谐波对磁悬浮转子运动轨迹的影响分析及仿真

与机械轴承支承的控制力矩陀螺相比,磁悬浮控制力矩陀螺具有转速高、寿命长、体积小、重量轻、精度高等优点,因此是大型航天器的理想执行机构。分析了磁轴承支承的陀螺转子在离心力与干扰力的作用下,其中心运动轨迹为圆,但由于谐波(主要为三次谐波)成分的存在,改变了陀螺转子中心运动轨迹(使其运动轨迹变成近似矩形或菱形)、功耗增加、引起高频干扰,并通过磁悬浮控制力矩陀螺的实验进行了验证。对于如何减小系统的功耗、提高磁悬浮转子控制系统的性能提供了理论依据。

Simulation Analysis of Influence of Third Harmonic Noise on Movement of Magnetically Suspended Rotor

The flywheel rotor supported by magnetic bearing with permanent magnet bias is to be used in single gimbal control momentum gyro (SGCMG), since magnetic bearing with permanent magnet bias has unique advantages of non-contact, elimination of lubrication, low power loss, automatic balancing capability, and controllability of bearing dynamics characteristics comparing with conventional ball bearings for attitude control. The flywheel rotor orbit supported by magnetic bearing in the SGCMG was analyzed and tested, and a mathematic model of third harmonic was proposed. Because of eccentricities and disturbances, a approximately circular shaped orbit was expected, but the third harmonic noise distorted rotor orbit, the approximately rectangular and diamond shaped orbit from different radial magnetic were observed, which demanded unnecessary voltage and current outputs from the control system. The reasons to cause harmonic noise were given.