Yes yes I understand that, but what I mean to ask is what type of power is fed into the stator in order to cause the rotating magnetic field? Will it still rotate even if single phase power is used?
Hey Nickglyn!
The purpose of having a motor is so that the rotor can rotate continuously. Sure we can use single phase power and still achieve a similar effect, but the rotation of the rotor would not be continuous because there is a short pause between each change in polarity for a single phase current supply. So for instance changing from positive to negative would take 1 second then the rotor would stop rotating for one second until the next change in polarity (and hence magnetic field) occurs.
The purpose of us having a three-phase current supply is so that the rotation can be done seamlessly, i.e. without any stopping. When one pair of electromagnets stop acting as north and south poles, there will immediately be another phase of current being supplied to another pair of electromagnets created north and south poles. In this way a rotating magnetic field is achieved.
So yes we can use single phase but it wouldnt suit out purpose because it cannot facilitate the smooth and continuous rotation of the rotor.
Best Regards
Happy Physics Land