Imagine simple 2 pole 3 phase induction motor, is there a mandatory pattern for the stator windings to creat a rotating magnetic field? Why must the angle between the coils be 120 mechanical degrees to create a rotating magnetic field? why can't I just put the coils in the stator in the order : aa'bb'cc' (each coil in 2 adjacent slots) ? and for 4 poles or more what is the rule?
I understand the math but is there anyway to imagine the whole process in my head? and the last question : How to consider a set of coils as a pole? like in the picture, why did he put the north pole and the south pole there and not vertical for example?
I am sorry if i'm not clear but these things are very confusing..