容错控制下电磁轴承磁极故障磁场解析

Magnetic Field Analysis of Magnetic Bearing Pole Fault under Fault-Tolerant Control

容错控制下电磁轴承出现磁极故障时,磁极间的磁耦合以及电磁力的非线性使得磁极面上无法产生需要的电磁力,会给转子的悬浮带来较大影响。针对这一问题,文中使用有限元软件仿真分析了强耦合和弱耦合结构电磁轴承出现单个和两个磁极故障时的磁场分布情况,并从磁场的角度对比分析了这两种结构对转子悬浮的影响。针对8极径向电磁轴承两个磁极间隙中存在较多的漏磁,而电磁轴承一般只能控制磁极端面上的磁通这一问题,文中对不同磁极数量的强耦合结构电磁轴承在定转子间气隙的磁通密度进行仿真分析。结果表明,12极电磁轴承的电流利用率超过99%,有效减少了电磁轴承的漏磁。

When an AMB has a magnetic pole failure under fault-tolerant control,the magnetic coupling between the magnetic poles and the nonlinearity of the electromagnetic force make it impossible to generate the required electromagnetic force on the magnetic pole surface,which will has a greater impact on the suspension of the rotor.To solve this problem,in this study,finite element software is used to simulate and analyze the magnetic field distribution of the AMB with strong coupling and weak coupling structure when single and two magnetic pole failures occur,and the influence of these two structures on the suspension of the rotor is compared and analyzed from the perspective of the magnetic field.In view of the fact that there is more magnetic flux leakage in the gap between the two magnetic poles of 8-pole radial AMB,the AMB generally can only control the magnetic flux on the magnetic poles,the magnetic flux density of the air gap between the rotors is simulated and analyzed.The simulation results show that the current utilization rate of the 12-pole AMB exceeds 99%,which effectively reduces the magnetic flux leakage.