摘要
作为清洁能源汽车，电动汽车具有高能效，低噪音和零排放，成为世界新能源汽车发展的主要方向。而对于永磁同步电动机，其结构简单，运行效率高，功率密度高，调速性能优良，符合电动汽车用电动机的要求。因此，它在汽车工业中受到很多关注，并已广泛应用于电动汽车领域。本文在有限元分析的基础上，采用场路结合的设计方法进行了电动汽车用永磁同步轮毂电机的设计和运行特性分析。分析磁路结构参数变化对电机性能的影响，开发出适用于电动汽车的高效率、高功率密度、高过载能力的驱动电机，并由此总结了适用于电动汽车驱动的永磁同步电动机的设计方法，为后续系列产品的开发奠定了基础。本文的主要研究工作有以下几个部分：
根据电动汽车发展的关键技术，结合电动汽车的特殊运行条件和动力驱动特性，分析各种电动机性能的优缺点。本文选择内置永磁同步电动机作为研究对象，通过对其结构特点和工作原理的分析，确定设计任务目标，使设计突出电动汽车驱动电机的特性。
以有限元软件为基础，依据电机学和相关电磁场理论，本文采用场路结合设计方法，确定了电机的设计方案，进行了电机主要尺寸设计、绕组方案确定、极槽配合选择、永磁体参数计算、永磁体充磁方向分析、气隙长度的设计等工作，完成样机的初步设计方案；然后根据电机电磁设计方案，建立有限元求解模型，对电机进行有限元分析计算，主要是对电机的空载、负载及过载工况进行仿真，并在此基础上研究电机的
磁场分布、气隙磁密、空载反电动势、齿槽转矩、转矩转速以及永磁体涡流损耗等；研究相关结构的参数变化对电机的影响；从转子结构方面分析电机的弱磁扩速性能；为保证所设计的电机结构在运行时能够满足实际工况的机械强度需求，还对电机进行机械结构仿真，确保电机的各部分的应力能够满足所用材料的屈服强度的要求，保证电机的稳定运行。
最后依据设计结果制作了额定功率8.5kW、额定转速650r/min的样机，对样机的性能进行试验测试，测试结果表明样机具有较大的过载倍数和高效运行区域，达到预期设计目标。
关键词：电动汽车，永磁同步轮毂电机，电机设计，机械强度，有限元分析
ABSTRACT
As a clean energy vehicle, electric vehicle has become the important direction of the development of new energy vehicles in the world because of its high energy efficiency, low noise and zero emissions. Permanent magnet synchronous motor (PMSM) has attracted wide attention in the motor industry because of its simple structure, high efficiency, high power density and excellent speed control performance. It has also been widely used in the field of electric vehicles. Based on the application of finite element analysis and field-circuit combination design method, this paper analyzes the design and operation characteristics of permanent magnet synchronous hub motor for electric vehicles, analyzes t
he influence of magnetic circuit structure parameters on the performance of the motor, and develops a high efficiency, high power density, high overload multiple drive electricity suitable for electric vehicles. The design method of permanent magnet synchronous motor for electric vehicle is summarized, which lays the foundation for the later development of series products. The main research work of this paper is as follows:
According to the key technology of the development of electric vehicles and combing with the special operating conditions and driving characteristics of electric vehicles, this paper chooses interior permanent magnet synchronous motor as the research object. And through the analysis of its structure characteristics and working principle, this paper determines the design task objectives in order to making motor suitable for the electric vehicles.
Based on the finite element software and electromechanics and related electromagnetic field theory, this paper uses the field-circuit design method to determine the design scheme of the motor. In this paper, the preliminary design of the prototype is completed, including the main size design of the motor, winding scheme determination, pole-slot matching selection, permanent magnet parameter calculation, permanent magnet magnetization direction analysis, air gap length design and so on. Then according to the electromagnetic design scheme of the motor, the finite element solution model is esta
blished, and the finite element analysis and calculation of the motor are carried out, including the simulation of no-load, load and overload conditions. And based on the simulation, magnetic field distribution, air gap magnetic density, no-load back EMF, cogging torque, torque speed and permanent magnet eddy
current loss are analyzed. This paper also studies the influence of the structure parameters of the motor on the motor, and analyzes the performance of the motor from the rotor structure. In order to ensure that the designed motor structure can meet the actual operating conditions of the mechanical strength requirements, this paper also carries out the mechanical structure simulation of the motor to ensure that the stress of the various parts of the motor can meet the yield strength requirements of the materials to ensure the stable operation of the motor.
Finally, a prototype with rated power of 8.5 kW and rated speed of 650 r/min is made. The performance of the prototype is tested. The test results show that the prototype has a large overload multiple and high efficiency operation area, and achieves the expected design goals.
KEY WORDS:Electric vehicle, Permanent magnet synchronous in-wheel motor, Motor design, Mechanical strength, Finite element analysis
电动汽车电机目录
第1章绪论 (1)
1.1 论文的研究背景及选题意义 (1)
1.2 电动汽车驱动方式及特点 (2)
1.3 轮毂电机的两种驱动方式 (3)
1.4不同种类轮毂电机的技术特点 (4)
1.5国内外轮毂电机发展现状与发展方向 (6)
1.5.1国外轮毂电机研究现状 (6)
1.5.2国内轮毂电机研究现状 (8)
1.5.3轮毂电机技术发展方向 (9)
1.6本文主要研究内容 (9)
第2章电动汽车用永磁同步轮毂电机原理及关键技术 (11)
2.1永磁同步电机工作原理 (11)
2.2永磁同步电机数学模型 (13)
2.3外转子轮毂电机磁路结构分析 (15)
2.3.1表贴式磁路结构 (15)
2.3.2内置式磁路结构 (16)
2.3.3磁路结构的选择 (16)
2.4轮毂电机设计研究的关键点 (16)
第3章电动汽车用轮毂电机电磁方案分析与设计 (19)
3.1电动汽车动力性能分析 (19)
3.1.1电动汽车的驱动力 (20)
3.1.2电动汽车的行驶阻力 (21)
3.1.3电动汽车的动力性能要求 (22)
3.2电动汽车用轮毂电机电磁参数设计与计算 (23)
3.2.1主要尺寸的计算 (25)
3.2.2绕组方案的确定 (26)
3.2.3极槽配合的选择 (28)
3.2.4永磁体参数计算 (29)
3.2.5永磁体充磁方向分析 (31)
3.2.6气隙长度的设计 (32)
3.3样机基本参数 (32)
第4章电动汽车用永磁轮毂电机有限元分析 (35)
4.1电机电磁场分析的基础理论 (35)
4.2 有限元法的基本原理和电磁场有限元软件介绍 (36)
4.2.1有限元法基本原理 (36)
4.2.2电磁场有限元软件介绍 (37)
4.3轮毂电机有限元模型的建立与求解 (37)
4.3.1有限元模型建立 (37)
4.3.2电机材料选取与模型网格剖分 (38)
4.3.3求解及后处理 (39)
4.4轮毂电机电磁场有限元仿真分析 (39)
4.4.1空载磁场分析 (39)
4.4.2负载性能分析 (41)
4.4.3弱磁扩速性能分析 (42)
4.5轮毂电机机械结构分析 (43)
4.5.1轮毂电机机械结构有限元仿真模型的建立与求解 (43)
4.5.2轮毂电机机械结构有限元仿真模型有限元分析 (45)
第5章样机试验 (47)
5.1电机测试方法与内容 (47)
5.2测试结果 (48)
5.2.1空载试验 (48)
5.2.2负载试验 (49)
第6章总结与展望 (51)
6.1全文总结 (51)
6.2工作展望 (51)
参考文献 (53)
发表论文和参加科研情况说明 (57)
致谢 (59)