为使磁悬浮飞轮具有高精度、大力矩、多自由度动量交换能力,提出并设计了一种永磁偏置轴向磁轴承(AGMB),主动控制飞轮转子沿轴向平动和绕径向偏转这3个自由度的运动。提出偏置磁通耦合度、控制磁通耦合度的概念,并给出了定义。通过磁路分析得到了AGMB和应用于微动框架的传统永磁偏置径向磁轴承(即径向力偏转磁轴承,RGMB)的耦合度的解析表达式,建立了磁路模型与磁路耦合程度之间的数值公式联系,进而定量分析了磁路耦合度对决定飞轮微动框架性能的偏置力变化率、电流刚度变化率以及最大承载力等磁轴承性能指标的影响,为解析分析和评价磁轴承的磁路耦合特性及其对磁轴承性能的影响提供了一条理论途径。经解析计算和有限元(FE)仿真验证表明,AGMB具有更好的磁路弱耦合特性和偏转性能:微动框架时磁路耦合度的变化范围较RGMB小近一个数量级,从而偏置力变化率、电流刚度变化率的变化范围小近一个数量级,飞轮最大偏转力矩指标是RGMB的2.7倍以上。基于AGMB所设计的50 N·m·s磁悬浮飞轮,可实现最大偏转角0.5°、最大偏转力矩8.1 N·m、偏置力与电流刚度的变化率全工况下不超过15%的大容量、高精度的微动框架功能。
To satisfy the requirements of the high precision vernier-gimballing function of a magnetically suspended flywheel, an axial magnetic bearing biased with a permanent magnet, i.e., the axial gimballing magnetic bearing (AGMB ) is presented, with the capacity of controlling the 3 degrees of freedom rotor motion including axial translation and radial tilt. The concepts of bias-flux coupling degree and control-flux coupling degree are introduced and defined. Based on the coupling degree analytical expression of AGMB and the traditional radial magnetic bearing biased with a permanent magnet (called radial gimballing magnetic bearing applied for vernier-gimballing, RGMB for short) from an equivalent magnetic circuit, the quantitive relationship between the magnetic circuit model and the coupling degree is constructed, and the coupling degree influence on the magnetic bearing performance, such as its bias-force change rate, current stiffness change rate, and maximal loading ability, is obtained to further decide flywheel vernier-gimballing performance. This opens a theoretical path for the analysis and evaluation of magnetic flux coupling and magnetic bearing performance. It is verified by magnetic-circuit analysis and finite element (FE) simulation that the coupling degree and bias-force change rate, current stiffness change rate of AGMB are nearly one order less than those of RGMB, and the maximal gimballing moment of flywheel is 2.7 times larger. As a result, a 50 N·m·s flywheel based on AGMB has the large and high precision gimballing capacity of 0.5° maximal gimballing angle, 8.1 N·m maximal gimballing moment, and less than 15% of bias-force change rate and current stiffness change rate over all the statues.
[1] Park J, Palazzolo A, Beach R. Integrated power and attitude control (IPAC) of a satellite via magnetic bearing supported, flexible shaft flywheels. AIAA-2006-6803, 2006.
[2] Bichler U J. A low noise magnetic bearing wheel for space application//Proceedings of the 2nd International Symposium on Magnetic Bearings. 1990.
[3] 盖振伟. 多自由度动量交换技术研究的新进展[J]. 航天控制, 2006, 24(6):84-89. Ge Zhenwei. Latest development of momentum exchange technology with multi-degree of freedom[J]. Aerospace Control, 2006, 24(6):84-89. (in Chinese)
[4] 吴刚, 张育林, 刘昆, 等. 万向磁悬浮动量轮研究[J]. 中国空间科学技术, 2004(4):30-35. Wu Gang, Zhang Yulin, Liu Kun, et al. Study for gimbal magnetic suspension momentum wheel [J]. Chinese Space Science and Technology, 2004(4):30-35. (in Chinese)
[5] Fang J C, Sun J J, Xu Y L, et al. A new structure for permanent-magnet-biased axial hybrid magnetic bearings[J]. IEEE Transactions on Magnetics, 2009, 45(12):5319-5325.
[6] 刘彬, 房建成, 刘刚, 等. 磁悬浮飞轮不平衡振动控制方法与试验研究[J]. 机械工程学报, 2010, 46(12):188-194. Liu Bin, Fang Jiancheng, Liu Gang, et al. Unbalance vibration control and experiment research of magnetically suspended flywheels[J]. Journal of Mechanical Engineering, 2010, 46(12):188-194. (in Chinese)
[7] Gerlach B, Ehinger M, Raue H K, et al. Digital controller for a gimballing magnetic bearing reaction wheel. AIAA-2005-6467, 2005.
