Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Performance Analysis of Doubly Excited Brushless Generator with Outer Rotor for Wind Power Application  [cached]
Yingchao Zhang
TELKOMNIKA : Indonesian Journal of Electrical Engineering , 2012, DOI: 10.11591/telkomnika.v10i3.606
Abstract: In this paper, a novel doubly excited brushless generator (DEBG) with outer radial laminated magnetic barrier rotor (RLMB-rotor) for wind power application was designed and analyzed. The DEBG has 10 rotor pole numbers with outer rotor. Its performance is investigated using the 2D transient finite element method. The magnetic fields, torque capability, end winding voltage characteristics, radial magnetic force and energy efficiency were analyzed. All studies in this paper show that the simplicity, reliability, high efficiency and low vibration and noise of the DEBG with outer rotor are attractive for variable speed constant frequency (VSCF) wind power generation system.
应用于微电网的绕线转子无刷双馈电机控制策略研究 Research on control strategy of wound rotor brushless doubly-fed machine applying to microgrid power system  [PDF]
- , 2018,
Abstract: 对应用于微电网发电系统的绕线转子无刷双馈电机控制策略进行了研究.根据微电网的能量管理需求和柴油机的特性,决定发电机组的转速,以期对发电机进行功率控制,实现微电网的频率和电压的稳定.提出标量控制策略并进行仿真;进一步提出功率控制策略,并进行实验,仿真和实验结果表明该种电机能很好地支撑微电网发电,且稳定性好,并网谐波量小
Performance Description of Brushless Doubly-Fed Induction Machine in Its Asynchronous and Variable Speed Synchronous Modes  [PDF]
Hamed Gorginpour, Hashem Oraee, Richard A. McMahon
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2011, DOI: 10.4236/jemaa.2011.312077
Abstract: Brushless Doubly-Fed Machine has attracted considerable attention in recent years due to its advantages. It has the robustness of the squirrel cage induction machine, and the speed and power factor controllability of the synchronous machine as well as the absence of brushes and slip rings, and using a fractionally rated frequency converter. Hence, there are considerable benefits over the conventional machines, when the machine is applied to applications such as a wind turbine generator or high power adjustable speed drive. However, these benefits are obtained in slightly more complex structure, higher cost and larger dimensions in comparison to the conventional induction machine. This paper presents fundamental aspects of the three modes of operation of brushless doubly fed machine, i.e. simple induction mode, cascade induction mode, and synchronous mode. The investigation is performed by analyzing the spatial harmonic contents of the rotor magnetic flux density. The direct cross couplings between stator and rotor fields as well as, indirect cross coupling between stator fields by the special rotor of this machine is described. Furthermore, loss analysis of the machine in various modes is presented and the torque-speed curves for asynchronous modes are obtained. A 2-D magnetodynamic finite element model based on the D-180 4/8 pole prototype machine is extracted and simulated to verify the results.
A Comparative Study of Control Strategies for Performance Optimisation of Brushless Doubly- Fed Reluctance Machines  [PDF]
Milutin G. Jovanovi?
Journal of Electrical Systems , 2006,
Abstract: 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.
Model reduction for brushless doubly-fed wind generators

WANG Pei,LIU Yong-qiang,

控制理论与应用 , 2008,
Abstract: Since the magnetic fields caused by currents of the three windings (power winding, control winding and rotor winding) of brushless doubly-fed wind generator (BDFWG) interact one another in electric machine space, and the complex coupling relation among the windings exists, consequently, BDFWG model has the nature of high dimensions. It is important to reduce the order by making use of the characteristic of multi-time scale of BDFWG, either for operation analysis or for power regulation of BDFWG. In this paper, the nature of multi-time scale of BDFWG is discussed and the relevant singular perturbed model with three-time scale is built. The model of BDFWG derived in the paper lays the theoretical foundation for order reduction of BDFWG.
PID neural network control of brushless doubly-fed machine

GUO Hong-xi,YANG Jin-ming,LIU Wen-gang,

控制理论与应用 , 2008,
Abstract: Brushless doubly-fed machine (BFDM) possesses the common advantages of squirrel-cage induction machine, wire wound induction machine and electromagenetic synchoronous machine. Therefore, it has a good prospect for application in AC drive and wind generating. Because of the complicated spatial coupling characteristics of BFDM between the two windings, the control methods based on the model of BFDM are very complicated. A PID neural network controller (PIDNN) is designed and applied to the speed regulation of BFDM. The exact speed-tracking is then realized by PIDNN controller after training. The dynamics is satisfactory. Finally, the simulaiton result validates the feasibility and effectiveness of this method.
Application of matrix converter to brushless doubly-fed wind generator system

