×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

AC dynanamometer control loop?

AC dynanamometer control loop?

AC dynanamometer control loop?

(OP)
Hello,

I am planning to build a dynamometer like this one, i have experience with dynamometers, we have make software for engine test dynamomemters with eddy current brakes but never with AC asynchronous motors.



I know i need a vector control VFD, not v-f VFD, but my question is about how to control this dynamometer:

- Do we have to run a PID externaly to VFD unit? and then out controller gives target torque to VFD.
- or Do we have to gives directly target RPM and VFD have an internal speed PID?

Any requirement about control loop speed or any vector VFD would works?

I have very little experience setting VFD.
Any information is welcome, thanks
jlcortex

RE: AC dynanamometer control loop?

You need to run the VFD in Torque Mode (or Current Mode). The motor torque will be proportional to the VFD current command input.

RE: AC dynanamometer control loop?

I'm not so sure you need vector as you're not trying to hold some position or position relationship.

Notice the heater for dumping the power? If you get a regenerative drive the power can be fed back into the power grid without needing resistor banks or roasting your workspace. It also gives more use for the power connection you need to supply anyway so the drive is awake when it starts getting driven.

I certainly hope you protectively mount the drive on something so it isn't idiotically laying on the floor as depicted above. :)

You should confirm the drive you contemplate can "catch" a load. That means it is capable of engaging smoothly with an already spinning motor, not all drives can do that.

You'd probably want a drive that offers torque control.

Keith Cress
kcress - http://www.flaminsystems.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources