一种新型非晶铁芯混合磁通调制永磁直驱轮毂电机的研究

Electric vehicles have become a hot topic in automobile industry, because of its energy saving and environmental protection. Among the variety of electric vehicle driving motors, permanent magnet motors have been developed quickly and have found more and more widely applications, because of their high torque inertia ratio, high power density and efficiency. The permanent magnetic motor which is mounted on the wheel hub of electric vehicles, not only can improve the body space utilization, but also can reduce the mechanical transmission loss, and has more flexible driving characteristics. In this project a novel amorphous core hybrid-flux-modulated permanent magnet direct-drive in-wheel electric motor is proposed. The proposed motor breaks the traditional design rule which stipulates that the pole-pair number of the stator and the rotor must be the same. The motor has a special physical structure with iron segments in the air gap to modulate the magnetic field and its stator core and iron segments are made of a new material-amorphous alloy. It has the merit of having a low rated speed and yet the physical size is small. The motor has high power density and, because of the small stator slot number, the slot space can be used efficiently. In addition, the free space between segments offers good ventilation. All clip-clutch, mechanical gear and mechanical differential for this motor are eliminated; hence the overall reliability and efficiency are greatly improved. This project aims to develop the operating mechanism and basic design theory of the novel amorphous core hybrid-flux-modulated permanent magnet direct-drive in-wheel electric motor. The performance and the thermal field need to be validated by extensive computer simulation using 3D finite element method. In 3D magnetic field finite element analysis, using a parametric modeling method, and joining the motor optimal design algorithm, the motor structure size and motor performance optimization can be achieved. The final optimal results can be directly used for a prototype motor manufacturing. The concept of the proposed motor should be verified and rigorously tested on prototypes.

永磁电机因其高转矩密度、高功率密度和高效率等优点，在电动汽车驱动系统中得到了广泛的应用。将永磁电机安装在车轮轮毂内，既能提高车体空间的利用率，又能降低机械传动损耗，并具有更灵活的行驶驱动特性。本项目提出了一种具有较高功率密度，较低额定转速和较小几何尺寸的新型非晶铁芯混合磁通调制永磁直驱轮毂电机，它融合了径向磁通调制减速、轴向磁通调制减速和轴向磁场电机的拓扑结构，气隙中有分别起径向和轴向磁通调制作用的导磁模块，电机定子铁芯与导磁模块均采用非晶合金材料制成。本项目将首先研究该电机的机电能量转换机理、磁通调制原理和电磁设计原则等；然后重点研究并建立该电机的3D场路耦合有限元参数化仿真模型，电机的3D温度场仿真模型，结合电机优化设计算法，设计并试制一台原型电机，通过实验测试与3D有限元计算结果的对比分析，优化电机的结构与性能，促进该电机的工程应用。

本项目提出了一种新型非晶铁芯混合磁通调制永磁直驱轮毂电机，它融合了径向磁通调制减速、轴向磁通调制减速和轴向磁场电机的拓扑结构，气隙中有分别起径向和轴向磁通调制作用的导磁模块。该电机希望安装在车轮轮毂内，以实现电动汽车的轮毂直驱驱动，既提高车体空间的利用率，又降低机械传动损耗，还能有更灵活的行驶驱动特性。.本项目首先通过对多种类型磁通调制电机原理的研究，梳理出磁通调制的通用理论，即满足产生恒定电磁转矩条件的电机极对数、转速等的设计约束条件。并归纳出磁场调制电机拓扑结构特点：结构中的每一部分可以静止或旋转；每一部分可以有一套或两套通直流电或交流电的绕组；永磁体可以采用不同的放置形式；电机可以采用单/双定子，单/双转子。.其次，对硅钢/非晶铁芯混合磁通调制永磁电机的电磁设计与极槽配合进行了研究，优选出36槽6极配合作为研究电机的极槽配合。随后，建立了36槽6极电机3D有限元仿真模型、3D有限元参数化仿真模型，对电机调制块和永磁体的结构尺寸进行了参数化建模和有限元仿真计算，结合优化算法，得到了优化电机的尺寸参数。最后还建立了36槽6极750rpm混合磁通调制永磁电机无刷直流运行模式下的3D场路耦合有限元模型，搭建电机的外部控制电路，计算并比较了两种电机额定运行时的转矩与损耗特性。.然后，利用Workbrench软件，建立了硅钢/非晶铁芯混合磁通调制永磁电机的3D温度场模型，计算了电机空载和负载时的温度场分布，发现电机运行时的最高温度均出现在定子以及绕组的内侧偏中心的位置。.最后，试制了硅钢/非晶铁芯混合磁通调制永磁电机的实验样机，搭建实验平台，测试和研究该电机在空载、堵转和负载运行的性能以及影响该电机运行性能的因素，测试结果验证了混合磁通调制永磁电机原理的可行性。本项目的研究达到了原理验证、样机试制、控制策略研究及控制器设计实现等目标。