超导磁悬浮支承系统干扰力矩及漂移误差分析

在超导磁悬浮支承系统中, 如果被悬浮的超导球形转子是一个理想的球体, 并且是表现出完全的迈斯纳态, 那么由于球体的对称性, 就不会产生干扰力矩. 但实际的情况并非如此, 一般情况下, 超导球形转子总是存在加工制造误差, 且在高速旋转时总是存在离心变形, 因此转子的表面并不是理想的球面, 当超导转子悬浮在磁场中时, 沿转子表面法线方向的磁悬浮力, 不是完全通过转子质心, 将会产生磁支承干扰力矩, 从而引起转子的漂移误差. 本文从超导转子磁支承干扰力矩的物理机理出发, 对干扰力矩及其引起的漂移误差进行了分析, 包括转子非球形产生的一次干扰力矩、转子非球形与失中度和装配误差产生的二次干扰力矩, 并推导出了磁支承干扰力矩引起的漂移率计算公式, 代入转子参数计算出各种干扰力矩引起的漂移率大小, 为转子漂移测试和系统误差补偿提供了参考, 对于转子的结构优化设计具有指导意义.

Analysis of magnetic disturbance torque and drift error in a sup erconducting susp ension system

In a superconducting suspension system, the disturbance torque acting on the superconducting rotor may not be generated if the rotor is an ideal sphere and in the complete Meissner state. However, in fact there exist always spherical tolerance during manufacturing process of the sphere and the centrifugal distortion due to the high speed rotation. Therefore, the disturbance torque will be generated due to the magnetic levitation force not getting through the mass center of the rotor when the rotor is levitated in the magnetic field. Based on the physical mechanism of the superconducting-magnetic bearing, the disturbance torque and the drift error are analyzed. The disturbance torques include the main torque due to asphericity of the sphere, the second torque generated by the combination of asphericity, uncentering and assembly errors. The model of drift rate is also deduced and the drift rate is calculated by substituting the rotor parameters into the formula. This analysis provides a reference for the rotor drift testing and error compensation, and is instructive for the optimization design of the rotor structure.