- #1
Vyse007
- 49
- 0
Hey fellas am having some trouble understanding the concept behind a rotating magnetic field. Looked up the wiki entry and a couple of other webpages, but only ended up getting more confused. I am well versed with all EM fundamentals, but still...
OK so in a basic alternator, we have a magnet rotating inside a conducting loop, or vice versa, as the requirement is relative motion between a conductor and a magnetic field so that the flux lines are cut and an EMF is induced. I get it up to this point.
Now I consider the stator with 3 coils, i.e a 3-phase system. So here does the rotating magnetic field refers to the field by the rotor(which is a permanent or electro magnet) since its the only thing that's rotating? If I power the coils with a 3-phase supply, then a magnetic field is set up in each of the coils and is 120 degree out of phase with each other, but how is this field rotating? Because in the wiki entry it says that the rotor will end up chasing this field as it will try to align the N or S pole of its magnetic field with that of the vector sum of the stator's field. I understand the mechanism behind that, but I don't see how the stator's field will rotate, and if this is the rotating magnetic field?
Also, if the rotor does move and ends up chasing the field of the stator, then how do I get 3 phase AC from this movement? And if the coils are to be driven by a 3 phase system in the 1st place, then that means you require 3phase current to make 3 phase current?
Any help would be appreciated. Thanks in advance.
OK so in a basic alternator, we have a magnet rotating inside a conducting loop, or vice versa, as the requirement is relative motion between a conductor and a magnetic field so that the flux lines are cut and an EMF is induced. I get it up to this point.
Now I consider the stator with 3 coils, i.e a 3-phase system. So here does the rotating magnetic field refers to the field by the rotor(which is a permanent or electro magnet) since its the only thing that's rotating? If I power the coils with a 3-phase supply, then a magnetic field is set up in each of the coils and is 120 degree out of phase with each other, but how is this field rotating? Because in the wiki entry it says that the rotor will end up chasing this field as it will try to align the N or S pole of its magnetic field with that of the vector sum of the stator's field. I understand the mechanism behind that, but I don't see how the stator's field will rotate, and if this is the rotating magnetic field?
Also, if the rotor does move and ends up chasing the field of the stator, then how do I get 3 phase AC from this movement? And if the coils are to be driven by a 3 phase system in the 1st place, then that means you require 3phase current to make 3 phase current?
Any help would be appreciated. Thanks in advance.