共查询到20条相似文献,搜索用时 15 毫秒
1.
针对小型永磁同步发电机输出电压随风速变化而同趋势变化,无法自我调节等不足.提出了一种全新的集电力电子技术、控制技术及鼠笼异步发电机于一体的动态励磁方法,即经济可靠的笼型异步发电机结合应用SVG(静止无功发生器)技术的方法。结合物理实验与算例,对笼型异步发电机在离网运行时的励磁特点进行了分析,并通过与永磁同步发电机在有效风速工作范围和整体效率等方面的对比.得出了在小型离网风力发电系统中应用笼型异步发电机,相对永磁同步发电机有诸多优点,有着很好的应用前景。 相似文献
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The purpose of this paper is to analyze influence of design data on a component (1 - 2s)~ in stator currents of induction motors, mainly used for cage fault diagnosis. This paper shows that such an approach does not always lead to a correct outcome. The considerations are based on a "classical" model of induction motors extended to cage asymmetry by introducing cage asymmetry factors ko~ and ka. It has been found that in order to estimate the level of the component (1 - 2s)7~, it is enough to know the pole-pair number "p" and the number of rotor slots "N". The main objective of the paper is to provide engineers with simple qualitative prediction of effects due to cage faults for various motors when information on design data is very limited. 相似文献
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《Energy Conversion, IEEE Transaction on》2009,24(1):68-76
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Abstract Improving cooling performance is a key factor when developing induction motors in smaller sizes with larger capacities and higher rotational speeds. Doing so, however, requires thermal analysis to discover the major parameters in the cooling design. This study investigates temperature distributions and heat transfer rates in a small, totally enclosed, fan-cooled induction motor with both numerical and experimental methods. Parametric studies show that (1) the frame is of the utmost importance in the design and (2) that cooling the motor close to stator coils is the most effective method for cooling. Quantitative analyses show the relationship between the size of the motor and the rise in coil temperature. The results from transient and steady-state experiments using a real motor show that (1) the hottest spot is in the rotor surface, and (2) the load-side surface has a higher temperature than that of the fan-side. The hottest spot in the stator coils is the outer surface of the load-side endwinding. The coil temperature is also significantly affected by the attached components of the frame, as well as the contact state between the stator iron and the frame. It is recommended that the current outer fan be redesigned to improve cooling performance. 相似文献
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Ertan H.B. Leblebicioglu K. Avenoglu B. Pirgaip M. 《Energy Conversion, IEEE Transaction on》2007,22(3):566-575
In this paper, a new approach for the calculation of high-frequency losses in induction motors is presented. The input to the motors is assumed to be supplied from a sinusoidal voltage source. The method is based on the two-dimensional (2-D) field solutions of the magnetic circuit, obtained by using a nonlinear ldquoharmonicrdquo solution. Hence, the solution time is very short. From the ldquoharmonicrdquo solution, the air-gap field distribution as well as the fundamental frequency eddy current losses are determined. The high-frequency loss calculation is based on the assumption of a path for eddy currents within a lamination. A constant k is introduced that defines the width of the current flow path. The empirically found k value is verified by a theoretical calculation. The new method is applied to the calculation of losses of two smooth rotor induction motors. The prediction accuracy is found to be very good. The method is also applied to two open rotor slot motors to observe the change in the prediction accuracy. It is found that due to the small slot openings accurate predictions are still possible. The approach presented in this paper requires little time for loss calculation, and is very suitable for minimizing losses at the design stage. 相似文献
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Performance of a Doubly-Fed Induction Motor with Controlled Rotor Voltage Magnitude and Phase Angle 总被引:1,自引:0,他引:1
The performace of a doubly-fed induction motor (DFM) controlled by a voltage phasor at the rotor side is investigated. This voltage has two control parameters: the magnitude and the phase angle. By controlling each one of these two parameters, it is possible to produce the appropriate voltage phasor which must be applied to the induction motor slip rings for achieving certain operation, i.e. any function of load power versus speed. The electromagnetic characteristics in the steady state are determined when the voltage magnitude and its phase angle varies from zero to their upper limits. These limits are dictated by improving performance considerations. 相似文献
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《Energy Conversion, IEEE Transaction on》2005,20(3):620-628
With the ever-increasing pressure on electric motor manufacturers to develop smaller and more efficient electric motors, there is a need for more thermal analysis in parallel with the traditional electromagnetic design. Attention to the thermal design can be rewarded by major improvements in the overall performance. Technical papers published to date highlight a number of thermal design issues that are difficult to analyze. This paper reviews some of these issues and gives advice on how to deal with them when developing algorithms for inclusion in design software. 相似文献
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《Energy Conversion, IEEE Transaction on》2008,23(4):1005-1014
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《Energy Conversion, IEEE Transaction on》2008,23(3):774-780
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A rotary-linear induction motor whose stator possesses two windings generating the rotating and travelling fields is described. A theoretical analysis of the magnetic field and motor performance takes into account finite stator length effects. Computational results are partially verified by experimental measurements of the motor's model. 相似文献
13.
《Energy Conversion, IEEE Transaction on》1987,(1):139-151
This paper presents measured R, L, C, G parameters of the stator winding of a large A-C motor. The values of these parameters were determined within the frequency range from 100 Hz up to 10 MHz with a high quality impedance analyzer. Twenty different measurements of the R, L, C, G parameters of turns, coils and phases are reported. The results should be of help to utility engineers concerned with turn insulation breakdown and surge protection of large A-C motors. The presented data can be used as an aid in development and calibration of wave propagation models needed for computation of electromagnetic transients in the windings of rotating machines. Ontario Hydro's assistance in this work and EPRI's funding are gratefully acknowledged. 相似文献
14.
为准确测量折返式鼠笼弹性支承的刚度,在对其进行数值分析的基础上,设计了自动控制刚度试验系统,根据试验数据分析不同的位移传感器、不同的施力位置、测点位置和力施加速度对支承刚度试验值的影响。研究表明:数值仿真得到的鼠笼弹性支承变形规律与试验测试结果一致,折返套尾端位移比折返处大,且位移与施加的力呈线性关系;不同直径的电涡流传感器测得的刚度与电子千分表相比,最大偏差为10.17%;折返处的刚度测量值稳定性好,力施加位置改变时刚度测量值的最大变化幅度仅为2%,而折返套尾部刚度的最大变化幅度达到20.6%;力施加速度小于60 N/s时其对刚度试验值影响很小。 相似文献
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An analysis of the hysterezis motor with anisotropic rotor has been carried out. Using an elliptical approximation for the hysteresis loop, the expression of the magnetic vector potential in the anisotropic region of the rotor has been obtained both in the case of a stator surface carrying a curent sheet with sinusoidal variation, and in the case of a rotor surface at which the normal component of the flux density has a sinusoidal variation. The relationships established allow to study the dependence of the electromagnetic torque upon the thickness of the anisotropic region made of hysteresis material, the characteristics of the hysteresis material and the degree of anisotropy. The rotor parameters have been studied and an equivalent circuit has been derived in the case of a three-phase motor. 相似文献
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The paper studies the parameters and performance of a motor with a multistacked imbricated permanent magnet rotor. An experimental motor with ferrites for excitation is used in the investigation. Methods used in the determination of the parameters, Xd, Xq and the core-loss component, Rc, are described. Their variation with load and terminal voltage are also discussed. These parameters are applied in a model based on the classical two-axis machine theory for performance analysis. Detailed investigation shows that the reactance characteristics under steady-state conditions are similar to a wound rotor machine. Computed results using these values of Xd, Xq and Rc show agreement with experimental results. The significance of Rc is noted. 相似文献
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