On Friday, June 3, 2016 at 9:39:09 AM UTC+5:30, Mark White wrote:
> On Wed, 01 Jun 2016 20:05:25 -0700, dakupoto wrote:
> 
> > I have created SPICE models for simple DC motors, and I am curious if
> > any electronics guru could point me to a SPICE model for a brush-less DC
> > motor.
> > I have searched on Google, but the SPICE models on various Web sites
> > always seem to be for the simple DC motor. Thanks in advance for your
> > help.
> I used this apps note about 15 years ago, I was surprised to find it 
> still available.  There's a chapter on BLDC simulation:
> http://www.it.uom.gr/project/digital/appnts.pdf

Thank you very much for the URL. I have created a simplified three stator SPICE model, and it runs fine, except that it is difficult to 
control the phase difference between the 
stator outputs. I am sure I am missing some 
key detail, which this detailed model will 
help rectify.

On Wed, 01 Jun 2016 20:05:25 -0700, dakupoto wrote:

> I have created SPICE models for simple DC motors, and I am curious if
> any electronics guru could point me to a SPICE model for a brush-less DC
> motor.
> I have searched on Google, but the SPICE models on various Web sites
> always seem to be for the simple DC motor. Thanks in advance for your
> help.
I used this apps note about 15 years ago, I was surprised to find it 
still available.  There's a chapter on BLDC simulation:
http://www.it.uom.gr/project/digital/appnts.pdf

On Wed, 01 Jun 2016 20:05:25 -0700, dakupoto wrote:

> I have created SPICE models for simple DC motors, and I am curious if
> any electronics guru could point me to a SPICE model for a brush-less DC
> motor.
> I have searched on Google, but the SPICE models on various Web sites
> always seem to be for the simple DC motor. Thanks in advance for your
> help.

What would you want to model?

You can do a simplified model of an ideal brushed motor fairly easily.  
But a simplified model of a BLDC motor is probably only going to be 
useful where a simplified model of a brushed motor would be.

As soon as you model the lack of commutation I think the motor model 
needs to be specific enough to your motor that you need to make a custom 
model, or you need a real motor expert to make a parameterized model.  In 
my experience, most motor experts aren't good enough circuit designers to 
know what we want, and most circuit designers (myself included, although 
for a circuit designer I suspect I've got more motor expertise than 99% 
out there) don't have enough motor chops.

So we circle back: what would you be doing with the model?  I suppose 
that if you want to push the motor RPM up close to the switching speed of 
your driver then having an accurate motor model would be a Good Thing -- 
but then you really want get down to details of how the reluctance is 
changing with angle, and the back-EMF, and all that lovely hard-to-define 
stuff.

-- 
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work!  See my website if you're interested
http://www.wescottdesign.com

I have created SPICE models for simple DC motors,
and I am curious if any electronics guru could
point me to a SPICE model for a brush-less DC motor.
I have searched on Google, but the SPICE models
on various Web sites always seem to be for the 
simple DC motor. Thanks in advance for your help.