【作者】 杨艳；

【导师】 邓智泉；

【作者基本信息】 南京航空航天大学 ， 电机与电器， 2010， 博士

【摘要】 利用磁轴承与电机定子结构的相似性,将磁轴承中用来提供径向悬浮力的悬浮绕组叠绕在开关磁阻电机定子上,就构成了同时具备驱动和磁悬浮支撑功能的无轴承开关磁阻电机。无轴承开关磁阻电机不仅拓宽了无轴承电机的理论和应用范围,继承和发挥了开关磁阻电机的高速适用特性及其对恶劣环境的适应性,而且由于其直接控制转子的径向位置,因而对由于不对称磁拉力而引起的定子振动和噪声问题有望起到抑制作用。本文以12/8结构的定子双绕组无轴承开关磁阻电机为研究对象,着重从定转子几何偏心、转子质量偏心以及控制方式等角度研究了其电磁振动。首先,在对前人成果深入研究的基础上,分析了无轴承开关磁阻电机的电磁力,改进了径向电磁力的数学模型。新模型不仅考虑了电机运行过程中的磁饱和以及转子的偏心位移,为电机运行状态的离线分析和电机的设计提供了更为可靠的理论依据;而且解决了以往模型不能用来计算单个定子极所受径向磁拉力的问题,为无轴承开关磁阻电机振动和噪声的预测和控制创造了条件。其次,由于电机运行时定转子偏心问题会导致单边磁拉力的出现,这会使开关磁阻电机本来就很严峻的振动和噪声问题更加恶化。本文基于定子周向振动理论和无轴承开关磁阻电机的径向力特点,通过Matlab/Simulink的系统仿真,分析了将无轴承技术引入开关磁阻电机后对不平衡径向力起到的补偿作用,指出无轴承开关磁阻电机较普通开关磁阻电机更适合于应用在要求低噪声的领域。接着,由于无轴承开关磁阻电机的旋转和悬浮是电机主绕组电流和悬浮绕组电流共同作用的结果,基于不同的控制策略计算出来的主绕组和悬浮绕组的磁势组合是不相同的,而绕组磁势的不同组合对定子极径向力及定子的振动有直接的影响,本文就从这个角度对现有的几种无轴承开关磁阻电机的控制策略进行了深入的分析。通过计算求得几种控制策略在不同转矩和径向负载情况下理想悬浮时的主绕组和悬浮绕组电流;并对其产生的径向力进行时域和频域分析;指出了利于减小定子振动的控制策略,为无轴承开关磁阻电机不同场合下控制策略的选择提供了依据;实验验证了理论分析的正确性。随后,针对由于机械不平衡等原因引起的转子质量偏心问题,本文采用基于最小均方(LMS)算法的自适应凹陷滤波器对转子质量不平衡带来的不平衡激振力进行了补偿。介绍了不平衡振动的产生和特点;详细介绍了自适应滤波器的原理及设计方法,分析了加入该滤波器后系统的稳定性,并对该方案进行了仿真分析及实验验证。最后,针对电机实际运行中存在的转子磁偏心情况,从电机本体的角度,研究了主绕组线圈在不同连接方式下转子偏心对气隙磁场和定子振动的影响。提出了利于减小无轴承开关磁阻电机振动和噪声的主绕组线圈联结方式。更多还原

【Abstract】 Taking the advantage of the similarity of magnetic bearings and motor structure, Bearingless Switched Reluctance Motor (BSRM) concentrates the magnetic suspension winding used to provide radial suspension force in the traditional Switched Reluctance Motor’s (SRM’s) stator, which is capable of rotating and magnetic suspension supporting functions. BSRM not only expands the theory and application scope of bearingless motor, inherits and exerts the high-speed feature of Switched Reluctance Motor (SRM) and its adaptability to harsh environment, but also, by initially controlling the radial position of the rotor, provides a new approach to solve the vibration and noise problems caused by asymmetric magnetic pull.This paper takes the 12/8 structure dual-winding BSRM as the object of study, and researches the magnetic vibration from the aspect of stator/rotor geometric eccentricity, rotor mass eccentricity and the controlling mode.From the in-depth study upon the previous research results, the mathematical model of BSRM is improved in this paper. The new model not only considers the magnetic saturation and the rotor eccentricity displacement of the motor during the running process, which has provided a more trusty basis to analysis motor’s running state and to design the motor; but also solves the problem that previous models cannot be used to calculate the radial magnetic pull upon a single stator pole, whichhas laid the foundation for the prediction and control of vibration and noises in the BSRM. Secondly, as the unilateral magnetic pull is caused by the problem of stator eccentricity, the serious problem of vibration and noise becomes even worse. Based on theory of circumferential vibration and the characteristics of radial force in BSRM, by the system simulation based on Matlab/Simulink, this paper analyzed the compensation function upon the unbalanced radial force after introducing the bearingless technology into SRM, and points out that BSRM is more applicable in the field with low noise requirement.Then, as the rotation and suspension of BSRM is the result of motor main winding current and suspension winding current working together, the different combination of main winding and suspension winding will have direct impact upon the stator radial force and stator vibration. This paper makes an in-depth analysis from this aspect upon the several existing control strategies of the BSRMs. This paper calculates out the main winding and suspension winding currents when motor is ideal suspension with the several control strategies under different torque and radial load; it makes the analysis of time domain and frequency domain upon the generated radial force; it points out the control strategy for reducing the stator vibration, and lays the foundation for the choice of control strategies of BSRM under different situations. Experiments in this paper also verifies the theoretic analysis.Later, for the problem of rotor mass eccentricity caused by mechanical imbalance, in this paper, the adaptable filter based on Least-Mean-Square (LMS) algorithm is adopted to compensate the imbalanced radial force. It introduces the generation and features of imbalanced vibration, introduces in detail the theory and design of adaptable filter, analyzes the stability after introducing this filter, and makes the simulation and experiment verification of this plan.Finally, for the problem of rotor magnetic eccentricity existing in the actual running of rotor, this paper researches the impact of rotor eccentricity upon airgap magnetic field and stator vibration when the main winding is under different connections. It proposes the combination of main winding that can reduce the vibration and noises of bearingless reluctance motor.更多还原