径向-轴向共用偏磁电流的主动磁轴承建模与特性分析

Modeling and Performance Analysis for Radial-axial Active Magnetic Bearing with Sharing Biased Current

介绍了一种新的径向-轴向共用偏磁电流的主动磁轴承结构及工作机理,采用等效磁路法对该轴承的磁路进行了计算,得到了悬浮力数学模型。根据最大悬浮力要求设计了试验样机参数,并利用Matlab软件对磁轴承轴向、径向悬浮力的非线性和各自由度之间在平衡位置附近的运动以及径向-轴向之间的磁路耦合特性进行了计算分析。理论和仿真结果表明:该磁轴承机械和磁路结构合理,悬浮力在平衡位置附近具有较好的线性和对称性,各自由度在平衡位置附近运动和磁路几乎没有耦合,对各自由度可采用分散的PID控制器进行控制,大大简化了控制系统。

The configuration and working principle of a novel radial-axial active magnetic bearing with sharing biased magnetic current are introduced.The flux path is calculated by using the equivalent magnetic circuit,and the mathematical models of suspension forces are deduced.According to design desire of the maximum suspension forces,the experiment prototype of the novel bearing is designed.The nonlinearity relations among axial and radial suspension forces and the coupling characteristics of movement and magnetic circuits between axial and radial around balanceable position are calculated and analyzed by Matlab software.The theory and simulation research results show that the mechanical configuration and magnetic circuits of the magnetic bearing are reasonable,the suspension forces have great linearity and symmetry around the balanceable position,and the movement and magnetic circuits among 3 degrees of freedom around the balanceable position have almost no coupling,and using independent PID control among 3 degrees of freedom for this novel magnetic bearing and greatly simplifying the control system.