零偏置电流磁轴承转子系统动态性能的试验研究

Experimental Investigation for Dynamic Characteristics of the Active Magnetic Bearing Rotor System with Zero Bias Current

建立5自由度磁悬浮轴承转子试验系统,分析有偏置和零偏置电流方式的工作原理,将5自由度零偏置电流方式应用于试验系统中,采用锤击法模态试验、基于频率响应函数的模型修正方法和系统高速旋转试验等方法研究该系统的动态性能,并与有偏置电流方式进行比较。研究结果表明,与有偏置电流方式相比,零偏置电流方式将导致控制参数的稳定区域、系统的模态阻尼以及磁轴承的刚度和阻尼明显减小,系统在各阶临界转速时的振幅较大,但系统仍然可以安全稳定越过第一阶弯曲临界转速。在实际应用中,合理的设计仍可保证零偏置电流磁悬浮轴承转子系统安全稳定运行,特别是在低速或载荷平稳等应用场合,零偏置电流方式能够使得系统具有较好的综合性能。

An experimental setup of five degree-of-freedom active magnetic beating （AMB） rotor system is built up. The modes of bias current and zero bias current are presented. Dynamic characteristics of the system with zero bias current are investigated by stamping modal test, method of model updating based on frequency response function （FRF） and actual operation of the system, and compared with the results of the system with bias current. The results show that, for the system with zero bias current, the stability region of control parameters, modal damping and stiffness and damping of AMB are reduced obviously and its vibration amplitudes in motion on the critical speeds are larger than the system with bias current, however it can still get across the first bending critical speed safely. If the design of the system is proper, the mode of zero bias current can be adopted in actual application, especially in the application of low rotation speed and stable load, so that the system has better over-all properties.