非线性电磁力作用下的转子不平衡响应和界限碰摩转速

摘要

对于电磁轴承支撑的转子系统，其动力学性能在很大程度上受到各种非线性因素的制约，如力与位移间的强非线性关系、有限的控制电流等。这些因素的近似线性化虽然简化了分析过程，但所得结果可能与工程实际偏离较大。本文讨论了由于电磁力和功放输出电流的非线性特性给转子系统的不平衡响应造成的影响，即转子的碰摩，并定义了系统的界限碰摩转速，给出了数值仿真结果，在此基础上讨论了提高系统碰摩转速的途径。%The dynamic characteristics of the rotor-bearing system supported by active magnetic bearings(AMB) are restricted to a great extent by various nonlinear factors such as strong nonlinear relation between force and displacement, limited control current, etc. The approximative linearization to factors, simplifying analysis process indeed, lead to the result that would possibly differ from the real fact. In the paper, both unbalance response and threshold speed of touch-rubbing of the system subjected to nonlinear magnetic forces and nonlinear output current of power amplifier are investigated, and the results of numerical simulation are presented. Methods for increasing the limit of touch-rubbing speed are also discussed.