Halbach 阵列同心式磁力齿轮全局解析法分析与优化设计

发布时间：2018-08-27 12:41

【摘要】：Halbach阵列同心式磁力齿轮依靠磁场作用传递转矩，其输入和输出之间非接触性传递使它具有转矩密度高、运行效率高和过载保护等优点。此种磁力齿轮内外转子采用同心式结构，有效地提高了永磁体的利用率，其转矩密度和运行效率较传统结构有较大的提高，因此具有较好的应用前景。本课题是国家自然科学基金项目“磁通解耦型磁力变速永磁无刷电机研究”(51177097)的研究内容之一，，对新型结构的磁力传动装置进行研究。本文采用矢量磁位全局解析法对Halbach阵列同心式磁力齿轮展开研究，具体做了以下几方面的研究：第一，采用二维全局解析法计算同心式磁力齿轮气隙磁场。求解场域划分为内外转子永磁体、内外两层气隙和调磁定子的槽形区域，3类子区域的拉普拉斯方程和泊松方程通过边界连续条件建立联系。得到内外两层气隙区域的矢量磁位磁通密度解析表达式，计算了内、外两层气隙磁场；利用Maxwell应力张量法计算了内外转子电磁转矩；将气隙磁场波形和内外转子电磁转矩波形分别与二维有限元FEMM软件计算波形作比较，两者结果一致性好；在此基础上，分析了两层气隙的谐波磁场和电磁转矩的静态特性。第二，根据Halbach阵列充磁原理，推导出Halbach阵列充磁下的数学模型，也是采用全局解析法计算Halbach阵列同心式磁力齿轮内、外气隙磁场及其转矩，分析对比了两种充磁方式下磁力线的分布，将全局解析法计算结果与有限元软件FEMM计算结果进行了比较；同时也对两种充磁方式下气隙谐波大小和转矩做了比较。两种充磁方式下计算的波形与有限元计算结果的吻合也为磁力齿轮的参数优化设计奠定了基础。第三，从提高磁力齿轮的转矩密度出发，首次将MATLAB优化工具箱中的遗传算法运用到磁力齿轮优化设计中，在优化的过程中，不再进行人工干预，较有限元法优化设计方便、快捷。根据所选模型的优化目标，选取对优化目标影响较大的参数作为优化变量，选择合适的算子及概率，同时根据各参数和静态转矩之间的关系确定各参数的取值范围；用全局解析法计算优化后磁力齿轮电磁转矩，并且与磁力齿轮优化前电磁转矩作比较，结果明显优于优化前，计算结果表明，该优化算法是正确的和有效的。第四，根据优化设计参数，画出图纸，制造了一台传动比为-4.25:1的Halbach阵列同心式磁力齿轮，磁力齿轮的铁损耗是其主要损耗，空载试验对其铁损耗进行了分析；而负载试验进行的是磁力齿轮传动装置在某一固定转速时，整个负载区间磁力齿轮传动装置的传递效率问题。从实验结果看，样机的电磁转矩密度和传递效率均较高，具有推广应用的价值。同心式磁力齿轮在采用Halbach阵列充磁方式下，气隙磁场相互迭加使得一侧的磁场强度大幅度提升，可以提高转矩密度；并且气隙磁场正弦分布程度较高，谐波含量小。为研究低转速大转矩磁力齿轮复合电机提供了可能。
[Abstract]:Halbach array concentric magnetic gears rely on magnetic field to transfer torque. The non-contact transmission between input and output makes them have the advantages of high torque density, high operating efficiency and overload protection. Compared with the traditional structure, it has greatly improved, so it has a good application prospect.
This subject is one of the research contents of the National Natural Science Foundation project "Research on Flux Decoupling Magnetic Variable Speed Permanent Magnet Brushless Motor" (51177097).
In this paper, the vector magnetic potential global analytic method is used to study the Halbach array concentric magnetic gear.
Firstly, the air gap magnetic field of concentric magnetic gear is calculated by two-dimensional global analytic method. The field is divided into three parts: inner and outer rotor permanent magnet, inner and outer air gap and slot region of magnetic stator, Laplace equation and Poisson equation of three sub-regions are connected by boundary continuity condition. The air gap magnetic field and the electromagnetic torque of the rotor are calculated by Maxwell stress tensor method. The air gap magnetic field waveform and the electromagnetic torque waveform of the rotor are compared with the waveform calculated by FEMM software. The results of the two layers are in good agreement. The harmonic magnetic field of air gap and the static characteristics of electromagnetic torque.
Secondly, according to the principle of Halbach array magnetization, the mathematical model of Halbach array magnetization is deduced, and the magnetic field and torque of inner and outer air gap of Halbach array concentric magnetic gear are calculated by global analytic method. The distribution of magnetic force lines under two kinds of magnetization methods is analyzed and compared. The results of global analytic method and FEMM are compared. The results are compared, and the air gap harmonic magnitude and torque under the two kinds of magnetization are compared. The waveforms calculated under the two kinds of magnetization agree well with the results calculated by finite element method, which lays a foundation for the parameter optimization design of magnetic gear.
Thirdly, in order to improve the torque density of magnetic gears, the genetic algorithm in MATLAB optimization toolbox is applied to the optimization design of magnetic gears for the first time. In the process of optimization, there is no artificial intervention, which is more convenient and fast than the optimization design of finite element method. As optimization variables, appropriate operators and probabilities are selected, and the range of parameters is determined according to the relationship between parameters and static torque. The electromagnetic torque of the optimized magnetic gear is calculated by global analytic method, and compared with the electromagnetic torque of the magnetic gear before optimization, the result is obviously better than that before optimization. The calculation results show that the optimization is superior to that before optimization. The algorithm is correct and effective.
Fourthly, according to the optimized design parameters, a Halbach array concentric magnetic gear with a transmission ratio of -4.25:1 is manufactured. The iron loss of the magnetic gear is the main loss, and the iron loss is analyzed by the no-load test. The load test is carried out in the whole load range of the magnetic gear transmission device at a fixed speed. From the experimental results, the electromagnetic torque density and transmission efficiency of the prototype are both higher, which is worthy of popularization and application.
In the case of concentric magnetic gears with Halbach arrays, the air-gap magnetic field overlaps with each other, which greatly improves the magnetic field strength on one side and increases the torque density; moreover, the air-gap magnetic field has higher sinusoidal distribution and lower harmonic content.
【学位授予单位】：上海大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH132.41;TM351

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