谐波注削式永磁电机的设计与分析

发布时间：2018-08-13 16:08

【摘要】：现如今永磁(Permanent magnet,PM)电机已经得到了广泛的应用,从电动汽车到航空航天等众多领域,永磁电机都扮演着十分重要的角色。这主要得益于永磁电机的几个显著优点,包括高转矩密度、高效率、出色的动力性能以及重量体积小等。永磁电机采用高磁能积的磁性材料取代传统的励磁绕组,不仅消除了励磁绕组带来的负面影响,而且简化了电机的机械结构,使电机运行可靠性提高,机械损耗也相应的减小了。然而,虽然永磁电机拥有一系列的优点,但对于转矩要求苛刻的高性能应用场合,如电动转向系统、伺服电机、风力发电机、速度和位置控制系统等仍然面临诸多挑战。上述这些应用都需要高质量的转矩输出性能,即高平均转矩和低转矩脉动。因此,如何提升平均转矩和减小转矩脉动是本文的重点研究内容。在阐明了永磁电机拓扑结构和工作原理的基础上,对影响电机输出性能的各项因素进行了分析,并对优化电机转矩性能的谐波注削法进行了深入的研究,提出了一种新的电机设计方法来获得最优的转矩输出性能,为设计高平均转矩和低转矩脉动的永磁电机提供了一种新的思路。基于以上的研究思路,本文的主要内容分为以下方面:1.通过解析法分析了表贴式永磁(Surface-Mounted Permanent Magnet,SPM)电机中气隙磁密的产生原理,阐明了永磁体的拓扑结构与气隙磁密分布的关系,为谐波注削法做出了理论解释。2.详细介绍了传统正弦式、反余弦式、正弦加三次谐波和反余弦加三次谐波四种谐波注削法,并使用有限元(Finite Element,FE)分析方法,对电机的电磁性能的进行了仿真验证。3.改进了上述四种谐波注削法的注削公式,使其能够广泛应用于永磁电机中的内定子、内转子、外定子和外定子。同时,改进后的公式不再受限于永磁电机,传统的直流无刷电机同样可以采用此类方法,拓展了这类方法的应用范围。4.研究了只在定子或转子一侧进行结构修形的单侧注削,以及定转子同时进行修形的双重注削。由于有四种不同的谐波注削法,因此双重注削会产生八种不同拓扑结构的电机。在对这些电机进行性能比较的基础上,总结出了一些规律性的结论。5.在对SPM电机解析的基础上,提出了一种新型的电机设计方法:反馈式谐波设计(Feedback Function Design,FFD)。在这种方法中,引入了黑盒理论来指导电机的设计。这种设计方法构建了一个具有输入参数、中间黑盒和输出参数的系统,通过调节输入参数改变永磁体拓扑结构,从而获得不同的性能输出。只要输入的数据库足够大,理所当然的可以获得目标电机的最佳性能。6.基于反馈式谐波设计制造了一台样机,构建了实验平台,通过实际测试来验证理论分析。
[Abstract]:Nowadays, permanent magnet (Permanent) motors have been widely used in many fields, such as electric vehicles, aerospace and so on. This is mainly due to several outstanding advantages of permanent magnet motors, including high torque density, high efficiency, excellent dynamic performance and small weight and volume. The permanent magnet motor uses magnetic material with high magnetic energy product to replace the traditional excitation winding, which not only eliminates the negative influence of the excitation winding, but also simplifies the mechanical structure of the motor and improves the reliability of the motor operation. The mechanical loss is also reduced accordingly. However, although the permanent magnet motor has a series of advantages, there are still many challenges for the high performance applications with demanding torque, such as electric steering system, servo motor, wind turbine, speed and position control system and so on. These applications require high quality torque output performance, that is, high average torque and low torque ripple. Therefore, how to increase average torque and reduce torque ripple is the focus of this paper. On the basis of expounding the topology and working principle of permanent magnet motor, the factors influencing the output performance of permanent magnet motor are analyzed, and the harmonic injection method to optimize the torque performance of the motor is studied deeply. A new motor design method is proposed to obtain optimal torque output performance, which provides a new idea for the design of permanent magnet motor with high average torque and low torque ripple. Based on the above research ideas, the main content of this paper is divided into the following aspects: 1. The generation principle of air gap magnetic density in Surface-Mounted Permanent permanent magnet (Surface-Mounted Permanent) motor is analyzed by analytical method. The relationship between the topology structure of permanent magnet and the distribution of air gap magnetic density is clarified, and the theoretical explanation of harmonic injection method is given. Four kinds of harmonic injection methods, traditional sinusoidal, inverse cosine, sinusoidal plus third harmonic and inverse cosine plus third harmonic, are introduced in detail. The electromagnetic performance of the motor is verified by using the finite element method (Finite element FE). The four harmonic injection formulas mentioned above have been improved so that they can be widely used in the inner stator, inner rotor, outer stator and outer stator of permanent magnet motor. At the same time, the improved formula is no longer limited to the permanent magnet motor, the traditional brushless DC motor can also use this method, which extends the application range of this method. The single side injection of the stator or rotor and the double injection of the stator or rotor are studied. Because there are four different harmonic injection methods, eight different topologies can be generated by double injection. On the basis of comparing the performance of these motors, some regular conclusions. Based on the analysis of SPM motor, a new design method of motor is proposed: feedback harmonic design (Feedback Function design). In this method, the black box theory is introduced to guide the design of the motor. This design method constructs a system with input parameters, middle black box and output parameters. By adjusting the input parameters, the topology of permanent magnet is changed to obtain different performance outputs. As long as the input database is large enough, you can naturally get the target motor's best performance. 6. A prototype is designed and manufactured based on feedback harmonic, and the experimental platform is constructed, and the theoretical analysis is verified by practical test.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM351

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