YANG Jun-hu,ZOU Bing,WANG Xiao-hong,WANG Hai-bing,

控制理论与应用 , 2008,
Abstract: Power converter used in doubly-fed wind generator system must possess the capability of bi-directional power flow. Both AC/DC/AC converter and AC/AC Matrix converter(MC) possess this capability, but MC can provide sinusoidal input current and output voltage simultaneously, and the phase of input current can be adjusted to lead, to lag or to coincide with the phase of the input voltage. The magnitude and frequency of the output voltage and the input power factor can be independently adjusted in MC. MC is used to control the voltage magnitude and frequency in the control winding of brushless doubly-fed machine(BDFM), in order to supply excitation for wind generator system. The model reference fuzzy adaptive control strategy is used to control the ratio of voltage versus frequency to regulate the machine rotor speed and power factor. Digital signal processor(DSP) and complex programable logic device(CPLD) are used to construct a MC experiment excitation system based on four-step commutation strategy. The validity, feasibility and stability of the system design are proved by simulation and experimental research. MC is advantageous to practical applications in the future.
Simulation of Outer Rotor Permanent Magnet Brushless DC Motor Using Finite Element Method for Torque Improvement  [PDF]
Uma Devi Kumaravelu,Sanavullah Mohamed Yakub
Modelling and Simulation in Engineering , 2012, DOI: 10.1155/2012/961212
Abstract: A method of simulation and modeling outer rotor permanent magnet brushless DC (ORPMBLDC) motor under dynamic conditions using finite element method by FEMM 4.2 software package is presented. In the proposed simulation, the torque developed at various positions of the rotor, under a complete cycle of excitation of the stator, is analysed. A novel method of sinusoidal excitation is proposed to enhance the overall torque development of ORPMBLDC motor. 1. Introduction The impressive improvement in power electronic switching devices, integrated circuits, developments and refinements in permanent-magnetic materials, and manufacturing technology have led to the development of brushless permanent- magnet motors that offer significant improvements in power density, efficiency, and noise reduction [1]. Brushless permanent-magnet motors are especially demanded in clean and explosive environments such as aeronautics, robotics, food and chemical industries, electric vehicles, medical instruments, and computer peripherals [2–4]. PM D.C. brushless motors use direct feedback of the rotor angular position so that the input armature current can be switched, among the motor phases, in exact synchronism with the rotor motion. This concept is known as self-controlled synchronization or electronic commutation. The electronic inverter and position sensors are equivalent to the mechanical commutator in D.C. motors [4]. There are several reasons for the overwhelming prevalence of motors having inner rotors [3]. These reasons include the ease of heat removal, because the windings are on the outside, and the containment of the rotating element. In some applications, these attributes are not as important as the benefits gained from having an outer rotor and inner stator. Motors having this construction are sometimes called inside-out motors. Outer rotor motors appear most commonly as spindle motors for hard disk drives and as the drive motor for ventilation fans, water pumps, power-assisted steering such as those used to cool CPUs and computer cases. In these applications, the motor becomes an integrated part of a larger structure. Although individual magnets can be used in outer rotor motors, it is common to use a single-bonded magnet ring inside a rotor. Since the stator teeth point outward, this motor is relatively easy to wind. For a given outer radius, an outer rotor motor has a much larger air gap radius than that of an inner rotor motor. As a result, higher torque is achievable, provided the ohmic losses of the stator windings can be dissipated [5–7]. The finite element
Research on an Axial Magnetic-Field-Modulated Brushless Double Rotor Machine  [PDF]
Ping Zheng,Zhiyi Song,Jingang Bai,Chengde Tong,Bin Yu
Energies , 2013, DOI: 10.3390/en6094799
Abstract: Double rotor machine, an electronic continuously variable transmission, has great potential in application of hybrid electric vehicles (HEVs), wind power and marine propulsion. In this paper, an axial magnetic-field-modulated brushless double rotor machine (MFM-BDRM), which can realize the speed decoupling between the shaft of the modulating ring rotor and that of the permanent magnet rotor is proposed. Without brushes and slip rings, the axial MFM-BDRM offers significant advantages such as excellent reliability and high efficiency. Since the number of pole pairs of the stator is not equal to that of the permanent magnet rotor, which differs from the traditional permanent magnet synchronous machine, the operating principle of the MFM-BDRM is deduced. The relations of corresponding speed and toque transmission are analytically discussed. The cogging toque characteristics, especially the order of the cogging torque are mathematically formulated. Matching principle of the number of pole pairs of the stator, that of the permanent magnet rotor and the number of ferromagnetic pole pieces is inferred since it affects MFM-BDRM’s performance greatly, especially in the respect of the cogging torque and electromagnetic torque ripple. The above analyses are assessed with the three-dimensional (3D) finite-element method (FEM).
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.
Page 1 /100
Display every page Item

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