There should be an absolute ("commutation") signal, in addition, usually Gray code, fairly coarse, to sense rotor position relative to poles. You'll need that, else you get a random movement on startup, even if you're clever enough to maintain sync using the quadrature encoder, once it's locked.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
That's not brushless DC.
That's a 3-phase permanent magnet synchronous motor.
The "modern" preferred type in robots, CNC axis drives, etc. Very flat torque, right down to 0RPM.
Needs an absolute reference for rotor position, relative to poles. 4-bit Gray code, repeated for each pole pair is adequate and usual.
How many poles?
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
And the last motor I looked at had a Gray code output on it that had
4 lines. This gives you 16 positions to work with between each phase so that the drive can hold the shaft in position easily..
They made some like that years ago, there was an index on the shaft and case so that you could find the pole line mechanically with out placing some DC in the coils to see where it locked position.
The power supply is a variable frequency three phase AC power supply. The motor may be specified with a locked rotor amperage - but you don't have to supply locked rotor current as a rule - just limit the current to practical values for normal operation - starting and running torque.
The "control side" is the hard part.
With a 160 V three phase AC motor you can probably get by with rectifying and filtering the 120 volt mains - steady state would be about 170 volts - via some H bridge switches into the windings.
International rectifier has loads of chips, pass transistors, and Application Notes for just what you want to do. Most of the VSD's I've played with, work with raw 120 or 240 single phase or three phase and don't step it up or down with a filtered linear or switching supply before it goes to the motor - that adds to the complexity and decreases efficiency.
With all the hoopla about unity phase green supplies that may be changing, but I haven't seen a drive like that makes use of that yet.
Down to zero control implies a synchronous motor with a magnet in the rotor just like a stepper motor. The encoder doesn't tell you much about the motor design.
BTW Sept "Power Electronics Technology" shows a chip for controlling stepper motors with a "micro-stepping" technique - or treating it just like a synchronous AC sine wave motor. Smoother operation from motors with fewer steps per rotation and less noise among the advantages of the technique.
It has three hall effect outputs, one for each of the three coils, and a one-pulse-per-revolution signal off the encoder for zeroing it. It's a BLDC motor with all the trimmings. I didn't mention any of that because I was asking about the power supply, not the control and feedback circuit.
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