anti-synchronizes two identical new 4D chaotic systems.Numerical simulations verify the correctness and the effectiveness of the proposed theoretical results.
Zhou, Dao; Blaabjerg, Frede; Franke, Toke
2015-01-01
of the low-speed (direct-drive) and medium-speed (one-stage) permanent-magnet synchronous generators are both promising solutions. This paper will assess and compare the reliability metrics for the machine-side converter for those two configurations. First, a translation from the mission profile......, according to the lifetime power cycles, the lifespan can be calculated when operating in various wind classes. It is concluded that, although the low-speed permanent-magnet synchronous generator is able to eliminate the gearbox, the lifespan of its machine-side converter is lower than the one-stage medium...
Agarlita, Sorin-Cristian; Boldea, Ion; Blaabjerg, Frede
2012-01-01
method is based on a state observer incorporating the “active flux” concept used to deliver RSM rotor position and speed information for medium and high speed range. Even if both methods perform successfully in separate speed regions, estimation of the two algorithms is combined as a sensor fusion...
Agarliţă, Sorin-Cristian; Boldea, I.; Blaabjerg, Frede
2011-01-01
method is based on a state observer incorporating the “active flux” concept used to deliver RSM rotor position and speed information for medium and high speed range. Even if both methods perform successfully in separate speed regions, estimation of the two algorithms is combined as a sensor fusion...
Kang, Dongwoo; Lee, Eonseok; Kim, Hyunchang; Choi, Young-Man; Lee, Seunghyun; Kim, Inyoung; Yoon, Dukkyun; Jo, Jeongdai; Kim, Bongmin; Lee, Taik-Min
2014-06-01
Offset printing processes are promising candidates for producing printed electronics due to their capacity for fine patterning and suitability for mass production. To print high-resolution patterns with good overlay using offset printing, the velocities of two contact surfaces, which ink is transferred between, should be synchronized perfectly. However, an exact velocity of the contact surfaces is unknown due to several imperfections, including tolerances, blanket swelling, and velocity ripple, which prevents the system from being operated in the synchronized condition. In this paper, a novel method of measurement based on the sticking model of friction force was proposed to determine the best synchronized condition, i.e., the condition in which the rate of synchronization error is minimized. It was verified by experiment that the friction force can accurately represent the rate of synchronization error. Based on the measurement results of the synchronization error, the allowable margin of synchronization error when printing high-resolution patterns was investigated experimentally using reverse offset printing. There is a region where the patterning performance is unchanged even though the synchronization error is varied, and this may be viewed as indirect evidence that printability performance is secured when there is no slip at the contact interface. To understand what happens at the contact surfaces during ink transfer, the deformation model of the blanket's surface was developed. The model estimates how much deformation on the blanket's surface can be borne by the synchronization error when there is no slip at the contact interface. In addition, the model shows that the synchronization error results in scale variation in the machine direction (MD), which means that the printing registration in the MD can be adjusted actively by controlling the synchronization if there is a sufficient margin of synchronization error to guarantee printability. The effect of
Synchronization in uncertain complex networks
Chen, Maoyin; Zhou, Donghua
2006-03-01
We consider the problem of synchronization in uncertain generic complex networks. For generic complex networks with unknown dynamics of nodes and unknown coupling functions including uniform and nonuniform inner couplings, some simple linear feedback controllers with updated strengths are designed using the well-known LaSalle invariance principle. The state of an uncertain generic complex network can synchronize an arbitrary assigned state of an isolated node of the network. The famous Lorenz system is stimulated as the nodes of the complex networks with different topologies. We found that the star coupled and scale-free networks with nonuniform inner couplings can be in the state of synchronization if only a fraction of nodes are controlled.
How to suppress undesired synchronization.
Louzada, V H P; Araújo, N A M; Andrade, J S; Herrmann, H J
2012-01-01
Examples of synchronization can be found in a wide range of phenomena such as neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement is observed when contrarians sit at the highly connected elements. The same qualitative results are obtained for artificially generated networks and two real ones, namely, the Routers of the Internet and a neuronal network.
Multicentric synchronous recurrent aggressive fibromatosis
Kavita Kohli
2012-01-01
Full Text Available Extra-abdominal desmoid tumors are known as aggressive fibromatosis (AFM. Synchronous and metachronous multicentric aggressive fibromatosis are rare lesions and pose dilemma in diagnosis and management. A rare and interesting case of recurrent multicentric, synchronous AFM is presented which to the best of our knowledge has not been reported earlier. A young male presented with well defined, hard, fixed swelling on the thigh. Resected tumor mass on histopathology was diagnosed as an extra abdominal fibromatosis. He presented again after two months with swelling at the same site; and two more swellings on the foot. Fine needle aspiration cytology (FNAC from all three sites was performed; and was suggestive of benign spindle cell lesion of fibrogenic origin with the possibility of multicentric synchronous recurrent aggressive fibromatosis.
