利用场路结合方法分析磁轴承悬浮力

Levitation force analysis of magnetic bearing by circuit-field combination method

针对磁轴承悬浮力分析比较复杂的问题,提出利用场路结合分析磁轴承悬浮力的方法。基于磁路法推导了径向磁轴承悬浮力的线性化模型,针对具体的磁轴承系统,利用有限元法分析了磁轴承能够满足线性化模型的偏置电流选择范围和磁轴承转子偏移范围,通过最小二乘法修正了线性化模型的电流刚度系数和位移刚度系数,并对超出线性化模型范围的悬浮力进行了分析,采用多项式拟合的方法推导了悬浮力的非线性模型。对所推导的磁轴承悬浮力模型进行了实验验证。分析及实验结果表明:由于磁饱和等因素的影响,利用磁路法推导的线性悬浮力模型已不能充分描述磁轴承悬浮力特性,通过场路结合方法推导的悬浮力模型能够更准确地计算磁轴承悬浮力。

For the analysis of magnetic force of magnetic bearings is complicated,a levitation force analysis of magnetic bearing based on field-circuit coupled method was used.Firstly,the linear expressions of magnetic levitation force was deduced based on the analysis of magnetic circuit,then the ranges of bias current and operating which can satisfy linear model were analyzed by means of the finite element analysis,through least square method the current rigidity coefficient and displacement rigidity coefficient were modified,and the nonlinear expressions of magnetic levitation force was deduced by polynomial approximation for exceeding linear model range,and finally the finite element method was verified by experiment.The analysis and experimental results show that due to the magnetic saturation and other factors,and the levitation force model which was deduced by using of the magnetic circuit method can not adequately describe the magnetic bearing levitation force characteristics,and the levitation force model which was deduced by field-circuit method can more accurately calculate magnetic bearing levitation force.