【作者】 严欣平；

【导师】 杨顺昌；

【作者基本信息】 重庆大学 ， 电气工程， 2008， 博士

【摘要】 无轴承永磁同步电机是将磁轴承技术与永磁同步电机有机结合的新型电机。它既有永磁同步电机功率大、寿命长、效率高和积小体等优势,又有避免了机械轴承的磨损和温升问题,拓展了永磁同步电机在高速和超高速领域的应用空间,其独具的悬浮机理和结构特点使之在一些高新技术领域具有传统电动机无法实现和替代的技术和经济优势,具有良好的应用前景。本文以面贴式无轴承永磁同步电机为重点,对无轴承永磁同步电机悬浮力模型、影响稳定悬浮的因素、电磁设计的特殊性、电机控制策略和转子偏心位移控制等问题进行了较深入研究。系统地论述了无轴承永磁同步电机的研究意义、国内外的研究现状和发展趋势。针对面贴式无轴承永磁同步电机的特点,深入分析了无轴承永磁同步电机的悬浮机理和运行特点,从麦克斯韦力原理和虚位移原理不同角度,综合考虑了永磁体、转矩绕组、悬浮绕组磁场和转子偏心等因素,分析和建立了面贴式无轴承永磁同步电机的悬浮力数学模型和电机的完整数学模型。借助Ansoft软件,利用有限元分析方法,对所建立的悬浮力数学模型进行了验证,并首次系统地从定子绕组电流、转子偏心、磁路饱和、齿槽效应和洛仑兹力等方面较深入地分析了对悬浮力的影响,研究了相关规律。针对无轴承永磁同步电机电磁设计中存在的特殊问题和设计特点开展研究,通过对无轴承永磁同步电机退磁问题,悬浮力与永磁体厚度、气隙长度的关系研究分析,推导出了考虑退磁效应的最大转矩电流和悬浮电流表达式,创新性的提出通过建立反映永磁体厚度、气隙长度、悬浮力间关系的规律函数来优化电机转子设计,有限元分析验证了其正确性。首次从系统角度分析总结了面贴式无轴承永磁同步电动机的设计特点,完成了研究项目样机的电磁设计。针对无轴承永磁同步电机的特点,利用永磁同步电机控制策略,通过对无轴承永磁同步电机转矩和悬浮力解耦控制可能的策略分析,改进了基于完整数学模型的转子磁场定向控制策略,仿真结果表明,该策略在无轴承永磁同步电机仿真研究中具有较好预测实际系统性能的功能。针对无轴承永磁同步电机转子偏心位移控制问题,在无轴承永磁同步电机悬浮力控制策略中引入了模糊PID控制策略和提出了基于可控悬浮力模型的、转子磁场定向的转子偏心位移直接控制新方法,仿真表明:该两种控制策略构成的悬浮力控制系统实现了更有效的无轴承永磁同步电机悬浮力控制性能。本论文所研究的面贴式无轴承永磁同步电机问题,是相关研究未提及或提及而未深入研究的问题,因此,其研究具有一定的理论和实际应用价值。更多还原

【Abstract】 Bearingless permanent magnet synchronous motor is a new type of motor combined with the magnetic levitation technology and permanent magnet motor, which has the advantages of high power of permanent magnet synchronous motor, long life, high efficiency and small size. What’s more, the wear and temperature rise of mechanical bearing can be avoided and the application space of the permanent magnet synchronous motor in the field of high speed and supper high speed has been expanded. The technical and economic advantages and a good prospect of application are obvious for its unique suspension mechanism and structure characteristics, which can not be replaced by the traditional electric motor.This dissertation focuses on a surface-mounted bearingless permanent magnet synchronous motor and the motor levitation force model, and the impact on the stability of the hanging, the features of electro-magnet design, motor control strategy and control of eccentric rotor displacement is deeply studied.The research significance of the bearingless permanent magnet synchronous motor, the recent research and development trends both at home and abroad is systematically discussed in the dissertation. Levitation mechanism and the operating feature of the bearingless permanent magnet synchronous motor have been analyzed. Considered the factors of permanent magnet, the field of windings and eccentric rotor, the mathematical model of levitation force and the complete mathematical model of surface-mounted bearingless permanent magnet synchronous motor have been analyzed and established from different point of views of Maxwell’s force principle and virtual displacement principle.With the help of Ansoft software, the established mathematical model of levitation force is verified by means of Finite Element Analysis. The impact of current stator windings, rotor eccentricity, saturation, cogging effect and Lorentz force on levitation force has been analyzed systematically and deeply for the first time. The related laws have been researched.The research on the special problems and design features existed in the electromagnetic design of the bearingless permanent magnet synchronous motor is conducted. By analyzing the relationships among the demagnetization of bearingless permanent magnet synchronous motor, levitation force and the thickness of the permanent magnet and air-gap length, the maximum torque current of the demagnetization effect and suspended current expression are derived. The optimization of rotor design by establishing the law of function which can reflect the thickness of permanent magnet, air-gap length and levitation force is creatively put forward, which is verified by Finite Element Analysis. For the first time, the design feature of surface bearingless permanent magnet synchronous motor from the perspective of the system is analyzed and the electromagnetic design of the research prototype has been completed.For the characteristics of bearingless permanent magnet synchronous motor and the control strategy of permanent magnet synchronous motor, the rotor field oriented control strategy based on a complete mathematical model is improved by analyzing the possible strategy of bearingless permanent magnet synchronous motor torque and levitation force decoupling control. The simulation result shows that the strategy has a better function to forecast the actual system performance in the simulation study of bearingless permanent magnet synchronous motor. To solve the problem of eccentric rotor displacement control of bearingless permanent magnet synchronous motor, the fuzzy PID control strategy is led into the suspension control strategy of bearingless permanent magnet synchronous motor. Meanwhile, the new method of direct control of eccentric rotor displacement based on accurate controllable force suspended model and rotor flux orientation is put forward. The simulation shows that a more effective levitation force control performance of bearingless permanent magnet synchronous motor has been achieved under the levitation force control system constituted by the two control strategies.So far, the research of the surface-mounted bearingless permanent magnet synchronous motor described in this dissertation is not mentioned or not researched further by others in this area. As a result, the study has its value both in theory and practical application.更多还原