Cluster synchronization in oscillatory networks
Belykh, Vladimir N.; Osipov, Grigory V.; Petrov, Valentin S.; Suykens, Johan A. K.; Vandewalle, Joos
2008-09-01
Synchronous behavior in networks of coupled oscillators is a commonly observed phenomenon attracting a growing interest in physics, biology, communication, and other fields of science and technology. Besides global synchronization, one can also observe splitting of the full network into several clusters of mutually synchronized oscillators. In this paper, we study the conditions for such cluster partitioning into ensembles for the case of identical chaotic systems. We focus mainly on the existence and the stability of unique unconditional clusters whose rise does not depend on the origin of the other clusters. Also, conditional clusters in arrays of globally nonsymmetrically coupled identical chaotic oscillators are investigated. The design problem of organizing clusters into a given configuration is discussed.
Phase Synchronization in Railway Timetables
Fretter, Christoph; Weihe, Karsten; Müller-Hannemann, Matthias; Hütt, Marc-Thorsten
2010-01-01
Timetable construction belongs to the most important optimization problems in public transport. Finding optimal or near-optimal timetables under the subsidiary conditions of minimizing travel times and other criteria is a targeted contribution to the functioning of public transport. In addition to efficiency (given, e.g., by minimal average travel times), a significant feature of a timetable is its robustness against delay propagation. Here we study the balance of efficiency and robustness in long-distance railway timetables (in particular the current long-distance railway timetable in Germany) from the perspective of synchronization, exploiting the fact that a major part of the trains run nearly periodically. We find that synchronization is highest at intermediate-sized stations. We argue that this synchronization perspective opens a new avenue towards an understanding of railway timetables by representing them as spatio-temporal phase patterns. Robustness and efficiency can then be viewed as properties of t...
Control of non-conventional synchronous motors
Louis, Jean-Paul
2013-01-01
Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,
SENSITIVE ERROR ANALYSIS OF CHAOS SYNCHRONIZATION
HUANG XIAN-GAO; XU JIAN-XUE; HUANG WEI; L(U) ZE-JUN
2001-01-01
We study the synchronizing sensitive errors of chaotic systems for adding other signals to the synchronizing signal.Based on the model of the Henon map masking, we examine the cause of the sensitive errors of chaos synchronization.The modulation ratio and the mean square error are defined to measure the synchronizing sensitive errors by quality.Numerical simulation results of the synchronizing sensitive errors are given for masking direct current, sinusoidal and speech signals, separately. Finally, we give the mean square error curves of chaos synchronizing sensitivity and threedimensional phase plots of the drive system and the response system for masking the three kinds of signals.
A Parameter Communication Optimization Strategy for Distributed Machine Learning in Sensors
Jilin Zhang
2017-09-01
Full Text Available In order to utilize the distributed characteristic of sensors, distributed machine learning has become the mainstream approach, but the different computing capability of sensors and network delays greatly influence the accuracy and the convergence rate of the machine learning model. Our paper describes a reasonable parameter communication optimization strategy to balance the training overhead and the communication overhead. We extend the fault tolerance of iterative-convergent machine learning algorithms and propose the Dynamic Finite Fault Tolerance (DFFT. Based on the DFFT, we implement a parameter communication optimization strategy for distributed machine learning, named Dynamic Synchronous Parallel Strategy (DSP, which uses the performance monitoring model to dynamically adjust the parameter synchronization strategy between worker nodes and the Parameter Server (PS. This strategy makes full use of the computing power of each sensor, ensures the accuracy of the machine learning model, and avoids the situation that the model training is disturbed by any tasks unrelated to the sensors.
A Parameter Communication Optimization Strategy for Distributed Machine Learning in Sensors.
Zhang, Jilin; Tu, Hangdi; Ren, Yongjian; Wan, Jian; Zhou, Li; Li, Mingwei; Wang, Jue; Yu, Lifeng; Zhao, Chang; Zhang, Lei
2017-09-21
In order to utilize the distributed characteristic of sensors, distributed machine learning has become the mainstream approach, but the different computing capability of sensors and network delays greatly influence the accuracy and the convergence rate of the machine learning model. Our paper describes a reasonable parameter communication optimization strategy to balance the training overhead and the communication overhead. We extend the fault tolerance of iterative-convergent machine learning algorithms and propose the Dynamic Finite Fault Tolerance (DFFT). Based on the DFFT, we implement a parameter communication optimization strategy for distributed machine learning, named Dynamic Synchronous Parallel Strategy (DSP), which uses the performance monitoring model to dynamically adjust the parameter synchronization strategy between worker nodes and the Parameter Server (PS). This strategy makes full use of the computing power of each sensor, ensures the accuracy of the machine learning model, and avoids the situation that the model training is disturbed by any tasks unrelated to the sensors.
