oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
FUNDAMENTALS OF THE THEORY OF SYNCHRONOUS MACHINES WITH MULTIPLE WINDINGS OF THE STATOR Основы теории синхронных машин с несколькими обмотками на статоре  [PDF]
Strizhkov I. G.
Polythematic Online Scientific Journal of Kuban State Agrarian University , 2012,
Abstract: The article is an attempt to generalize the theory of the mathematical description of synchronous ma-chines with multiple three-phase windings on the sta-tor and arbitrary location in space of the machine. The features of the transformations of coordinates in the mathematical description of the machine are shown
On the Segmented Rotor Reluctance Synchronous Motor Saliency Ratio Calculation  [cached]
Ioan Adrian Viorel,Attila Banyai,Claudia Steluta Martis,Bogdan Tataranu
Advances in Electrical and Electronic Engineering , 2006,
Abstract: The reluctance synchronous motor performance highly depends on its saliency ratio. Therefore an accurate analytical calculation of the motor’s saliency is quite a necessity within the designing procedure. In this paper an analytical method to calculate the main motor inductances and its saliency ratio is applied to a segmented rotor reluctance synchronous motor. The results obtained for two motor variants, compared with the ones obtained via a 2-D FEM computation and via tests, stand by to prove the proposed technique accuracy.
Artificial Neural Network Based Rotor Position Estimation for Switched Reluctance Motor  [cached]
L.Jessi Sahaya Shanthi,R. Arumugam,Y.K. Taly,S.B. Nandha Kumar
Modern Applied Science , 2009, DOI: 10.5539/mas.v2n6p148
Abstract: Switched Reluctance Motor (SRM) is becoming popular as a variable speed industrial drive. But the requirement of position sensor to synchronize the rotor position with phase currents makes the SRM drive circuit complex and unreliable. With the advent of high speed digital signal processors, it is possible to implement algorithms to estimate the rotor position based on the electrical signals in motor windings. In addition to this, the latest graphical user interface software aids to reduce the time for the development of control algorithms. This paper presents the simulation study of an artificial neural network(ANN) based algorithm for rotor position estimation from phase voltage and current of a four phase SRM using VISSIM version 6.0B software. Based on the simulation results, a particular artificial neural network (ANN) is selected and checked for real time implementation.
12相低速永磁同步电动机电磁设计与分析
Electromagnetic Design and Analysis of Twelve-Phase Low-Speed Permanent Magnet Synchronous Motor
 [PDF]

陈益广,,,,,赵国平,郭喜彬
- , 2016, DOI: 10.11784/tdxbz201509050
Abstract: 多相永磁同步电动机能够在低电压供电场合实现大功率、低噪声和高可靠性驱动.介绍了额定转速 120,r/min 的 3.5,MW 低速永磁同步电动机设计过程,转子为表贴式结构,合理地选择相数和槽极数配合,定子采用 192 槽 40 极 4,Y 相移 15°分数槽双层短距分布绕组,整个定子可以看作由 4 个 48 槽 10 极 4,Y 相移 15°单元电机构 成.所设计的多相永磁同步电机径向力波模数高,引起的电机壳体振动幅度小.分析了单元电机的永磁电动势、电 枢反应磁动势和电磁转矩特点.对电机进行了电磁优化设计,给出了电机主要结构参数.分析结果表明:该电机的 电磁脉动转矩小,能够获得较好的力能指标.
The multi-phase permanent magnet synchronous motor(PMSM) can output greater power under low DC bus voltage with less noise and its drive system has higher reliability.A low-speed permanent magnet synchronous motor with a rated power of 3.5,MW and a rated speed of 120,r/min was designed.More reasonable phase number and slot-pole number were chosen.The rotor is surface-mounted,and the stator is 192-slot/40-pole.The stator has four Y-connected fractional-slot and double-layer short-pitch distribution windings displaced in turn by 15°.The ma- chine entire stator is viewed as being composed of four 48-slot/10-pole unit motors.The radial force of the motor has higher modal order,and therefore,the vibration amplitude of motor shell caused by it is lower.The characteristics of permanent magnet electromotive force,magnetic motive force and electromagnetic torque were investigated.The motor was optimized through changing the structure of the stator and rotor,finally the structure parameters were de- termined.The results proved that the motor has lower electromagnetic ripple torque,and higher power index
Effect of Rotor Eccentricity Faults on Noise Generation in Permanent Magnet Synchronous Motors
Ali Rezig;Mohamed Rachid Mekideche;Abdesselem Djerdir
PIER C , 2010, DOI: 10.2528/PIERC10071001
Abstract: Vibrations and noise in electrical machines are directly related to the characteristics of the radial forces on one hand, and mechanical behavior on the other. The characteristics of these forces depend on the air gap flux density, and they are influenced by other factors such as stator slots and poles, saturation level, winding type and certain faults. The aim of this work is to investigate the effect of eccentricity faults on electromagnetic noise generated by the external surface of PM synchronous machine (PMSM). For this purpose an analytical electromagnetic vibroacoustic model is developed. The results confirm the effect of eccentricity fault in generating some low modes radial forces. An experimental device is installed to validate the results of the analytical model.
