共查询到18条相似文献，搜索用时 203 毫秒
1.
With the air gap magnetic field distribution of surface mounted permanent magnet (PM) motors obtained using an analytical technique, the instantaneous electromagnetic torque and its corresponding components are investigated with the Maxwell stress tensor method. Accurate results can easily be achieved using the proposed method without using the tedious finite element analysis (FEA). In this paper, the electromagnetic torque of a surface mounted PM motor with two phases energized is decomposed into four torque components. This technique is useful not only for the design and optimization of the permanent magnet motor, but also for the choice of control strategy. 相似文献
2.
A novel elevator door driven by tubular permanent magnet linear synchronous motor （TPMLSM） is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet （PM）, on magnetic field was studied and the best values were given by the finite element analysis （FEA）. The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying. 相似文献
3.
In order to deal with torque pulsation problem caused by traditional control method for brushless DC （BLDC） motor and to achieve high precision and good stability, a novel control strategy is proposed. Compared with the traditional control scheme, by using phase voltage as a control objective and making waveform of phase current approximately quasi-sinusoidal, torque ripple of BLDC motor is reduced from the original 14% to 3.4%, while toque is increased by 3.8%. Furthermore, by detecting zero-crossings of back electromotive force （BEMF） with non-conducting phases, sensorless control is realized. The new control strategy is simple. It can minimize torque ripple, increase torque, and realize sensorless control for BLDC motor. Simulation and experiments show good performance of BLDC motor by using the new control method. 相似文献
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5.
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 waveform 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 61.1% 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. 相似文献
6.
An approach of position sensorless control for permanent magnet synchronous motor （ PMSM ） is put forward based on a sliding mode observer. The mathematical model of PMSM in a stationary αβ reference frame is adopted, and the system is controlled by the digital signal processor （ DSP; TMS320LF2407 according to the control achieve closed loop operation of the motor, the stator theory of sliding mode observer. In order to magnetic field should be vertical with the rotor magnetic field and be synchronous with rotor rotating, so the position and speed of PMSM is estimated in real time and the estimated position is modified continuously. The simulation results indicate that the proposed observer has high precision is more robust to the parametric variation and load in estimation of PMSM position and speed, and torque disturbance. 相似文献
7.
永磁直线同步电机磁阻力优化的设计 总被引：1，自引：0，他引：1
The detent force of a permanent magnet linear synchronous motor （PMLSM） is analyzed and the corresponding optimization methods are presented to reduce it. The detent force, which is divided into two components, i.e. resulting from the end effect and resulting from the slotting effect, can be analyzed respectively by the finite element method （FEM）. To reduce the detent force arising from the end effect, several optimal design techniques are utilized, namely, adopting the suitable length and end shape of the primary armature. The detent force resulting from the slotting effect is reduced by means of skewing and adjusting the width of the magnets mounted on the secondary armature, and adopting the fractional slots of the primary armature. The validity of the analytical detent force predictions and the effectiveness of the detent force reduction techniques are verified by the experimental measurements. 相似文献
8.
This paper presents an investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor （PMSM） direct torque control （DTC） system under various inverter faults. The performance of a faulty standard 6-switch inverter driven PMSM DTC system is analyzed. To avoid the loss or even disaster caused by the inverter faults, a topology-modified inverter with fault-tolerant capability is introduced, which is reconfigured as a 3-phase 4-switch inverter. The modeling of the 4-switch inverter is then analyzed and a novel DTC strategy with a unique nonlinear perpendicular flux observer and feedback compensation scheme is proposed for obtaining a continuous, disturbance-flee drive system. The simulation and experimental results demonstrate that the proposed inverter fault-tolerant PMSM DTC system is able to operate stably and continuously with acceptable static and pretty good dynamic performance. 相似文献
9.
On the basis of the current sheet model, a new analytical solution for permanent magnet （PM） bearings is developed. Compared with analytical methods based on the coupling energy model and the magnetic dipole model, the proposed one is more physically intuitive and convenient for engineering designers. According to the analytical model, the thrust characteristics of a novel PM thrust bearing is studied and verified by finite element analysis （FEA）. In the proposed thrust bearing configuration, the rotor is composed of stacked PM tings with alternative axial magnetization directions, and the stator with alternative radial magnetization directions while copper rings are used to separate adjacent PM rings. A prototype PM thrust bearing with the proposed configuration is designed and fabricated. The performances of the PM thrust beating are experimentally validated. It is shown that the calculation accuracy of the presented analytical solution is satisfying. 相似文献
10.
