When does self-induction happen?

[Steven555]

I recently ran into a rabbit hole about self-induction. In high school, I was told the coil would generate induced current opposing the AC source current because the change of magnetic flux in the coil. So I get the impression that when there is changing magnetic flux, the induced current occurs. But the induced current will also generate magnetic filed that interact with original magnetic filed which means the overall magnetic filed changed again and another induced current will occur. It almost seems like it will always happen and never stops. I know there is something wrong but I could not figure out why. In self

There is another example: The single coil rotating in the fixed two poles magnetic filed. The current will be generated because the change of the magnetic flux. When there induced current generated (it almost like a single coil power by the AC source) through the coil, it generates another "new" magnetic field which interact with fixed magnetic field. This "new" changing magnetic field would cause another inductive current. It's like changing flux 1 - inductive current 1 - change flux 2 - inductive current 2 ... and never ends.

And also for generator stator winding, the inductive current will be generated in stator winding because of the rotating magnetic filed. If this induced current will have self-induction opposing the change of itself? If the current and voltage output from the common 3 phase generator are in phase? If there is any inductance causing the shifted current phase angle because of the self-induction?

When does self-induction happen? and when does it stop?

(Please bear with my language because English is not my first language. Let me know if I can clarify anything.)

 

[NFuller]

But the induced current will also generate magnetic filed that interact with original magnetic filed which means the overall magnetic filed changed again and another induced current will occur. It almost seems like it will always happen and never stops. I know there is something wrong but I could not figure out why. In self

This does happen, but not as you are imagining it. Real inductors have some resistance and self capacitance to them. This means that an inductor is a damped resonant circuit. If you rapidly change the current in an inductor, you tend to get decaying oscillations through the circuit.

The reason you are getting stuck is that you are taking the wording of Lenz's law a bit too literally, it is more just a tool to find the direction of an induced emf. In order to calculate the actual response of an inductor, you should just use Faraday's law.

 

[cnh1995]

The single coil rotating in the fixed two poles magnetic filed. The current will be generated because the change of the magnetic flux. When there induced current generated (it almost like a single coil power by the AC source) through the coil, it generates another "new" magnetic field which interact with fixed magnetic field. This "new" changing magnetic field would cause another inductive current. It's like changing flux 1 - inductive current 1 - change flux 2 - inductive current 2 ... and never ends.

An emf is induced in the generator coil when the coil is rotating in the external magnetic field as per Faraday's law. This happens because of the mutual inductance or magnetic coupling between the stator and rotor. The induced current will depend on what type of load is connected across the generator. This induced current in the coil will generate its own flux that will affect the original field flux. This is called 'armature reaction'. If the induced current has a real component, it will exert a braking torque on the rotor to slow it down and if the induced current has a reactive component, it will increase or decrease the main flux (look up magnetizing and demagnetizing armature reaction), which will alter the terminal voltage. Look up 'synchronous reactance'.

The red part in your post I quoted is related to the leakage inductance of the coil. Part of the flux of the rotor induced current is not coupled with the stator and it completes its path through air or surrounding medium. The changing induced current causes a changing leakage flux which causes an emf opposing the induced current. It is modeled as a voltage drop across the leakage inductance.

Here is a similar thread about Lenz's law in a transformer. See if it helps.
https://www.physicsforums.com/posts/5696172/.