| 题名 | 磁悬浮超导球形转子的动力学特性研究; 磁悬浮超导球形转子的动力学特性研究 |
| 作者 | 1何川,电工研究所 |
| 学位类别 | 博士 |
| 答辩日期 | 2007-05-23 |
| 授予单位 | 中国科学院电工研究所 |
| 导师 | 1王秋良,电工研究所 |
| 关键词 | 超导球形转子 磁悬浮 悬浮力 转子动力学 干扰力矩 Superconducting spherical rotor, Magnetically-suspended, Force, Rotor dynamics, Perturbed torque |
| 其他题名 | 磁悬浮超导球形转子的动力学特性研究 |
| 中文摘要 | 超导体的零电阻和完全抗磁性被用来发展高精度的新一代陀螺仪。由于超导体的独特性能，低温陀螺能获得优良的稳定性，因为它工作在低温，在这个条件下，材料是化学惰性的，膨胀系数接近零，材料蠕变趋势降低，而且无接触的磁悬浮支承免除了磨损和摩擦，并且，一旦陀螺转子正常旋转以后，如线圈运行在永久电流模式，电源就可以断开，系统可以长时间稳定运转，可节约能源。此外，低温陀螺可以工作在极其恶劣的环境条件下。因此，作为一种高精度的惯性器件，具有巨大的发展前景，对于深海深空的应用具有极为重要的意义。本文侧重于低温陀螺仪磁悬浮球形转子的动力学特性的基础理论研究，并利用理论研究成果以半径为25mm的磁悬浮超导球形转子的工程实例为对象进行具体分析，在转子漂移的精度达到0.001°/h的前提下，对工程设计提出了特定的要求。研究工作主要集中在以下几个方面： 以经典的电磁力学理论为基础，从具有普遍意义的圆形线圈悬浮超导球的情况入手，推导了圆形线圈悬浮超导球体的受力分析模型。同时，利用具体的计算实例，对理论分析、实验结果和有限元仿真进行比较，结果吻合较好。然后，针对任意的悬浮磁场中的超导球体建立了悬浮力的计算模型：利用球谐函数表示悬浮磁场，并通过完全抗磁性决定的超导球表面的边界条件求出感应磁场，应用麦克斯韦应力张量表面积分计算转子受力，给出了线圈磁场的球谐函数表达式，同时导出了超导球在微小位移下的恢复力计算方法。 利用经典的刚体动力学理论，推导了理想超导球形转子的动力学方程，并分析了转子在无干扰时的自然规则进动规律；针对超导球形转子在实际工作中的小角度运动，分析了其定轴性、稳定性和进动性；推导了转子轴向偏心引起的转子漂移计算公式，建立了径向偏心引起的转子侧摆运动方程，利用超导球形转子相坐标方程组研究径向偏心引起的转子漂移，并建立了漂移的理论计算模型。还从理论上讨论了悬浮结构中残余气体对转子运动的影响，残余气体不会引起转子漂移，只会引起转子转速衰减。针对半径为25mm的磁悬浮超导球形转子，具体分析了其运动特性和在满足转子精度要求的前提下，转子轴向偏心和径向偏心要达到的水平。 转子产生干扰力矩的因素主要有三个方面：非球形、俘获磁通和伦敦磁矩。本文为非球形和俘获磁通产生的干扰力矩建立了详细的理论分析模型，对于伦敦磁矩产生的干扰力矩，从均匀磁场的情况入手，用微观和宏观的电磁理论，进行了具体的理论分析，并扩展到任意磁场的情形。然后利用这些干扰力矩计算的理论模型，结合半径为25mm的磁悬浮超导球形转子的具体实例，对转子受到的干扰力矩随着各种参数的变化趋势，转子的运动规律和转子的漂移做了具体的分析和讨论， 最后，针对悬浮结构中包含超导整形块的特殊结构对超导球形转子所受的干扰力矩进行了初步的理论探索，建立了转子干扰力矩的理论计算模型，分析了超导整形块的设计参数对干扰力矩的影响规律。 本文着重于超导球形转子的动力学特性的基础理论研究，所得的理论成果对于低温陀螺仪的磁悬浮超导球形转子的动力学问题具有广泛的适用性，同时对悬浮结构的设计、转子动力学的进一步研究以及转子漂移的测试和分析有着重要的意义。 The diamagnetic effect and the vanishing of resistance of superconductors open up the development of new generation gyroscope. Due to particular characteristics of superconductors, superconducting gyroscope can achieve excellent stability because it operates in cryogenic condition. In this circumstance, the materials used are chemically inactive, and expansion coefficients and creep properties greatly reduced, in the meantime, this no contacting magnetically suspension is free of abrasion and friction. Furthermore, once the rotor of gyroscope rotates at working speed, the suspending superconducting coils in which no decaying currents flow can operate without power supply. Accordingly much energy can be saved. In addition, the superconducting gyroscope can run in especially abominable working situations. Therefore, as a highly accurate inertial instrument, it has promising development and magnificent applications especially in deep-sea and deep-space circumstances. The research of this dissertation emphasizes on the basic theorems of dynamics for superconducting magnetically suspended spherical rotor. The result of this basic theoretical research is applied to analyze an engineering project including a rotor with a radius of 25mm. In order to satisfy the design accuracy of rotor's drift which is 0.001°/h, we put forward challenges to meet for the engineering design. The main works can be listed as following: To begin with the general case that the rotor is supported by a circular coil, the theoretic model to analyze the force has been obtained on the basis of the classic electromagnetic theory. The comparison has been performed through theoretic analysis, experiments and FEA simulations with regard to engineering examples. The results show better agreement. Besides, the calculation of the force acting a