非磁饱和偏置下自传感主动电磁轴承的转子位移协同估计

Cooperative Rotor Position Estimation of Active Magnetic Bearings with Unsaturated Magnetic Bias

基于电磁轴承差动控制模式,首次提出一种转子位移的协同估计策略。在非饱和偏置磁通的条件下,相对磁极必有一个处于非饱和状态。通过对控制电流的极性判断来动态追踪没有饱和的磁极,始终采用未饱和磁极端所估计得到的转子位移作为系统反馈。论述了非饱和偏置磁通的基本原理,并给出了非饱和最大偏置电流的实验测量方法。在四自由度电磁轴承系统平台上,对提出的相对磁极协同位移估计策略进行了静态悬浮饱和实验以及动态悬浮旋转实验。实验结果证明,使用该策略的自传感电磁轴承系统具有更强的抗磁饱和能力,同时也间接地提高了电磁轴承系统抵抗外力扰动的能力,增强了系统的稳定性。

A strategy of cooperative position estimation is proposed based on the differential control mode of active magnetic bearings(AMBs). Given unsaturated magnetic bias, one of the opposing pole pairs must be unsaturated. The unsaturated poles could be tracked by the control current polarity. The position estimation from the unsaturated poles is always chosen as system feedback. Basic theory of unsaturated magnetic bias is discussed and the experimental method of measuring the maximum value of unsaturated current bias is presented. This cooperative position estimation is tested in the 4-DOF AMBs system. Static and dynamic suspension experiments are held to prove the feasibility of this method. Experimental results show that, the self-sensing AMBs system using this strategy exhibits stronger rejection to magnetic saturation. And this strategy proves the performance of force disturbance and increases system stability.