30/01/23 11:01:13
@study @induction @power-systems @ac @electromagnetism
Time: 1hr
- Try and walkthrough graphical method of rotating magnetic field.
B-H relation
- Depending on the material, the flux can be different from the field strength. In ferromagnetic materials (with a net magnetism), the flux would be different as the superposition’s of the fields change the initial field strength value in an area of the material.
- where is dependent on the material (this is unity in free space).
Magnetomotive force (mmf)
- Defined as and in units of ampere-turn.
- Intuitavely I see it as the force withing coil (so not really including leakage/ parts of the field that cancel out).
- We use this to determine the superposition of magnetic force in the rotating magnetic field.
- How do we determine the direction of mmf?
- Assuming all flux is confined to the core. A ferromagnetic core amplifies the field lines.
- In the example it’s perpendicular to the axis of the magnet, maybe it’s talking about force of a charge?
Rotating Magnetic Field Winding
- Wiring is set up so that rotating field is generated. So just take it as given (in terms of current directions) for now.