We proposed the flat-type permanent magnet linear alternator （LA） for free piston linear alternators （FPLAs） instead of the tubular one. Using the finite element method （FEM）, we compare these two kinds of LAs. The FEM result shows that the flat-type permanent magnet LA has higher efficiency and larger output specific power than the tubular one, therefore more suitable for FPLAs, and that the alternator design can be optimized with respect to the permanent magnet length as well as the air gap. 相似文献
11.
In this paper, a design method for ocean wave permanent magnet synchronous generator(PMSG)is proposed with new performance criteria to obtain better output performance at the cost of less permanent magnet material. Besides, a simple equivalent analytical geometry method is put forward to calculate the sizes of permanent magnets. Based on geometric and electromagnetic models, four types of rotor structures are compared, i.e., embedded, tangential, tile surface mount and convex surface mount structures. The designs and comparisons of machine are performed with the same permanent magnet volume. Moreover, the influences of mechanical pole-arc coefficient of tile surface mount PMSG on electrical efficiency, output power, material corrosion, core loss, and torque ripple are investigated. Finite-element analysis method is applied to verify the results using Ansoft/Maxwell. 相似文献
12.
3D Magnetic Field Computation of a Permanent MagnetDisc-Type Generator Using Scalar Potential Method
The three-dimensional magnetic field of a permanent magnet (PM) disc-type generator is analyzed by the scalar potential method.
In the analysis the permanent magnets are taken as magnetic charges. Hexahedron element meshes are automatically generated
by a pre-processing program developed by the authors. The flux density is computed by a 3D scalar potential method program.
Based on the finite element analysis the induced emf, current, armature reaction effects and electromagnetic torque of the
disc machine are all calculated. 相似文献
13.
利用JMAG-Studio软件建立永磁电机的场路耦合的有限元模型,计算并分析永磁电机的空载和负载时瞬态特性,直观地展示电机的电流、反电动势、磁通密度、转矩等性能,并制作成基于电机转子旋转的动画,帮助学生深入理解电机的基本概念和知识,提高电气自动化类专业的电机类课程的教学效果。 相似文献
14.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｉｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｔｏｒｑｕｅｄｅｖｅｌｏｐｅｄｂｙａｐｅｒｍａｎｅｎｔｍａｇｎｅｔｂｒｕｓｈｌｅｓｓｄｃｍｏｔｏｒｉｓｐｒｏｐｏｒｔｉｏｎａｌｔｏｔｈｅｍａｇｎｉｔｕｄｅｏｆｍｏｔｏｒｐｈａｓｅｃｕｒｒｅｎｔｓ.ＴｈｉｓｌｉｎｅａｒｒｅｌａｔｉｏｎｓｈｉｐｍａｋｅｓｉｔｃｏｎｖｅｎｉｅｎｔｔｏｃｏｎｔｒｏｌＢＬＤＣＭｔｏｒｑｕｅｐｒｏｄｕｃｔｉｏｎｂｙｒｅｇｕｌａｔｉｎｇｔｈｅｍｏｔｏｒｐｈａｓｅｃｕｒｒｅｎｔｓ[1].Ｉｎｔｈｉｓｐａｐｅｒ,ｔｈ… 相似文献
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对稀土交流永磁电机的结构特点进行了分析,研究了电机的数学模型.充分利用转子位置检测器的转子检测信号,进行特殊的逻辑处理以完成复杂的矢量控制,使定子电流和感应电势同相,从而达到用电流来控制电磁转矩的目的.文章给出了具体工作电路和特殊问题的处理方法. 相似文献
16.
为了保证电机长期运行可靠性和输出转矩能力,永磁电机温度场的精确计算是其设计与开发的基础,而常规数值离散过程需要进行复杂的数学变换,掌握其核心机理所需的前置课程多、学习难度大。有限公式法离散方程物理意义清晰明确,将之应用于教学可提高学生对数值算法的基本思想及分析方法的理解。通过对基于有限公式法的实际工程案例分析讲解,可培养学生应用数值算法解决复杂工程案例的能力。该文分析和推导了基于有限公式法的永磁电机温度场数学模型,分析其物理意义;搭建了基于有限公式法的永磁电机三维温度场数值计算平台,为永磁电机设计类课程中温升分析与冷却设计提供了有效的教学条件。 相似文献
17.
对用于自动门控制系统的永磁无刷直流电动机,采用基于等效磁路法的RMxprt软件和基于电磁场有限元分析法的Maxwell软件对样机进行设计、分析和计算,并用＂场路结合＂的设计思路,完成了一台12槽/8极无刷直流电机的电磁设计任务。 相似文献