中文摘要：

介绍了三自由度永磁和励磁混合磁轴承基本结构和悬浮力产生的工作原理；用等效磁路法对永磁和励磁混合磁轴承的磁路进行了分析，得出了悬浮力数学表达式；利用Matlab对磁轴承各自由度之间运动、磁路之间的耦合特性进行了计算分析，给出了三维网格图。理论分析表明各自由度在平衡位置附近时，运动之间没有耦合；各自由度控制磁通是相互独立的，磁路之间不存在耦合。试验表明：在不考虑运动、磁路耦合情况下，采用分散独立的PID控制方法，实现了磁轴承稳定工作，并且满足磁轴承性能控制要求。

英文摘要：

The configuration of magnetic bearings and the generation of magnetic suspension forces by permanent magnet biased with 3-degree of freedoms are introduced. The flux path is analyzed by using the method of equivalent magnetic circuit. The mathematic expressions of suspension forces are presented. The coupling characteristics of movement and magnetic circuit between radial and axial round balanceable position are calculated and analyzed. The 3-dimension gridding figures are given. The theoretical analysis shows that movement between 3-degree of freedoms round balanceable position has no coupling and the control fluxes between 3-degree of freedoms are unassisted. The results of experiments show that decentralized PID controllers meet demands of hybrid magnetic bearings when couplings of movement and magnetic circuit are neglected.