01/02/23 16:11:12
@study @power-systems @electromagnetism
- Revise the rotating magnetic field.
- What is the behaviour of a rotor in this magnetic field.
- Have a look at imaginary numbers and phasors.
Time: 1hr 30m
- Maybe that’s a question for tomorrow, why is the mmf perpendicular to the axis of he magnet.
- It seems that it makes sense if you don’t think of it as a bar magnet but just use right hand rule and curl your fingers.
- In this way the net mmf, varies through time in a circle.
- Just might leave it for now, rotates due to superposition of forces at different currents flowing in coils.
- The magnetic field is proportional to the current, so it’s based on the phases.
Induced current in Rotor
- How does this generate torque.
- If we visualise the rotor as a loop, or a bar magnetic. It’s magnetic moment will follow the rotating field.
- There is a changing magnetic flux on the rotor, which induces a voltage in it and a current.
- If you just think of it as the magnetic moment catching up with the rotating magnetic field, it makes sense that it has to be going slower, otherwise it’ll stop. Just trying to see where the induced current notion comes into pay.
- How do we derive torque for each instant.