异极式永磁偏置径向磁轴承的建模与实验

Modeling and Experiment of Permanent Magnetic Biased Radial Heter-Polar Magnetic Bearing

为了满足储能飞轮系统、卫星动量轮等对高空间利用率的需求,提出了一种异极式永磁偏置径向磁轴承的拓扑结构。通过在槽口放置平行充磁的永磁体获得紧凑的结构,同时永磁磁路和电励磁磁路耦合距离较短,有利于获取高解耦特性。该文首先采用磁力线法,分别获取考虑齿槽效应、转子偏心的永磁磁场、电励磁磁场的气隙磁通密度分布,建立了磁路模型;然后根据磁路模型求解位移刚度和电流刚度,建立磁轴承的数学模型;与有限元仿真进行对比,证明所建立的磁场模型能够准确计算气隙磁通密度分布。设计、制造一台实验样机并进行相关实验,实验结果验证了磁路模型及有限元仿真的可靠性。

For the requirements of the flywheel energy storage system and the satellite momentum wheel about high space utilization, a novel permanent magnet （PM） biased radial heter-polar magnetic bearing （RHMB） is proposed. The permanent magnet of parallel magnetization is placed to the slot to get the compact structure, meanwhile, good decoupling characteristics is acquired because of the shorter coincident circuit between electro-magnet and permanent magnet. Firstly, the magnetic line of force equivalent model is applied in paper to get the distribution of the electro-magnetic or permanent-magnetic gap flux density considering slot effect and rotor eccentricity, and then a precise magnetic circuit model is built. The force-displacement and force-current relationships are acquired by the magnetic circuit model, the linear mathematics model built. The finite element analysis results show that the magnetic circuit model can get the distribution of the gap flux density accurately; after a prototype designed and manufactured, the experiment is performed and the results proved that the magnetic circuit model and the finite element analysis were effective.