Forced synchronization of quasiperiodic oscillations
Stankevich, N. V.; Kurths, J.; Kuznetsov, A. P.
2015-01-01
A model of a generator of quasiperiodic oscillations forced by a periodic pulse sequence is studied. We analyze synchronization when the autonomous generator demonstrates periodic, quasiperiodic, respective weakly chaotic oscillations. For the forced quasiperiodic oscillations a picture of synchronization, consisting of small-scale and large-scale structures was uncovered. It even includes the existence of stable the three-frequency tori. For the regime of weak chaos a partial destruction of this features and of the regime of three-frequency tori are found.
Hydraulic Power Plant Machine Dynamic Diagnosis
Hans Günther Poll
2006-01-01
Full Text Available A method how to perform an entire structural and hydraulic diagnosis of prototype Francis power machines is presented and discussed in this report. Machine diagnosis of Francis units consists on a proper evaluation of acquired mechanical, thermal and hydraulic data obtained in different operating conditions of several rotary and non rotary machine components. Many different physical quantities of a Francis machine such as pressure, strains, vibration related data, water flow, air flow, position of regulating devices and displacements are measured in a synchronized way so that a relation of cause an effect can be developed for each operating condition and help one to understand all phenomena that are involved with such kind of machine. This amount of data needs to be adequately post processed in order to allow correct interpretation of the machine dynamics and finally these data must be compared with the expected calculated data not only to fine tuning the calculation methods but also to accomplish fully understanding of the influence of the water passages on such machines. The way how the power plant owner has to operate its Francis machines, many times also determined by a central dispatcher, has a high influence on the fatigue life time of the machine components. The diagnostic method presented in this report helps one to understand the importance of adequate operation to allow a low maintenance cost for the entire power plant. The method how to acquire these quantities is discussed in details together with the importance of correct sensor balancing, calibration and adequate correlation with the physical quantities. Typical results of the dynamic machine behavior, with adequate interpretation, obtained in recent measurement campaigns of some important hydraulic turbines were presented. The paper highlights the investigation focus of the hydraulic machine behavior and how to tailor the measurement strategy to accomplish all goals. Finally some
Koenigsberger, F
1970-01-01
Machine Tool Structures, Volume 1 deals with fundamental theories and calculation methods for machine tool structures. Experimental investigations into stiffness are discussed, along with the application of the results to the design of machine tool structures. Topics covered range from static and dynamic stiffness to chatter in metal cutting, stability in machine tools, and deformations of machine tool structures. This volume is divided into three sections and opens with a discussion on stiffness specifications and the effect of stiffness on the behavior of the machine under forced vibration c
Smile (System/Machine-Independent Local Environment)
Fletcher, J.G.
1988-04-01
This document defines the characteristics of Smile, a System/machine-independent local environment. This environment consists primarily of a number of primitives (types, macros, procedure calls, and variables) that a program may use; these primitives provide facilities, such as memory allocation, timing, tasking and synchronization beyond those typically provided by a programming language. The intent is that a program will be portable from system to system and from machine to machine if it relies only on the portable aspects of its programming language and on the Smile primitives. For this to be so, Smile itself must be implemented on each system and machine, most likely using non-portable constructions; that is, while the environment provided by Smile is intended to be portable, the implementation of Smile is not necessarily so. In order to make the implementation of Smile as easy as possible and thereby expedite the porting of programs to a new system or a new machine, Smile has been defined to provide a minimal portable environment; that is, simple primitives are defined, out of which more complex facilities may be constructed using portable procedures. The implementation of Smile can be as any of the following: the underlying software environment for the operating system of an otherwise {open_quotes}bare{close_quotes} machine, a {open_quotes}guest{close_quotes} system environment built upon a preexisting operating system, an environment within a {open_quotes}user{close_quotes} process run by an operating system, or a single environment for an entire machine, encompassing both system and {open_quotes}user{close_quotes} processes. In the first three of these cases the tasks provided by Smile are {open_quotes}lightweight processes{close_quotes} multiplexed within preexisting processes or the system, while in the last case they also include the system processes themselves.
