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无刷直流电动机电磁转矩无脉动的条件 总被引:2,自引:0,他引:2
从气隙磁场为梯形波的假设出发,研究换向方式、磁场波形及电枢绕组分布对输出电磁转矩的影响,导出开关式无刷电动机输出电磁转矩无脉动的充分条件及整数槽电机、分数槽电机、无齿槽电机分别满足输出电磁转矩无脉动的条件,并用此条件进行了实例计算。 相似文献
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Halbach永磁阵列具有灵活配置电机气隙磁通密度、磁屏蔽的特点,将其用于无刷直流电机以增加电磁转矩、降低齿槽转矩。在保角变换求解电磁场基础上,给出无刷直流电机电磁转矩与齿槽转矩的解析计算模型,通过有限元仿真对该模型的准确性进行证明;使用该模型分析每极两块(1P2p)、每极三块(1P3p)Halbach永磁阵列中主磁钢弧角和辅磁钢充磁方向角对无刷直流电机电磁转矩与齿槽转矩的影响,对比分析径向充磁、平行充磁和Halbach永磁阵列的无刷直流电机电磁转矩与齿槽转矩随永磁体厚度的变化规律。分析结果表明,合理配置无刷直流电机Halbach永磁阵列中主磁钢弧角和辅磁钢充磁方向角可提高电磁转矩、降低齿槽转矩,当永磁体厚度增加时,Halbach永磁阵列更有利于电磁转矩增加。 相似文献
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稀土永磁无刷直流电动机反电势及电磁转矩的计算 总被引:3,自引:0,他引:3
用类似直流电机的分析方法,推导了永磁无刷直流电动机的电势和电磁转矩公式,讨论了这种电机的电枢反应,得出空载磁通与负载磁通近似相等的结论。 相似文献
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双三相永磁同步电机电磁性能解析计算 总被引:1,自引:0,他引:1
采用傅里叶级数法计算表贴式双三相永磁同步电机的电磁性能。解析模型建立在二维极坐标下,求解区域划分为槽、槽开口、气隙和永磁体四类子域。以矢量磁位为求解变量,在槽开口和气隙子域建立拉普拉斯方程,在槽和永磁体子域建立泊松方程,根据分离变量法求解偏微分方程,并利用各子域之间的边界条件得到谐波系数。解析模型考虑了径向/平行/Halbach等多种充磁方式,内/外永磁转子结构,适用于隔齿绕/全齿绕两种形式的分数槽集中绕组,可用于计算电机空载磁场、电枢反应磁场和负载磁场。在解析模型的基础上,求解了齿槽转矩以及两种分数槽集中绕组连接方式下的空载反电动势和电磁转矩。与有限元结果相比较,表明了解析方法的准确性。 相似文献
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对电动汽车轮毂直接驱动用外转子永磁无刷直流电动机的电枢反应作了详细分析。通过对电枢槽电流分布的傅立叶分析和静态磁场分析.证明了电枢反应对气隙磁密和电磁转矩的影响可忽略不计。故为电机电磁设计时,把空载工作点的磁通近似看作负载工作点的磁通的结论提供了数值依据。 相似文献
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永磁无刷直流电机空载气隙磁场和绕组反电势的解析计算 总被引:24,自引:21,他引:24
该文利用许-克变换构造了考虑齿槽效应的气隙相对比磁导函数,该气隙相对比磁导函数反映了齿槽效应对气隙磁场分布的影响,且这种影响的程度随气隙中的径向位置而变化,在忽略铁心饱和的情况下,结合偏微分方程的解析算法,提出了一种考虑齿槽效应的永磁无刷直流电机空载气隙磁场分布和相绕相反电动势的解析计算方法,计算结果与二维有限元计算结果对比,其计算波形和大小吻合很好,证明此方法是正确的、可靠的、为永磁无刷直流电机优化设计和性能分析提供了基本分析手段。 相似文献
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应用于航空航天领域的稀土永磁无刷直流电动机采用多重电枢绕组技术以提高可靠性。采用隔槽嵌放的双绕组电机系统成本高,结构复杂。该文给出双绕组的一种同槽嵌放方式,对双绕组稀土永磁无刷直流电动机在单绕组工作和双绕组工作时,同槽和隔槽嵌放方式的磁势进行了理论分析,结果表明,在磁路饱和的情况下,单绕组工作时同槽嵌放电枢磁势的去磁作用小,而双绕组工作时,隔槽嵌放的电枢磁势去磁作用小;同槽嵌放更适用于冷备份余度模式,隔槽嵌放则宜于热备份余度模式。对电枢磁场、空载磁场、负载磁场和机械特性进行了有限元仿真计算,并对隔槽嵌放样机的机械特性进行了测试,仿真和测试结果验证了理论分析的正确性。 相似文献
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集中绕组永磁无刷直流电机电枢反应及绕组电感的解析计算 总被引:13,自引:5,他引:13
基于深槽集中绕组的结构特点,采用镜像法,建立了适合集中绕组无刷电机的电枢反应求解模型。充分考虑电机齿槽影响,给出了电枢反应磁场的解析表达式,对不同控制方式下的电枢反应分别作了研究,并在此基础上推导了电机绕组电感的通用求解公式,从而为集中绕组无刷电机的参数设计和特性分析提供了理论依据。样机实验表明,其具有很好的工程适用性,理论计算与实测值吻合。 相似文献
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Takano H. Itoh T. Mori K. Sakuta A. Hirasa T. 《Industry Applications, IEEE Transactions on》1992,28(2):350-357
When the motor thickness and the required starting torque are set for an axial-field permanent magnet brushless DC motor, the optimal ratio of the permanent magnet thickness to armature winding thickness is 2:1 because the copper loss of the armature windings is kept to a minimum. This conclusion is based on a new method presented by the authors in which factors such as loop resistance, a radial air gap magnetic flux density approximated by curves of second order, and an experimental formula for the leakage coefficient are incorporated. The demagnetization curves of the magnets are assumed to be linear. The new method is also applicable to estimating torque, current, and input power at the start. These items can be more promptly estimated without a computer program, and the physical insight is more easily gained by the aid of the new method than a 3-D finite element method 相似文献
