一种五自由度磁悬浮轴承系统的零功耗策略研究

Study on Zero Power Control Method of a Five Degrees Freedom Magnetic Suspension Bearing System

提出了一种低功耗五自由度磁悬浮轴承系统,其利用永磁偏置轴向磁轴承实现轴向悬浮,利用永磁磁力轴承实现径向悬浮。为进一步降低系统功耗,提出了使轴向磁轴承转子铁心偏移的零功耗控制策略,实时辨识出转轴轴向所受外力,求解出相应的转子铁心偏移位移,使转子铁心平衡位置发生变化,利用偏置磁场产生的被动磁力与外力相抵消,最终实现轴向磁轴承零功耗运行。利用MATLAB仿真软件对控制策略进行了仿真分析,结果表明,在给定外力的情况下,磁轴承的控制电流收敛到零。

In this paper a five degrees freedom magnetic suspension bearing system was proposed,which was combinedwith a permanent magnet biased axial magnetic bearing to suspend the rotor in axial direction and permanent magnet biasedradial magnetic bearings to do in radial directions. In order to reduce the power consumption of the system,a low-powercontrol strategy was presented that makes an offset displacement of the axial magnetic bearings rotor. Real-time estimationof the rotor stress in axial direction was the first step of the strategy, and then the offset displacement of the rotor iron corewas solved. Based on the offset displacement,the given displacement of the iron core was changed to balance the stress withthe passive magnetic force from biased magnetic field, which makes the low-power operation come true. The MATLAB sim-ulation of this control strategy shows that the control current of magnetic bearings converges to zero when the rotor with givenstress.