DESIGN PROPOSAL OF SCREW PUMP STRUCTURED A SWITCHED RELUCTANCE MOTOR (SP-SRM
Ahmet FENERCİOĞLU
2008-03-01
Full Text Available Structure of a Switched Reluctance Motor (SRM has double salient poles and does not include permanent magnet, conductor and bar. Therefore, this geometrical structure is intended to be used as an advantage for the screw pump proposal; magnetic rotor has been designed partially, inspired from the structure of radial and axial flux SRM. Proposed SRM has 6/4 poles and 3 phase configuration. Screw rotor, which is made of non-magnetic material, has been installed between magnetic rotor and the rotor structure of the screw pump has been obtained. In stator, there are 4 coils of 2000 turns installed in flux path for each phase. The screw rotor isn't included in the magnetic coupling. Here the pump rotor itself is an actuator of direct drive application. This system has been called as SP-SRM. Electrical and magnetic quantities like inductance, torque, power, magnetic flux of the SPSRM have been calculated analytically and predicted by finite elements method (Ansoft Maxwell 3D; it doesn't cover mechanics and dynamics of the proposed system. In the direct drive actuator application where the rotor itself is considered as an actuator, the SP-SRM looks like an attractive choice with its superiority of eliminating the used of a driver motor, couplings and gear boxes.
Impact of Dwell Angle on the Electromagnetic Torque Ripplesof the Switched Reluctance Motor
G. Bhuvaneswari
2008-05-01
Full Text Available Switched reluctance motors (SRM are emerging as promising competitors to the vector-controlled induction motor (VCIM drives and permanent magnet (PM motor drives in the variable-speed drive market owing to their robust nature coupled with low cost, simplicity, and capabilityto operate in harsh environments. They are also suitable for nuclear and aerospace applicationsdue to their low inertia and capability to be fed from a dc supply through a simple power converter.The principle of torque production in SRM makes rotor position information mandatory foreffective control of the drive. The torque produced by any particular phase of the SRM isdependent upon the exciting current and the period during which the current is carried by thatphase winding. The conduction period of any particular phase is termed as dwell angle whenit is specified in terms of rotor angular position. In the present work, the SRM operation has beenanalysed in sensor mode and in sensor-less mode, paying special attention to the relationshipbetween dwell angle and output torque ripple. The performance has been studied for differentvalues of dwell angle and the resultant torque profile has been analysed. From the analysis, amethodology has been devised to deduce an appropriate value of dwell angle for minimising thetorque pulsations, given the values of speed and load torque, thus improving the performanceof the SRM drive.
Analysis and Modeling of Linear-Switched Reluctance for Medical Application
Jean-Francois Llibre
2013-04-01
Full Text Available This paper focuses on the analysis, the modeling and the control of a linear-switched reluctance motor. The application under consideration is medical, and the actuator is to be used as a left ventricular assist device. The actuator has a cylindrical or tubular shape, with a mechanical unidirectional valve placed inside the mover, which provides a pulsatile flow of blood. The analytical expression of the effort based on the linear behavior of the actuator is given. The identification of the characteristics of the prototype actuator and the principle of position control is performed. A modeling of the actuator is proposed, taking into account the variation of inductance with respect to the position. The closed-loop position control of the actuator is performed by simulation. A controller with integral action and anticipatory action is implemented in order to compensate the effects of disturbing efforts and tracking deviations. Moreover, a magic switch is performed in the controller to avoid overshoots. The results show that the closed-loop response of the actuator is satisfactory.
Design and Analysis of an Axially Laminated Reluctance Motor for Variable-Speed Applications
BESER, E. K.
2013-02-01
Full Text Available In this paper, an axially laminated reluctance motor is presented. First, a set of a finite element analysis (FEA on three different axially laminated rotor geometries was carried out and torque profiles of the rotors were predicted. The effect of the stator slot skewing on the torque profiles were also examined in the analysis. After deciding the rotor geometry, the mathematical model of the proposed motor was formed in terms of a,b,c variables and simulations were performed. Motor prototype and motor drive were introduced. Torque profiles of the motor were measured for different current values and load test were realized. Experimental results were compared to analysis and simulation results. There is a good accordance between experimental and simulation results. When the proposed motor is operated with electrical 120? mode as a brushless DC motor, the torque versus speed characteristic shows a DC series motor characteristic and speed of the motor can be easily controlled by regulating the bus voltage. These features make the proposed motor convenient for variable-speed applications such as electrical vehicles.
From Persuasion to Coercion: Responding to the Reluctant Patient in Rehabilitation.
