异向旋转双机械口永磁电机磁路建模与场分析

Magnetic circuit modeling and field analysis for opposite-rotation dual mechanical ports PM machine

为研究单电口输入、双机械口输出异向旋转永磁同步电机的设计方法,对定子铁心中异向旋转磁场的耦合问题进行分析。介绍该电机的特殊结构和运行原理,针对双场耦合的特点,通过引入可变径向磁阻,建立等效磁网络图并化简得到等效磁路模型,并推导了磁阻计算方法,最后利用有限元分析方法验证等效磁路模型的正确性。等效磁路模型将双耦合磁场引起的并联磁路和串联磁路共同问题简化为单一的并联磁路问题。研究结果表明:转子异向旋转对气隙磁场影响小于5%,可以降低定子轭部的平均磁密。因此,设计该类电机时可在满足机械强度的情况下,尽可能地减小定子铁心的厚度。

To research design method of opposite rotation permanent magnet synchronous machine, which has characteristics of single electrical port input and dual mechanical ports output, the problem for the couple of two opposite-rotation magnetic fields in stator core was analyzed. The special structure and operation principle were introduced, in view of dual coupled magnetic field, the equivalent magnetic circuit model was achieved through simplifying equivalent magnetic net model established, by variable radial re- luctance introduced in. Meanwhile calculation for this reluctance was also induced, finally the correctness of equivalent magnetic circuit model was verified by finite element method（FEM）. The common problem of parallel-series magnetic circuit caused by two magnetic fields coupled is simplified to that of parallel magnetic circuit. The results show that the opposite rotation has no more than 5% effect on air-gap mag- netic field, and decreases average flux density in stator yoke, so the thickness of stator core should be as thin as possible for designing this kind of machine, when it meets mechanical strength.