请教问题:永磁电机一般很少做成2极电机，请问是为何？

forlink

我公司已成功开发出2极30kW调速永磁同步电动机，电机振动，噪音，转矩脉动等指标都很好。
永磁电机铁芯比YE2异步电动机铁芯短10%，异步电动机采用的是2/3节距，永磁电动机为削弱转矩脉动采用的是5/6的节距比

czvmkl

2极转速多高？                    

CAE_BCG

I suppose the reasons as follows
The high speed motor with 2 pole numbers has long end winding, and it reduces the stiffness of the rotor which can cause the vibration and noise.
Also, the long end winding can induce much copper loss and deteriorate the efficiency.
Thus, 4 pole numbers is always selected.