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

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 reluctance 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 magnetic 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.