转子在静电支承系统中的转速衰减特性

高真空静电支承式旋转系统中,偏心转子在磁场和静电力矩作用下,产生转速衰减,从而降低了系统精度。该文建立了静电力矩的数学模型,确定了支承系统频率特性与静电力矩大小之间的关系。在此基础上设计了含陷波滤波器、带宽相对较低的支承系统,以改善其局部频率特性,消除静电力矩引起的转速衰减。实验给出了常规和改进支承系统的转速测量结果,并进行了比较,从中分离出静电力矩的大小。结果表明,通过改变支承控制系统局部频率特性,可以消除静电降速力矩,最终提高了转子转速的长期稳定性。

Speed attenuation of rotor in electrostatic suspension system

Magnetic and electrostatic torques will slow the rotation of an eccentric rotor electrostatically suspended in a high vacuum, which reduces the system's accuracy. A mathematical model of the electrostatic torque was used to analyze the relationship between the torque and the system frequency response. The suspension system was then redesigned with a lower bandwidth including a notch filter to improve its partial frequency response and to eliminate the speed attenuation aroused by the electrostatic torque. Speed measurements of the improved system verified that the electrostatic torque had been reduced. The results show that the electrostatic torque can be reduced to zero by modifying the partial frequency response of the suspension system to improve the long-term stability of the rotor's speed.