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Huang Ping-lin Hu Qian-sheng Yu Li Huang Yun-kai 《Frontiers of Electrical and Electronic Engineering in China》2006,1(3):355-360
Based on the configuration of deep slot concentrated coils, an analytical model is developed for predicting the armature reaction
field produced by the 3-phase stator windings of permanent magnet brushless DC motors with concentrated coils by using the
image method and the analytical functions of the armature reaction and winding inductances are proposed accounting for the
influence of stator slotting. This approach is different from the method of equivalent distributed current sheet and more
suitable for electric machines, which have concentrated coils and deeper slots. Under different control mode, the different
analytical functions are presented. This will be helpful when further analyzing the performance of the motor. The results
agree with the experiment very well.
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Translated from Proceedings of the Chinese Society for Electrical Engineering, 2005, 25(12): 127–132 (in Chinese) 相似文献
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Chan C.C. Jiang J.Z. Chen G.H. Wang X.Y. Chau K.T. 《Industry Applications, IEEE Transactions on》1994,30(5):1258-1266
A novel high-power-density permanent magnet (PM) motor drive for electric vehicles (EVs) is proposed. The motor is a polyphase multipole square-wave PM motor, which can be classified as a kind of PM brushless DC motor. The distinct features of the proposed motor as compared to those of the conventional PM brushless DC motor are as follows. First, the multipole magnetic circuit arrangement enables the minimization of the magnetic yoke, resulting in the reduction of motor volume and weight. Second, the coil span is purposely designed to be equal to one slot pitch, thus saving the amount of copper used. Third, by using a fractional number of slots per pole per phase, the arrangement of the numbers of poles and slots is so unique that the magnetic force between the stator and the rotor at any rotating position is uniform, hence eliminating the cogging torque that usually occurs in PM motors. Finally, the motor can be controlled to operate at a constant torque region and a constant power region with field weakening, thus both high starting torque and high cruising speed can be achieved. Therefore, as the proposed motor drive possesses the distinct advantages of high power density, high efficiency, and superior dynamic performance, it is very suitable for EV applications. A prototype of a five-phase 22-pole 5 kW motor drive has been designed for an experimental EV 相似文献