控制力矩陀螺用磁轴承磁力参数的辨识

Identification of magnetic parameters for magnetic bearings in control moment gyroscope(CMG)

提出一种实用的闭环辨识方法—磁中心变位移法,可以对控制力矩陀螺用磁轴承的磁力参数进行辨识。这种方法通过在磁中心处改变转子位移,得出不同位移时的电流值,再用这些值进行最小二乘辨识,得出所求的磁力参数。辨识出的电磁力模型中代入实际数据所得输出值与磁轴承实际输出数据非常吻合,证明了辨识所得磁力参数的准确性,并且用所得到的磁力参数指导磁轴承系统控制器参数的选择,使之更好地对磁轴承进行控制。实验证明,调整后的参数使转子在 30 060 r/mim 时仍能稳定地悬浮在给定位置,验证了所得磁力参数的准确性。

A close-loop identification method by changing magnetic-core displacement was presented, which could identify the magnetic-force parameters of magnet bearings used in CMG（control moment gyroscope）. The currents under various displacements could be found by changing the rotor＇s displacements at the magnetic-core, and then they were used to identify the parameters of magnetic force by LSM（Least Squares Method）. The result of identified magnetic force model using the actual data can match the output data of the magnetic bearing, which proves the rightness of identified parameters. Simulation study based on identified magnetic force model has helped to choose better parameters for the controller to improve dynamic performance of the system. Rotor of the CMG can be suspended stably when rotor speed reaches 30 060 r/min by using the improved parameters of the controller.