基于模型参考自适应系统的电磁轴承支承转子不平衡量辨识及振动抑制

Unbalance Identification and Vibration Suppression for Support Rotor of Electromagnetic Bearing in Basis of Model Reference Adaptive System

针对电磁轴承支承转子质量不平衡引起的同频振动问题,提出了一种基于模型参考自适应系统(model reference adaptive systems,MRAS)的转子不平衡量辨识与在线补偿相结合的算法,该算法鲁棒性强且能够有效简化控制器结构。针对转子在两个轴承平面内的等效不平衡量,提出了基于模型参考自适应的不平衡量辨识算法,根据Popov超稳定性理论进行自适应律设计并通过设计相位补偿角保证辨识算法在全转速范围内的稳定性;针对模型误差和复杂工况带来的系统参数变化,根据辨识结果生成补偿电流的初始值,并利用同样的模型参考自适应算法对补偿电流进行在线微调,从而在保证补偿精度的前提下大大提高了算法的收敛速度。仿真分析和实验研究结果表明:所提算法能够使两端轴承处的转子振幅在0.2 s内迅速衰减并保持稳定,对振动位移中的转速同频分量抑制效果达到90%以上,且能够自适应转速的变化。所提算法能快速准确地抑制不平衡所引起的转子振动,可满足多种场合下对转子高回转精度的要求。

In the case of synchronous vibration caused by mass unbalance of electromagnetic bearing’s support rotor,an algorithm combining rotor unbalance identification with on-line compensation based on model reference adaptive systems(MRAS)is proposed,which is robust and can effectively simplify the controller structure.The rotor unbalance in two bearing planes is equivalent,so an unbalance identification algorithm based on model reference adaptive is proposed.Its adaptive law is designed according to the Popov hyperstability theory,and the stability in the full speed range is ensured by phase compensation angle;In view of the system parameter changes caused by model errors and complex conditions,the initial value of the compensation current is generated according to the identification results,and the same model reference adaptive algorithm is used to fine-adjust the compensation current online,thus greatly improving the convergence rate of the algorithm on the premise of accurate compensation.The results of simulation analysis and experimental study show that:by this proposed algorithm,rotor amplitude at both ends of the bearing can rapidly attenuate and maintain stable within 0.2 s,and the speed-frequency component in the vibration displacement can be suppressed by more than 90%.Moreover,the algorithm could adapt to the change of rotational speed.The proposed algorithm can quickly and accurately suppress the rotor vibration caused by unbalance,and satisfy the requirements for high rotation accuracy of the rotor in various scenes.