As I said, trying to align injected harmonic content to a signal in real-time
with the required accuracy, while the fundamental frequency is rapidly
changing, is not algorithmically possible given existing control schemes. Even
if you could figure out how to fix that, no one has come up with a
W/ DQ control most of these problems become FAR simpler problems to deal
with. But at that point you might as well go 'whole hog' and servo an
induction motor. VR motors are attractive becasue they use cheap simple
controls. Once you need a real processor an induction machine does a
better
Ok, I did not know that.
I would think though, that ripple and resolution are software issues which
should be readily solvable for a particular motor with the complexity
afforded by micros today, and only needs to be done once. The material cost
savings though, accumulate.
Regards
Roland
On 2
Turns out that ripple compensation is very doable at steady speeds (which is
why your new washing machine doesn't immediately shake itself to prices, where
SR motors are most common these days) but is very hard to do in real-time at
rapidly changing speeds, such as servoing applications.
The
--- On Fri, 5/3/13, N. Christopher Perry n_christopher_pe...@me.com wrote:
clip
The main scheme for accomplishing ripple reduction is
harmonic injection, but that requires very accurate phase
and magnitude targets, both of which can be expected to
change as a function of speed and torque.
Hi All
Can anyone tell me if they are actually using variable reluctance motors as
servos on CNC machines.
I find it odd that such a simple motor is not in greater use. The only
place I've ever seen them used was to position the head on old 8in floppy
drives.
Maybe they just don't have a good
I believe I have seen them used to advance the roller on an electric
typewriter. When the current is off, there's no cogging like hybrid steppers
have. That makes adjust paper height by hand seem normal for a typewriter.
Sent from my Kyocera Rise
Roland Jollivet roland.jolli...@gmail.com wrote:
They have a lot of torque ripple and are harder to micro step. Given these
factors their development is usually very targeted, so you won't generally find
them lying about in surplus piles.
For things like plasma and torch cutters they are probably a very cost
effective alternative, if you
