多边形转子磁轭永磁同步电机转子二维电磁力特性研究

发布时间：2018-09-09 08:56

【摘要】：永磁同步电机作为目前应用非常广泛的设备动力源,具有功率密度高、损耗比重小、动态响应快等优点。以永磁同步电机为核心部件的伺服系统,为制造业以及相关产业解决了诸多工艺上的难题。永磁同步电机转子的结构繁多,作为其优化设计的产物,多边形转子磁轭结构在提高电机反电势正弦度,降低转矩波动方面具有相当大的优势,受到了人们越来越多的关注。然而,在现有研究中,对采用这种结构的永磁同步电机的转子受力情况研究还较为欠缺,制约着其性能的进一步提高,因此,本文以多边形转子磁轭永磁同步电机为研究对象,开展了基于磁场分区域解析法的转子二维电磁力特性研究,对该结构在永磁同步电机中进一步的应用和发展都具有相当的意义。本文的研究工作主要分为四个阶段,由于磁场是求解电磁力的基础,所以本文首先采用分区域方法对多边形转子磁轭永磁同步电机的空载气隙磁场进行了解析计算。在求解过程中,将整个电机面域分为了4部分,并利用交界条件将它们联系起来。针对多边形转子磁轭结构的特殊性,在该部分提出了转子磁轭半径函数与偏心永磁体半径函数,用以描述不均匀气隙长度,并根据由交界条件转化而来的矩阵方程,确定了空载气隙磁场的分布情况。将该方法的计算结果与有限元计算结果进行对比,其吻合度较高。其次,采用类似的方式,忽略永磁体的磁化强度,并假设永磁体与气隙的相对磁导率相同,将电机面域分为3部分,对电枢反应气隙磁场进行了解析计算,将其结果与有限元计算结果进行对比,验证了解析过程的正确性,为负载气隙磁场以及负载二维电磁力的分析奠定了基础。再次,基于前两章节的磁场解析结果,根据麦克斯韦应力公式对多边形转子磁轭永磁同步电机的转子二维电磁应力分布进行了求解,将计算结果分解为三部分,对每一部分进行了详细的分析,并与普通圆形转子磁轭永磁同步电机的受力情况进行对比,探究了两者的区别。同时,将二维电磁应力的径向分量与切向分量分别投影到X与Y方向,通过积分得到了整个转子所承受的不平衡磁拉力,研究了不平衡磁拉力的特性及其与电机结构尺寸的内在联系。最后,设计了实验样机结构,并进行了4组实验。通过对样机空载反电势与电感的测试,验证了磁场解析的正确性;通过对样机不平衡磁拉力的测试,验证了二维电磁力求解分析的正确性。
[Abstract]:Permanent magnet synchronous motor (PMSM) as a very widely used power source has the advantages of high power density, low loss, fast dynamic response and so on. The servo system based on permanent magnet synchronous motor (PMSM) has solved many technical problems for manufacturing and related industries. The rotor structure of permanent magnet synchronous motor (PMSM) is various. As the product of its optimal design, the polygonal rotor yoke structure has considerable advantages in increasing the sinusoidal potential of the motor and reducing the torque ripple, which has attracted more and more attention. However, in the existing research, the research on the rotor force of permanent magnet synchronous motor (PMSM) with this structure is still lacking, which restricts the further improvement of its performance. Therefore, this paper takes the polygonal rotor yoke permanent magnet synchronous motor as the research object. In this paper, the two-dimensional electromagnetic force characteristics of the rotor based on the magnetic field analysis method are studied, which is of great significance to the further application and development of the structure in the permanent magnet synchronous motor (PMSM). The research work in this paper is divided into four stages. Because the magnetic field is the basis of solving the electromagnetic force, the no-load air-gap magnetic field of the polygonal rotor yoke permanent magnet synchronous motor is analytically calculated in this paper. In the process of solving, the whole motor area is divided into four parts, and they are connected by using the boundary condition. In view of the particularity of the polygonal rotor yoke structure, the rotor yoke radius function and the eccentric permanent magnet radius function are proposed in this part to describe the nonuniform air gap length, and the matrix equations are derived from the boundary conditions. The distribution of no-load air gap magnetic field is determined. The result of this method is compared with that of finite element method. Secondly, in a similar way, the magnetization of permanent magnet is ignored, and assuming that the relative permeability of permanent magnet and air gap is the same, the plane region of motor is divided into three parts, and the air-gap magnetic field of armature reaction is calculated analytically. The results are compared with the results of finite element analysis, which verify the correctness of the analytical process and lay a foundation for the analysis of the load air-gap magnetic field and the load two-dimensional electromagnetic force. Thirdly, based on the analytical results of magnetic field in the first two chapters, the two-dimensional electromagnetic stress distribution of the permanent magnet synchronous motor with polygonal rotor yoke is solved according to Maxwell's stress formula, and the result is decomposed into three parts. Each part is analyzed in detail and compared with the general circular rotor yoke permanent magnet synchronous motor (PMSM), and the difference between them is explored. At the same time, the radial and tangential components of two-dimensional electromagnetic stress are projected to X and Y directions, respectively, and the unbalanced magnetic tension of the whole rotor is obtained by integral. The characteristics of unbalanced magnetic pull force and its internal relation with the structure size of motor are studied. Finally, the structure of the experimental prototype is designed, and four groups of experiments are carried out. The correctness of the magnetic field analysis is verified by testing the no-load reverse EMF and inductance of the prototype, and the correctness of the two-dimensional electromagnetic force solution analysis is verified by the testing of the unbalanced magnetic pull force of the prototype.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM341

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