superconducting spherical rotor in an arbitrary magnetic field is developed. The method is obtained by expressing the magnetic field in a series of complete spherical harmonic functions, determining the induced field which satisfies the boundary condition regulated by diamagnetic effect. It is also shown how express the filed due to an array of coils in a series of spherical harmonics and computing restoring forces then the spherical rotor has a slight displacement. Based on classical rigid body dynamics, the dynamic equations for the ideal superconducting spherical rotor were obtained and the natural precession of rotor without disturbance is analyzed. Second, the motion of rotor during operation is limited at the small angular range actually. Then the analysis of axis inertia, precession and nutation of the rotor is completed. Thirdly, the computing formula for the rotor’s drift caused by axial component of the eccentricity is deduced. The theoretical mode of lateral motion as a result of radial component f the eccentricity is established. The drift calculation model is developed by making use of phase coordinates equations of the spherical rotor. In addition, effect on the motion of the rotor resulted from residual gas which can cause rotating speed attenuation but not rotor’s drift. The analysis of motion characteristic for the spherical rotor with a radius of 25mm is performed and the requirements of the axial component and radial component of rotor’s eccentricity to satisfy the rotor’s drift accuracy are discussed in detail. It is known that the principal perturbing factors leading to perturbed moments are nonsphericity of the rotor, the London moment due to its rotation, and also the trapped flux in the rotor. The analytical model of torque owing to nonsphericity and trapped flux has been developed. The analysis of torque acting on the rotor in uniform magnetic field resulted from London moment has been accomplished from microcosmic and macroscopically views respectively. The torque calculating model in an arbitrary magnetic field is extended as well. The variation in perturbed torque along with different parameters and motion characteristics of the spherical rotor with a radius of 25mm has been discussed in detail. Meanwhile, drift analysis for the specific example is performed. Finally, the theoretic model of perturbed torque on the rotor for the suspension system with specific superconducting correcting screens is established. In the meanwhile, the variation of perturbed torque for different design parameters of superconducting screens is analyzed. This dissertation concerns the fundamental theoretical research on the dynamics of superconducting magnetically suspended spherical rotor. The result of theoretical research in this paper can be widely applied to analyze dynamic problems of the spherical rotor of the cryogenic gyroscope. In addition, the research results achieved is important and helpful for the design of suspension system of the superconducting gyroscope, the further research on rotor’s dynamics and the testing and analysis of the rotor’s drift. |
| 语种 | 中文 |
| 公开日期 | 2010-10-18 |
| 页码 | 128 |
| 分类号 | TM1 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.iee.ac.cn/handle/311042/6708]  |
| 专题 | 电工研究所_其他部门_其他部门_博士学位论文 |
| 推荐引用方式 GB/T 7714 | 1何川,电工研究所. 磁悬浮超导球形转子的动力学特性研究, 磁悬浮超导球形转子的动力学特性研究[D]. 中国科学院电工研究所. 2007. |
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