基于麦克斯韦张量法的交流磁轴承径向悬浮力建模

交流磁轴承具有无摩擦、无磨损、无需润滑、密封且成本低、损耗少、寿命长等优点,在高速运动场合、低速洁净工况场合都有潜在的应用前景.力求解决目前交流磁轴承径向悬浮力建模存在的不够精确、不够直接、不具有通用性等不足,提出了一种基于麦克斯韦张量法的交流磁轴承径向悬浮力建模方法,这种方法使得交流磁轴承建模准确、直接且具有通用性.采用基于麦克斯韦张量法的交流磁轴承径向悬浮力建模方法,建立了交流二自由度混合磁轴承的悬浮力数学模型,其表达式被证明与采用等效磁路法建立的悬浮力表达式形式一致(仅相差系数关系),表明所建模型的正确性及所提出方法的可行性.并在此基础上,针对建模过程中的关键环节,对该建模方法进行直接性与通用性分析.最后给出了基于交流二自由度混合磁轴承模型的实验系统控制框图,并设计了相关实验,对基于麦克斯韦张量法所建立的交流二自由度混合磁轴承悬浮力模型的正确性进行了实验验证,实验结果表明提出的建模方法较等效磁路法更具有精确性.

A novel modeling method for radial suspension forces of AC magnetic bearings

AC magnetic bearings have potential application prospects in high speed situations and low-speed lustration conditions with the advantages of no friction,no wear,no oil lubrication,seals,and low cost,low loss,long life and so on.For overcoming the shortcomings of modeling on radial suspension forces for AC magnetic bearing,such as imprecise model,and lack of directness and generality,a new radial suspension forces modeling method of AC magnetic bearing based on Maxwell tensor method is proposed in this paper,which makes modeling process accurate,direct and universal.The mathematical model of suspension forces for two degrees of freedom of AC hybrid magnetic bearing(HMB) is established with this proposed method,whose expression of suspension forces is proven to in accordance with the expression established by equivalent magnetic circuit method,(the only difference is the coefficient between them),so the correctness of the model and the feasibility of the method are verified by the results.Finally,the control block diagram of experimental system according to this model of two degrees of freedom AC HMB is presented and some related experiment is designed.The correctness of the suspension forces mathematical models of two degrees of freedom of AC HMB is verified by the experiment and the experimental results show that the proposed modeling method is more accurate than the equivalent magnetic circuit method.