The purpose of coils is to increase the current for a given magnetic flux. Or decrease the RPM so less magnetic flux is necessary.
If there is any momentum in the system, that's just the normal inertia which has not yet been converted to electrical energy. Which, in turn, can be a result of the lack of coils not capturing the magnetic flux.
Your diagram is shit. It's a generator.
The purpose of coils is to increase the current for a given magnetic flux. Or decrease the RPM so less magnetic flux is necessary.
If there is any momentum in the system, that's just the normal inertia which has not yet been converted to electrical energy. Which, in turn, can be a result of the lack of coils not capturing the magnetic flux.