制造误差对磁力轴承动态特性的影响研究

发布时间：2018-05-04 08:22

本文选题：磁力轴承 + 制造误差　；参考：《武汉理工大学》2011年硕士论文

【摘要】：主动磁力轴承系统是由机械和电气两大部分组成的典型机电一体化系统,系统稳定工作需要机械部分和控制部分共同作用,其中需要引入反馈控制。当主动磁力轴承机械部分加工完成后,其性能主要取决于电气控制部分,但机械部分的制造误差对主动磁力轴承的性能也有很大的影响,而误差本身在制造过程中是不可能完全消除的。对于静态、低转速及低精度的磁力轴承应用,制造误差的影响较小,可以忽略。但近年来,对磁悬浮转子的转速和旋转精度的要求越来越高,而制造误差对高转速下的旋转精度影响较大,进而对控制系统要求更高。追求高的制造精度,必将增加加工成本与难度,影响磁力轴承市场化的前景。因此,设计一套高精度的磁力轴承系统,制造误差对磁力轴承动态特性的影响是不可忽略的问题。从高速转子的误差特性出发,分析转子的几何误差和回转运动误差,掌握这些误差的基本特征、评定方法及测量方法对研究磁悬浮转子的误差特性起指导作用；并在此基础上,分析了主动磁力轴承系统主要结构的常见制造误差,用结构示意图直观描述这些误差形式,讨论了误差的形成原因及对磁力轴承系统带来的影响；研究两自由度磁力轴承系统的制造,对比主要结构的设计与制造后的尺寸、形位精度,发现存在较大误差,无法满足设计精度。重点分析传感器检测表面圆度误差对主动磁力轴承系统的动态特性影响,推导了圆度误差、控制电流、位移刚度和电流刚度的关系方程,定量分析了不同误差精度等级,不同结构参数下圆度误差对主动磁力轴承动力学特性的影响程度,,以及对常规PID控制下磁力轴承系统阶跃响应的影响；将圆度误差信号引入到控制系统的反馈环节，仿真分析误差对磁力轴承的动态特性的影响。本文最后考虑磁力轴承系统加工和装配误差引起的几何中心不重合误差,分析了几何中心误差的形成原因,以及径向、轴向几何中心误差对磁力轴承的动态特性的影响；基于中心误差的形成原因,提出了一种几何中心误差的实验检测方法,探讨了改善几何中心误差的工艺措施,为此类磁力轴承系统提供了制造指导。
[Abstract]:Active magnetic bearing system is a typical mechatronics system composed of mechanical and electrical parts. The stability of the system needs the interaction of the mechanical part and the control part, and the feedback control is needed. When the mechanical part of the active magnetic bearing is finished, its performance mainly depends on the electrical control part, but the manufacturing error of the mechanical part also has a great influence on the performance of the active magnetic bearing. The error itself can not be completely eliminated in the manufacturing process. For static, low speed and low precision magnetic bearings, the effect of manufacturing error is small and can be ignored. However, in recent years, the requirements of rotational speed and precision of maglev rotor are more and more high, and the manufacturing error has a great influence on the rotation accuracy at high speed, and then requires higher control system. The pursuit of high manufacturing precision will increase the processing cost and difficulty and affect the prospect of marketization of magnetic bearings. Therefore, it is not negligible to design a set of high precision magnetic bearing system, and the influence of manufacturing error on the dynamic characteristics of magnetic bearing can not be ignored. Based on the error characteristics of high speed rotor, the geometric error and rotation error of rotor are analyzed, the basic characteristics of these errors are grasped, the evaluation methods and measurement methods are used to guide the study of the error characteristics of maglev rotor, and on this basis, The common manufacturing errors of the main structure of active magnetic bearing system are analyzed. The forms of these errors are described intuitively by the structure diagram. The causes of the errors and their influence on the magnetic bearing system are discussed. This paper studies the manufacture of two degrees of freedom magnetic bearing system, compares the design of main structures with the dimensions and position accuracy of the main structures, and finds that there are large errors which can not meet the design accuracy. The influence of roundness error of sensor on dynamic characteristics of active magnetic bearing system is analyzed emphatically. The relation equations of roundness error, control current, displacement stiffness and current stiffness are derived, and different error precision grades are quantitatively analyzed. The influence of roundness error on the dynamic characteristics of active magnetic bearing and the step response of magnetic bearing system under conventional PID control under different structural parameters are discussed, and the roundness error signal is introduced into the feedback link of the control system. The effect of error on the dynamic characteristics of magnetic bearing is analyzed by simulation. In the end of this paper, the geometric center error caused by machining and assembling errors of magnetic bearing system is considered, and the causes of geometric center error are analyzed, and the influence of radial and axial geometric center error on the dynamic characteristics of magnetic bearing is analyzed. Based on the forming reason of the center error, an experimental detection method of the geometric center error is put forward, and the technological measures to improve the geometric center error are discussed, which provides the manufacturing guidance for this kind of magnetic bearing system.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH133.3

【相似文献】