Direct-Drive Synchronous Generators with Excitation from Strontium-Ferrite Magnets: Efficiency Improvement
A. Serebryakov, N. Levin, A. Sokolov
Latvian Journal of Physics and Technical Sciences , 2012, DOI: 10.2478/v10047-012-0018-0
Abstract: The authors consider the possibility to raise the specific power of synchronous generators with excitation from inexpensive permanent magnets. For this purpose, it is proposed to use tooth-wise windings and permanent magnets based on inexpensive magneto-hard material, e.g. strontium-ferrite. The magnets are to be placed between the rotor teeth, the alternate polarity of which is facing the air-gap. This provides a simpler and cheaper technology of making such a generator and improves its reliability. The proposed rational bevelling of the stator teeth not only raises the specific power of the generator but also reduces the level of noise and vibrations, extends the longevity of the magnets and bearings as well as facilitates the starting torque of the electric machine, e.g. if it is employed as wind generator.
Harmonic Analysis and Fault-Tolerant Capability of a Semi-12-Phase Permanent-Magnet Synchronous Machine Used for EVs  [PDF]
Ping Zheng,Fan Wu,Yi Sui,Pengfei Wang,Yu Lei,Haipeng Wang
Energies , 2012, DOI: 10.3390/en5093586
Abstract: 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.
Analysis and Experiment of a Novel Brushless Double Rotor Machine for Power-Split Hybrid Electrical Vehicle Applications  [PDF]
Ping Zheng,Qian Wu,Jingang Bai,Chengde Tong,Zhiyi Song
Energies , 2013, DOI: 10.3390/en6073209
Abstract: A novel brushless double rotor machine (BDRM) is proposed in this paper. The BDRM is an important component in the brushless compound-structure permanent-magnet synchronous machine (CS-PMSM) system, which is a promising technology for power-split hybrid electric vehicle (HEV) applications. Compared with common double rotor machines, the brushes and slip rings required by rotating winding have been omitted in the BDRM, thus there are no such problems as maintenance, friction losses and so forth. Firstly, the torque characteristics of the BDRM are analyzed. As the stator has ring-shaped centralized windings, the size characteristics of the BDRM are different from those of conventional machines. The new sizing and torque equations are analyzed and the theoretical results are applied to determine the main dimensions. Additionally, studies of the analytical magnetic circuit and finite element method (FEM) model show that the BDRM tends to have high leakage flux and low power factor. Although the scope for improving the serious flux leakage of the BDRM is limited by the special magnetic topology, a method to obtain higher power factor is provided. Finally, a 10 kW prototype machine was manufactured, assembly of the prototype is discussed in detail and experimental tests are performed to validate the analytical and simulation results.
An Improved Analytical Model for Salient Pole Synchronous Machines Under General Eccentricity Fault
Hamidreza Akbari
PIER B , 2013, DOI: 10.2528/PIERB13010101
Abstract: This paper develops a more precise analytical model for calculating salient pole synchronous machine (SPSM) inductances in case of general eccentricity including static, dynamic and mixed eccentricities. The developed method is based on the modified winding function approach (MWFA) which accurately considers variable air gap function and leads to pure analytical expressions of inductances. Available analytical techniques, based on MWFA, approximate the air gap function and simplify the geometrical model of SPSM, whereas, in this study, the influence of the openings between the rotor salient poles has been taken into account by using an effective form of rotor pole shoes. Using this technique, flux fringing effect is considered. By taking into account machine geometry, type of windings connection and flux fringing effect, this method is able to model most of the important features of an eccentric SPSM. The developed analytical expressions can calculate time varying inductances of SPSMs with any eccentricity type and degree in the frame of a single program. Simulation results for static eccentricity are compared with experimental tests on a laboratory generator to verify accuracy of the proposed model.
Windings of the stable Kolmogorov process  [PDF]
Christophe Profeta,Thomas Simon
Mathematics , 2014,
Abstract: We investigate the windings around the origin of the two-dimensional Markov process (X,L) having the stable L\'evy process L and its primitive X as coordinates, in the non-trivial case when |L| is not a subordinator. First, we show that these windings have an almost sure limit velocity, extending McKean's result [McK63] in the Brownian case. Second, we evaluate precisely the upper tails of the distribution of the half-winding times, connecting the results of our recent papers [CP14, PS14].
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.