SPICE model for BLDC ??

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.

 

[Tim Wescott]

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

 

[Mark White]

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 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.

 

See this: https://www.youtube.com/watch?v=6LOlN7QFiFQ