【作者】 李睿；

【导师】 曲荣海；

【作者基本信息】 华中科技大学 ， 新能源科学与工程， 2021， 硕士

【摘要】 随着工业与科技的发展,各行各业对高端电动伺服系统的需求日益增长。作为伺服系统的执行机构,衡量伺服电机最关键的两个性能指标为转矩密度与齿槽转矩,其中前者决定了伺服系统响应速度的上限,后者则直接影响伺服系统的定位精度。永磁电机凭借结构简单、转矩密度大、可靠性高、效率高等优点,已逐渐成为伺服电机中的主流。传统有铁心永磁电机受到其固有的齿槽转矩作用,难以适应高精度场合;而无铁心永磁电机的受到磁密的限制,转矩密度难以提升,使伺服系统的造价直线上升。永磁游标电机是一种近年来新出现的一种拓扑,相较于传统永磁电机而言具有更高转矩密度与更低的转矩脉动,因此在伺服领域有广阔的发展前景。但永磁游标电机本质上还是有铁心永磁电机,仍受到齿槽转矩的限制,难以真正地走向高端伺服领域。为了进一步降低永磁游标电机的齿槽转矩,本文在传统永磁游标电机的基础上,创新性地提出了分数极永磁游标电机,并通过理论分析与有限元仿真对这一类电机拓扑开展了全面的研究,并取得了一系列成果。首先,本文介绍了分数极永磁游标电机的拓扑结构及其演变过程,并基于电机的槽矢量星形图,提出了分数极永磁游标电机中槽极配合可行性的判断方法,推导了分数极永磁游标电机的绕组系数计算方法。其次,本文将分数极永磁游标电机的齿槽转矩分为开槽分量与端部分量,并根据其产生原理的不同采取不同的优化手段,同时给出了分数极永磁游标电机的设计流程图,并将所设计的分数极永磁游标电机与传统永磁同步电机、无铁心永磁同步电机、传统永磁游标电机相比较,发现分数极永磁游标电机在齿槽转矩、额定转矩以及经济性等性能上都有突出表现。最后,本文根据所设计的分数极永磁游标电机,制作了样机并完成测试,针对样机的齿槽转矩中非理想的谐波次数,本文借助解析计算对造成这些谐波的部分加工误差进行了定位,通过有限元仿真研究了这些齿槽转矩与相应的加工误差之间的关系,介绍了一种基于复频域分析的误差复现方法,并通过这一方法还原了样机内的部分误差。更多还原

【Abstract】 With the development of industry and technology,the demand for high-end servo system in various industries is growing rapidly.As the actuator of servo system,the two key performance indexes of servo motor are torque density and cogging torque.The torque density determines the response speed of the servo system,and the cogging torque directly affects the positioning accuracy of the servo system.Benefit from the simple structure,high torque density,high efficiency and high reliability,permanent magnet motors(PMM)occupy the majority of servo motors.Suffers from the cogging torque,conventional PMM is difficult to adapt to highprecision applications.While the torque density of the ironless PMM is low due to its low flux density,making the servo system very expensive.Permanent magnet vernier machine(PMVM)is a new topology with inherent higher torque density and lower cogging torque compared to the conventional PMM,which brings the PMVM a broad application prospect.However the PMVM still suffers from the cogging torque because there are still teeth on its stator.This limits the application of PMVM in high-end servo field.Based on the PMVM topology,a novel fractional pole-pair permanent magnet machine(FP-PMVM)is proposed to further reduce the cogging torque.The FP-PMVM is studied comprehensively through the theoretical analysis and finite element analysis(FEA).Firstly,the topology and evolution of the FP-PMVM are introduced in this paper.Based on the slot vector diagram,a method to estimate the feasibility of the slot-pole combinations in FPPMVM is induced,as well as the calculation method of the winding factor.Secondly,the cogging torque of the FP-PMVM is divided into the slotting component and the end component,which are optimized by different means.The design process of the FPPMVM is given and the designed FP-PMVM is compared with a conventional PMM,an ironless PMM and a PMVM.It is found that the FP-PMVM has good performance in both electromagnetic and economic aspects.Finally,a prototype of the FP-PMVM is manufactured and tested.The machining errors will lead to some cogging torque harmonics that will not appear in ideal situation.Some of these machining errors are located with the help of theoretical analysis and analytical calculations.The relationship between the cogging torque and the corresponding machining error is studied by the FEA.An error orientation method based on complex frequency domain analysis is introduced,and some errors in the prototype are located by this method更多还原