电磁轴承用磁通控制型功率放大器力增益的研究

摘要

对提出的基于磁通观测器的磁通控制型功率放大器的力增益进行了理论及实验研究。首先简述了基于磁通观测器的磁通控制型功率放大器的结构和工作原理,利用磁通控制型功率放大器的状态方程,推导得到了力增益的理论模型。然后对力增益进行理论分析、有限元分析及在所建立的电磁力测量机构上进行了实验测量,根据模型得到的力增益理论分析值与有限元计算值及实验测量值进行比较分析,并通过参数辨识的方法对力增益进行了修正,给出了偏置为0.7T和0.5T下修正系数与气隙的关系。由于得到的力增益是在常态工作点附近线性化后得到的,所以实际工作点的变化对模型的精度会有影响,最后给出了工作点设置在气隙中点时,横梁位置、力增益理论计算值与有限元计算值三者之间的关系。%The force gain of the proposed flux-controlled power amplifier based on flux observer is studied theoretically and experimentally.First,the structure and principle of flux-controlled power amplifier based on flux observer is introduced briefly,and the mathematical model of force gain is derived by solving the state equation of flux-controlled power amplifier.Then,theoretical analysis,finite element analysis and the actual measurements in an electromagnetic force measurement device is carried on for the force gain,and the results of theoretical analysis,finite element analysis and the actual measurements is compared.By the parameter identification method,the model of the force gain is revised and the relationships between the correction factor and air gap are given when the bias flux are 0.7T and 0.5T.Due to the model of force gain is obtained by linearization near the operating point,so the changes of operating point have a greater effect on the accuracy of the model.Finally,the relationship among the beam position,the force gain theoretical value and the finite element method value is given,when the operating point is set at the midpoint of the air gap.