低速大转矩永磁直驱电机极槽选择问题的研究

发布时间：2018-02-21 18:08

本文关键词： 低速大转矩永磁直驱电机极槽配合集中绕组分布绕组谐波抑制　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：低速大转矩永磁直驱电机的应用省去了传统驱动形式中的减速机,其高性能、高效率与易于维护的优点使其受到了越来越多的关注,其作为出力型电机,要保证输出转矩平滑,节省能源,制造工序简单合理。低速大转矩永磁直驱电机的极数很多,输入电源的频率较低,其极槽配合方案有多种组合可选。极数与槽数的选择决定了电机的磁路结构与绕组排列,是电机设计的关键问题之一。本文从降低低速大转矩永磁直驱电机的转矩波动与铁芯损耗两方面考虑,以分数槽绕组的极槽配合为研究对象,展开了研究。低速大转矩永磁直驱电机极数与槽数的比值较大,极数与槽数间的最大公约数与最小公倍数不再能准确对应其齿槽转矩的峰值。基于齿槽转矩公式,研究了齿槽转矩周期数与极数、槽数间的关系,利用极数与槽数间最小公倍数与最大公约数的比值来表示极槽配合对低速大转矩永磁直驱电机齿槽转矩的抑制效果。根据对低速大转矩永磁直驱电机转矩波动抑制与降低铁芯损耗的分析,选择的极槽配合方案要对电机的气隙磁密与绕组中感应电势的谐波分量有很好的抑制效果,并不会对两者的基波造成过大损害。本文根据交流电机绕组理论与单元电机分析法,总结了低速大转矩永磁直驱电机单元极槽配合的约束条件,在此基础上研究了定子槽口与转子磁极间相对位置不同导致气隙磁密中不同谐波分量的大小不同。基于傅立叶谐波分析法,将气隙磁密分解为永磁体励磁分量与槽口引起的畸变分量,计算出能够使气隙磁密中低次谐波得到最大程度削弱的极槽相对位置。本文推导了分数槽绕组单元电机感应电势的谐波绕组系数计算公式,并以此为依据确定不同极槽配合方案对感应电势中低次谐波的抑制能力与对基波的损害程度。本文选择了六种不同的分数槽绕组极槽配合方案,其中三种为集中绕组,三种为分布绕组,通过在有限元软件中建模仿真,对比六种模型中磁密与感应电势的谐波情况,验证了极槽配合削弱气隙磁密与感应电势中谐波的原理。在此基础上,考虑了低速大转矩永磁直驱电机的制造工艺,说明了集中绕组的极槽配合适用于转速低于100r/min的电机,而分布绕组的极槽配合适用于转速高于100r/min的电机。
[Abstract]:The application of low-speed and high-torque permanent magnet direct drive motor saves the reducer in the traditional drive form. Its advantages of high performance, high efficiency and easy maintenance make it receive more and more attention. As a force type motor, the output torque should be smooth. Saving energy, manufacturing process is simple and reasonable. Low speed and large torque permanent magnet direct drive motor has many poles, and the frequency of input power is low. The pole-slot matching scheme has a variety of combinations. The selection of pole number and slot number determines the magnetic circuit structure and winding arrangement of the motor. It is one of the key problems in motor design. In this paper, two aspects of reducing torque ripple and core loss of low-speed and high-torque permanent magnet direct drive motor are considered, and the polar slot coordination of fractional slot winding is taken as the research object. The research is carried out. The ratio of pole number to slot number of low speed and large torque permanent magnet direct drive motor is large, and the maximum common divisor and minimum common multiple between pole number and slot number can no longer accurately correspond to the peak value of tooth slot torque. The relationship between the number of slot torque periods and the number of poles and slots is studied. The ratio of minimum common multiple to maximum common divisor between pole number and slot number is used to express the effect of polar slot fit on the slot torque of low speed and large torque permanent magnet direct drive motor. According to the torque ripple suppression of low speed and large torque permanent magnet direct drive motor. Analysis of making and reducing loss of Iron Core, The pole-slot matching scheme should have a good restraining effect on the air gap magnetic density of the motor and the harmonic component of the inductive potential in the windings, and will not cause too much damage to the fundamental waves of the two. This paper, based on the theory of AC motor windings and the method of unit motor analysis, In this paper, the constraint conditions of pole slot matching for low speed and large torque permanent magnet direct drive motor are summarized. On this basis, the different harmonic components in air gap magnetic density caused by different relative positions between stator slot and rotor magnetic pole are studied. The air gap magnetic density is decomposed into the permanent magnet excitation component and the distortion component caused by the notch, The relative position of pole slot which can make the low and low order harmonics of air gap magnetic density get the maximum weakening is calculated. In this paper, the formula for calculating harmonic winding coefficient of fractional slot winding unit motor is derived. On the basis of this, the paper determines the ability of different polar slot matching schemes to suppress the low order harmonics of induction electromotive potential and the degree of damage to the fundamental wave. In this paper, six different polar slot matching schemes of fractional slot winding are selected, three of which are concentrated windings. The three kinds of windings are distributed windings. By modeling and simulating in finite element software, the harmonics of magnetic density and inductive potential in six models are compared, and the principle of weakening air gap magnetic density and harmonic in inductive electromotive force by pole slot coordination is verified. The manufacturing process of low-speed and high-torque permanent magnet direct drive motor is considered. It is shown that the pole slot fit of the concentrated winding is suitable for the motor with speed less than 100 r / min, while the pole slot matching of the distributed winding is suitable for the motor with speed higher than 100 r / min.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM351

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