[8] 刘虎, 房建成. 新型永磁偏置轴向磁轴承的磁力特性[J]. 机械工程学报, 2010, 46(8):167-174. Liu Hu, Fang Jiancheng. Magnetic force characteristics of a novel permanent magnet biased axial magnetic bearing[J]. Journal of Mechanical Engineering, 2010, 46(8):167-174. (in Chinese)
[9] Sawada H, Hashimoto T, Ninomiya K. High-stability attitude control of satellites by magnetic bearing wheels. AIAA-2000-4544, 2000.
[10] Chen H M, Walter T, Chapman P, et al. Recent development of magnetic bearings for flywheel energy storage. AIAA-2003-6105, 2003.
[11] Lin L C, Gau T B. Feedback linearization and fuzzy control for conical magnetic bearings[J]. IEEE Transactions on Control Systems Technology, 1997, 5(4):417-426.
[12] 赵旭升, 邓智泉, 王晓琳, 等. 永磁偏置磁轴承的研究现状及其发展[J]. 电工技术学报, 2009, 29(9):9-20. Zhao Xusheng, Deng Zhiquan, Wang Xiaolin, et al. Research status and development of permanent magnet biased magnetic bearings[J]. Transactions of China Electrotechnical Society, 2009, 29(9):9-20. (in Chinese)
[13] Zhilichev Y. Analysis of a magnetic bearing pair with a permanent magnet excitation[J]. IEEE Transactions on Magnetics, 2000, 36(5):3690-3692.
[14] Zong M, Liu Y H, Shen J X, et al. Force analysis for hybrid radial magnetic bearing biased by permanent magnet//Proceedings of the Eighth International Conference on Electrical Machines and Systems. 2005:1834-1837.
[15] 董宏林, 王子华, 段广仁, 等. 比例电流条件下整体四磁极电磁轴承耦合分析[J]. 哈尔滨工业大学学报, 2007, 39(11):1814-1817. Dong Honglin, Wang Zihua, Duan Guangren, et al. Analysis of electromagnetic coupling of 4-pole integrated magnetic bearing under proportional current[J]. Journal of Harbin Institute of Technology, 2007, 39(11):1814-1817. (in Chinese)
[16] 孙玉坤, 朱熀秋, 蔡兰. 三自由度混合磁悬浮轴承耦合特性[J]. 江苏大学学报:自然科学版, 2006, 24(7):432-436. Sun Yukun, Zhu Huangqiu, Cai Lan. Coupling characteristics of hybrid magnetic bearings with three-degree of freedom[J]. Journal of Jiangsu University:Natural Science Edition, 2006, 24(7):432-436. (in Chinese)
[17] Liu B, Fang J C, Liu G. Gimballing control and its implementation for a magnetically suspended flywheel//Proceedings of the 12th International Symposium on Magnetic Bearings. 2006:161-166.
[18] Han B C, Fang J C. Design of magnetic bearing reaction wheel for high precision attitude control of spacecraft//Proceedings of the 10th International Symposium on Magnetic Bearings. 2006.
[19] Polajer B, tumberger G, Ritonja J, et al. Impact of magnetic nonlinearities and cross-coupling effects on properties of radial active magnetic bearings[J].IEEE Transactions on Magnetics, 2004, 40(2):798-801.
[20] Polajer B, tumberger G, Dolinar D. Numerical analysis of radial active magnetic bearings//12th International Power Electronics and Motion Control Conference. 2006:1913-1918.
[21] Li Y, Li W, Lu Y P. Computer-aided simulation analysis of a novel structure hybrid magnetic bearing[J]. IEEE Transactions on Magnetics, 2008, 44(10):2283-2287.
[22] 房建成, 杨磊, 孙津济, 等. 一种新型磁悬浮飞轮用永磁偏置径向磁轴承[J]. 光学精密工程, 2008, 16(3):444-451. Fang Jiancheng, Yang Lei, Sun Jinji, et al. Novel permanent magnet bias radial magnetic bearing used in magnetically suspended flywheel[J]. Optics and Precision Engineering, 2008, 16 (3):444-451. (in Chinese)
[23] Huang L, Zhao G Z, Nian H, et al. Modeling and design of permanent magnet biased radial-axial magnetic bearing by extended circuit theory //Proceedings of International Conference on Electrical Machines and Systems. 2007:1502-1507.
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