Anderson, Lynley; Delany, Clare
2016-08-01
Early mobilization of patients while in hospital has been demonstrated to provide better outcomes for patients and use fewer resources. Physical therapy-based rehabilitation is central to achieving those goals. Successful rehabilitation requires that patient's and therapist's goals align, and this is commonly the case. However, occasionally, physical therapists will come across patients who are competent but reluctant to mobilize. This situation leaves the physical therapist in an ethical quandary: either accept the patient's right to refuse proposed treatment or utilize other strategies to encourage the patient to adhere to treatment. Practically, physical therapists will use a range of treatment pressures, including persuasion, offering incentives, inducements, possibly threatening or coercing, and even explicitly overriding the patient's wishes (compulsion). Deciding which treatment pressure is ethically acceptable involves the physical therapist balancing his or her therapeutic view of what is in a patient's best interests against the therapist's ethical responsibility to respect patient autonomy. This article evaluates some common strategies used by physical therapists to influence, persuade, or perhaps pressure patients to adhere to rehabilitation. The work of Szmukler and Appelbaum is utilized in analyzing treatment pressures. The authors conclude that there is a spectrum of treatment pressures, with some (persuasion and incentives) being more acceptable than others (threats and compulsion). As physical therapists balance health system pressures for rapid turnover of beds with obligations to benefit patients within limited reimbursement models, while respecting the patients' autonomy, they must be mindful of the effects of treatment pressure on patient care. © 2016 American Physical Therapy Association.
Modeling, Simulation, and Experiment of Switched Reluctance Ocean Current Generator System
Hao Chen
2013-01-01
Full Text Available This paper presents nonlinear simulation model of switched reluctance (SR ocean current generator system on MATLAB/SIMULINK with describing the structure of generator system. The developed model is made up of main model, rotor position calculation module, controller module, gate module, power converter module, phase windings module, flux-linkage module, torque module, and power calculation module. The magnetization curves obtained by two-dimensional finite-element electromagnetic field calculation and the conjugated magnetic energy graphics obtained from the three-dimensional graphics of flux linkage are stored in the “Lookup Table” modules on MATLAB/SIMULINK. The hardware of the developed three-phase 12/8 structure SR ocean current generator system prototype with the experimental platform is presented. The simulation of the prototype is performed by the developed models, and the experiments have been carried out under the same condition with different output power, turn-off angle, and rotor speed. The simulated phase current waveforms agree well with the tested phase current waveforms experimentally. The simulated output voltage curves agree well with the tested output voltage curves experimentally. It is shown that the developed nonlinear simulation model of the three-phase 12/8 structure SR ocean current generator system is valid.
Impact Analysis of Dwell Angles on Current Shape and Torque in Switched Reluctance Motors
Syeda Fatima Ghousia
2012-03-01
Full Text Available The reduction of torque ripple is the main target in research for designing a variable drive system with switched reluctance motors (SRM for higher torque density and better efficiency. This ripple is due to the transition of excitation current between the adjacent phases. Precise control of turn-on and turn off angle is required to smooth the torque. In this paper, the effects of selecting the turn-on and turn-off angles are simulated in detail. It is observed that with the extended turn-on and turn off angles, the precise selection of turn-on and turn off angle can alter the shape of the excitation current in the stator coil and its point of overlapping with the adjacent coil. Therefore the transition between different phases can be smoothed out. The impact of this alteration on the excitation current and torque ripple as a function of different parameters of dwell angle is studied in detail in this paper. It is found that a sinusoidal current shape can also be obtained with the proper selection of these parameters.
Ali UYSAL; Raif BAYIR
2013-01-01
The faults in switched reluctance motors (SRMs) were detected and diagnosed in real time with the Kohonen neural network. When a fault happens, both financial losses and undesired situations may occur. For these reasons, it is important to detect the incipient faults of SRMs and to diagnose which faults have occurred. In this study, a test rig was realized to determine the healthy and faulty conditions of SRMs. A data set for the Kohonen neural network was created with implemented measurements. A graphical user interface (GUI) was created in Matlab to test the performance of the Kohonen artificial neural network in real time. The data of the SRM was transferred to this software with a data acquisition card. The condition of the motor was monitored by marking the data measured in real time on the weight position graph of the Kohonen neural network. This test rig is capable of real-time monitoring of the condition of SRMs, which are used with intermittent or continuous operation, and is capable of de-tecting and diagnosing the faults that may occur in the motor. The Kohonen neural network used for detection and diagnosis of faults of the SRM in real time with Matlab GUI was embedded in an STM32 processor. A prototype with the STM32 processor was developed to detect and diagnose the faults of SRMs independent of computers.