In article ,
says...

I wonder if a brushless DC motor would commutate without external
excitation. Something has to supply the electronics that makes it
brushless.


Every brushless motor I've worked with has had a PM
armature--no excitation required. Else why would it be
called brushless?

Though I've never tried it, I'd expect one would make a
very good 3-phase generator. They certainly do a good job
of pumping up the bus voltage on the servo amp when
delivering negative torque to an overhauling load.

I have used a brushless motor as a synchronous motor (i.e.,
no commutation) from the output of a VFD.

Ned Simmons