【摘要】 交替极电机的永磁体被凸极铁心替换会形成不对称的空载气隙磁密，导致气隙磁密偶次谐波，进一步在相反电动势中感应出偶次谐波，增加电磁转矩脉动。当交替极永磁电机的极槽配合符合N_s=k(2P±1)(k是正整数，N_s和P分别是定子槽数和转子极对数)时，相反电势中会存在偶次谐波。为此，提出不等匝绕组技术消除交替极永磁电机的低次反电势偶次谐波，抑制电磁转矩脉动。首先推导了消除2次和4次反电势谐波的最优比例，然后以27槽30极电机为例，采用2维有限元方法对比分析了交替极和传统永磁电机的反电势和转矩特性，结果表明，采用不等匝绕组的交替极电机转矩脉动仅为1.2%,与传统电机相比下降了7.84个百分点，最后加工了不等匝绕组27槽30极交替极永磁电机对对理论和有限元分析进行了验证。更多还原

【Abstract】 For the consequent pole(CP) permanent magnet(PM) machine, its open-circuit air-gap flux density is asymmetry due to the replacement of a set of PMs by the salient iron core, resulting even-order harmonics in the air-gap flux density. The phase back electromotive force(back-EMF) even-order harmonics are induced due to the asymmetry of air-gap flux density, increasing the torque ripple. For the combinations of slot and pole satisfy N_s=k(2P±1)(k is a positive integer, N_s and P are the numbers of slot and pole pair, respectively), the even-order harmonics in the phase back-EMFs can’t be cancelled. Therefore, the unequal coil turns was proposed to eliminate the low even-order harmonics in phase back-EMFs, reducing the torque ripple. Firstly, the optimal coil turn ratio to eliminate the 2nd and 4th harmonics was derived. Then, the optimal coil turn ratios was implemented on the 27-slot/30-pole(27/30) CP PM machine by 2-dimension finite element(2-D FE) analysis, and the harmonics in phase back-EMFs, torque characteristics were compared comprehensively. The results show that the torque ripple of the CP PM machine with unequal number of coil turns is 1.2%, which is decreased by 7.84% compared to the traditional CP PM machine. Finally, the 27/30 CP SPM machine with unequal number of coil turns is fabricated and tested to verify the theoretical and FE analysis.更多还原