磁轴承超临界高速电机系统控制器设计

Controller design of a supercritical high speed motor system suspended by active magnetic bearings

磁轴承电机系统高速运行时,转子需超越其一阶弯曲临界,超临界控制器的设计非常关键。为设计出能有效阻尼一阶弯曲模态振动的控制器,首先需对高速电机转子系统进行动力学分析,建立系统状态空间模型,以此为基础开展控制器研究工作。由于实际模型参数与理论模型存在差异,且难以精确获取,在控制器设计中,采用了相位整形技术。通过该方法,可基于试验测定的模态频率值,设计结构简单的控制器,有效提升磁轴承系统对转子一阶弯曲临界振动的阻尼效果。仿真与试验结果均证明了控制器的有效性,最终实现转子系统在高于48 000 r.min-1的转速下,平稳超越一阶弯曲临界,并成功运行到81 840 r.min-1。

In a high speed motor system suspended by active magnetic bearings,the rotor should run above its 1st bending critical speed and a controller for supercritical operation is very important.Dynamic analysis was performed and a state space system model was built to design a controller to effectively provide damping for the 1st bending mode vibration.There is difference between the actual model and the theory model.The actual model can hardly be obtained,which makes the controller design difficult.A phase shaping method was then used and a controller with a simple structure was designed based on the rotor＇s eigenfrequency value obtained from experiments.The damping of the rotor＇s 1st bending mode is effectively improved.Simulation and experimental results prove the controller＇s effects,with a stable supercritical running speed of above 48 000 r/min and the highest speed of 81 840 r/min.