In article ,
says...

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 agree, but it may be necessary to substitute diodes for the internal
elex.

I assume you're talking about substituting diodes for the
output stage of the amp here. Obviously if you're using the
motor as a generator, there's no need to actively commutate
the motor windings, but you do need to rectify the motor's
output if you want DC.

If the brushless motor has internal commutation electronics they may
need to be circumvented with diodes. Maybe some use external amps?


Sounds like we're imagining different classes of motor
here. When I hear "brushless motor" I think servo, where
the motor typically includes only the field windings, Hall
sensors to provide rotor position feedback for commutation,
and an encoder for position and velocity feedback to the
servo control loop. The power and control circuitry is
external to the motor.

I forget there are other motors for less demanding apps
that integrate the drive electronics in the motor package
with only the power leads, and perhaps speed control lines,
brought out. I suspect this is the sort of motor you're
talking about when you refer the "internal elex"?

Rectifying the output of the servo type would be trivial,
though the issue of voltage regulation you mentioned
elsewhere remains. As you say, not so simple for the
integrated motor.

Ned Simmons