基于探测线圈的无轴承异步电机气隙磁场测量方法研究

无轴承异步电机悬浮机理决定了转矩绕组和悬浮绕组两种气隙磁场的强耦合关系，而转矩绕组气隙磁场幅值和相位的准确识别又是实现径向悬浮控制的必要条件。文中提出采用探测线圈同时测量两套绕组的气隙磁场幅值和相位，从而避免了因电机参数测量误差或参数变化对悬浮控制性能带来的影响，而且使无轴承异步电机在超高速下运转成为可能。针对探测线圈安装位置的不同，分别详细论述了均匀分布角位置法、典型角位置法和解析法三种气隙磁密测量方法，并作了比较。实验结果验证了所述方法的有效性。

RESEARCH OF MEASURING THE AIRGAP FLUX OF BEARINGLESS INDUCTION MOTORS WITH SEARCH COILS

The suspending mechanism of the bearingless induction motors has determined the strong coupling relation between the airgap flux of motor winding and suspending winding. The magnetic forces are generated with two kinds of magnetic field interaction. Therefore it is very important to estimate or detect the distribution situation of magnetic fields. For this reason, the method of detecting the amplitude and orientation of the fields with search coils is proposed. Thus the effect on performance of suspending controlling is avoided, which is caused by the motor parameters change or error. And the ultra-high speed operation of the bearingless induction motor becomes possible. As different positions of search coils are concerned, three methods of detecting the airgap flux are discussed: evenly distributed angle position method, typical angle position method and analytic method. The experimental results have verified the validity of the proposed methods.