裂齿式永磁游标电动机性能分析与比较

Comparison and analysis of split-tooth permanent magnet vernier motor

针对永磁游标电动机(permanent magnet vernier motor, PMVM)转矩密度大和功率密度高的特点,将其与传统永磁同步电动机(permanent magnet synchronous motor, PMSM)的性能进行比较研究.给出了6槽32极裂齿式PMVM的结构及工作原理,采用有限元仿真软件JMAG对其永磁磁场和电枢反应磁场的气隙磁密、空载感应电势、转矩、损耗等进行了分析,并与两台具有相同直径、轴长、定子齿数的PMSM进行了定量比较.结果表明:相比于6槽32极和6槽4极PMSM,6槽32极裂齿式PMVM平均转矩分别增加约45.0%和76.2%,转矩脉动减小约90.5%和95.0%,这揭示了PMVM转矩密度大、转矩脉动小的优点.然而,由于PMVM气隙中含有大量不同极对数、不同旋转速度的谐波磁场,导致其铁耗和永磁体涡流损耗较大.

To solve the problems of permanent magnet vernier motor(PMVM) with high torque density and high power density, the performance of PMVM was compared with that of traditional permanent magnet synchronous motor(PMSM). The structure and working principle of 6-slot/32-pole split-tooth PMVM were introduced. The air-gap flux density of PM field and armature reaction magnetic field(ARMF), the no-load EMF, the torque and the loss of 6-slot/32-pole split-tooth PMVM were analyzed by finite element simulation software of JMAG and quantitatively compared with those of two traditional PMSMs with the same diameter, stack length and number of stator teeth. The results show that compared with 6-slot/32-pole and 6-slot/4-pole PMSMs, the average torque of 6-slot/32-pole split-tooth PMVM is increased by about 45.0% and 76.2%, and the torque ripple is decreased about 90.5% and 95.0%, respectively. The results reveal that the split-tooth PMVM has merits of high torque density and low cogging torque. However, the air-gap flux density of the split-tooth PMVM contains large number of harmonics with different pole-pairs and rotation speeds, which leads to higher iron loss and PM eddy current loss.